MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Biology Letters' source. Mon, 06 Feb 2012 14:26:00 +0100 http://www.medworm.com/index.php?rid=5636967&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22279152%26dopt%3DAbstract Authors: Hutchinson MN, Skinner A, Lee MS Abstract Tikiguania estesi is widely accepted to be the earliest member of Squamata, the reptile group that includes lizards and snakes. It is based on a lower jaw from the Late Triassic of India, described as a primitive lizard related to agamids and chamaeleons. However, Tikiguania is almost indistinguishable from living agamids; a combined phylogenetic analysis of morphological and molecular data places it with draconines, a prominent component of the modern Asian herpetofauna. It is unlikely that living agamids have retained the Tikiguania morphotype unchanged for over 216 Myr; it is much more conceivable that Tikiguania is a Quaternary or Late Tertiary agamid that was preserved in sediments derived from the Triassic beds that have a br... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5636967 Wed, 25 Jan 2012 05:00:00 +0100 5636967 http://www.medworm.com/index.php?rid=5636966&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22279153%26dopt%3DAbstract Authors: Habets MG, Brockhurst MA Abstract Antimicrobial peptides (AMPs) have been proposed as a promising new class of antimicrobials despite warnings that therapeutic use could drive the evolution of pathogens resistant to our own immunity peptides. Using experimental evolution, we demonstrate that Staphylococcus aureus rapidly evolved resistance to pexiganan, a drug-candidate for diabetic leg ulcer infections. Evolved resistance was costly in terms of impaired growth rate, but costs-of-resistance were completely ameliorated by compensatory adaptation. Crucially, we show that, in some populations, experimentally evolved resistance to pexiganan provided S. aureus with cross-resistance to human-neutrophil-defensin-1, a key component of the innate immune response to infection. This ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5636966 Wed, 25 Jan 2012 05:00:00 +0100 5636966 http://www.medworm.com/index.php?rid=5636952&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22279154%26dopt%3DAbstract Authors: Snyder HK, Maia R, D'Alba L, Shultz AJ, Rowe KM, Rowe KC, Shawkey MD Abstract Relative to other metazoans, the mammalian integument is thought to be limited in colour. In particular, while iridescence is widespread among birds and arthropods, it has only rarely been reported in mammals. Here, we examine the colour, morphology and optical mechanisms in hairs from four species of golden mole (Mammalia: Chrysochloridae) that are characterized by sheens ranging from purple to green. Microspectrophotometry reveals that this colour is weak and variable. Iridescent hairs are flattened and have highly reduced cuticular scales, providing a broad and smooth surface for light reflection. These scales form multiple layers of light and dark materials of consistent thickness, strikingly... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5636952 Wed, 25 Jan 2012 05:00:00 +0100 5636952 http://www.medworm.com/index.php?rid=5619140&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22258445%26dopt%3DAbstract This study examines the individual differentiation abilities of noisy miners (Manorina melanocephala), a species with one of the most complex avian societies known. Miners permanently occupy colonies numbering into hundreds of individuals. Within these colonies, cooperative coalitions form on a fission-fusion basis across numerous contexts, from social foraging through to mobbing predators. Birds often use individually distinctive 'chur' calls to recruit others to a caller's location, facilitating coalition formation. I used the habituation-discrimination paradigm to test the ability of miners to differentiate between the chur calls of two individuals that were both either: (i) familiar, or (ii) unfamiliar to the focal subject. This technique had not, to my knowledge, been used to assess v... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5619140 Wed, 18 Jan 2012 05:00:00 +0100 5619140 http://www.medworm.com/index.php?rid=5619139&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22258446%26dopt%3DAbstract Authors: Pommier T, Douzery EJ, Mouillot D Abstract Although environmental filtering has been observed to influence the biodiversity patterns of marine bacterial communities, it was restricted to the regional scale and to the species level, leaving the main drivers unknown at large biogeographic scales and higher taxonomic levels. Bacterial communities with different species compositions may nevertheless share phylogenetic lineages, and phylogenetic turnover (PT) among those communities may be surprisingly low along any biogeographic or environmental gradient. Here, we investigated the relative influence of environmental filtering and geographical distance on the PT between marine bacterial communities living more than 8000 km apart in contrasted abiotic conditions. PT was high bet... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5619139 Wed, 18 Jan 2012 05:00:00 +0100 5619139 http://www.medworm.com/index.php?rid=5619138&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22258447%26dopt%3DAbstract Authors: Boback SM, Hall AE, McCann KJ, Hayes AW, Forrester JS, Zwemer CF Abstract Many species of snakes use constriction-the act of applying pressure via loops of their trunk-to subdue and kill their prey. Constriction is costly and snakes must therefore constrict their prey just long enough to ensure death. However, it remains unknown how snakes determine when their prey is dead. Here, we demonstrate that boas (Boa constrictor) have the remarkable ability to detect a heartbeat in their prey and, based on this signal, modify the pressure and duration of constriction accordingly. We monitored pressure generated by snakes as they struck and constricted warm cadaveric rats instrumented with a simulated heart. Snakes responded to the beating heart by constricting longer and with grea... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5619138 Wed, 18 Jan 2012 05:00:00 +0100 5619138 http://www.medworm.com/index.php?rid=5619137&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22258448%26dopt%3DAbstract Authors: King KC, Seppälä O, Neiman M Abstract Ploidy-level variation is common and can drastically affect organismal fitness. We focus on the potential consequences of this variation for parasite resistance. First, we elucidate connections between ploidy variation and key factors determining resistance, including allelic diversity, gene expression and physiological condition. We then argue that systems featuring both natural and artificially manipulated ploidy variation should be used to evaluate whether ploidy level influences host-parasite interactions. PMID: 22258448 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5619137 Wed, 18 Jan 2012 05:00:00 +0100 5619137 http://www.medworm.com/index.php?rid=5619136&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22258449%26dopt%3DAbstract Authors: Richard F, Glass NL, Pringle A Abstract Fusions between individuals are a common feature of organisms with modular, indeterminate life forms, including plants, marine invertebrates and fungi. The consequences of fusion for an individual fungus are poorly understood. We used wild-type and fusion mutant strains of the genetic model Neurospora crassa to chronicle the fitness in two different laboratory habitats, and in each experiment started colonies from multiple different densities of asexual spores. On round Petri dishes, fusion enabled wild-type colonies to grow larger than mutant (soft) colonies; but in linear 'race tubes', the soft mutant always grew more quickly than the wild-type. Starting a colony with more spores always provided an advantage to a wild-type colony, ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5619136 Wed, 18 Jan 2012 05:00:00 +0100 5619136 http://www.medworm.com/index.php?rid=5619141&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22250131%26dopt%3DAbstract Authors: Brilot BO, Bateson M Abstract The majority of bird taxa perform water bathing, but little is known about the adaptive value of this behaviour. If bathing is important for feather maintenance then birds that have not bathed should have poorer feather condition, compromised escape ability and therefore increased responsiveness to cues of predation. We conducted two experiments examining the behaviour of captive starlings responding to conspecific alarm calls. Birds that had no access to bathing water showed a decreased willingness to feed and increased their vigilance behaviour following an alarm call. We argue that birds denied access to bathing water interpreted an ambiguous cue of threat as requiring more caution than birds that had access, consistent with higher levels o... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5619141 Mon, 16 Jan 2012 05:00:00 +0100 5619141 http://www.medworm.com/index.php?rid=5595404&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22237500%26dopt%3DAbstract Authors: Bermúdez-Cuamatzin E, Ríos-Chelén AA, Gil D, Garcia CM PMID: 22237500 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5595404 Wed, 11 Jan 2012 05:00:00 +0100 5595404 http://www.medworm.com/index.php?rid=5595403&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22237501%26dopt%3DAbstract Authors: Pölkki M, Krams I, Kangassalo K, Rantala MJ Abstract In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5595403 Wed, 11 Jan 2012 05:00:00 +0100 5595403 http://www.medworm.com/index.php?rid=5595402&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22237502%26dopt%3DAbstract Authors: Amiel JJ, Shine R Abstract A hatchling reptile's sex, body size and shape, and locomotor performance can be influenced not only by its genes, but also by the temperature that it experiences during incubation. Can incubation temperature also affect a hatchling's cognitive skills? In the scincid lizard Bassiana duperreyi, higher incubation temperatures enhanced the resultant hatchling's learning performance. Hence, factors such as maternal nest-site selection and climate change affect not only the size, shape and athletic abilities of hatchling reptiles, but also their ability to learn novel tasks. PMID: 22237502 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5595402 Wed, 11 Jan 2012 05:00:00 +0100 5595402 http://www.medworm.com/index.php?rid=5595401&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22237503%26dopt%3DAbstract Authors: Candiotti A, Zuberbühler K, Lemasson A Abstract Individually distinct vocalizations are widespread among social animals, presumably caused by variation in vocal tract anatomy. A less-explored source of individual variation is due to learned movement patterns of the vocal tract, which can lead to vocal convergence or divergence in social groups. We studied patterns of acoustic similarity in a social call produced by 14 female Diana monkeys (Cercopithecus diana) in two free-ranging groups. Calls showed variability in fundamental frequency contours owing to individual identity and external context. Vocal divergence increased significantly between females during poor visibility and tended to increase in the presence of neighbours. In contrast, vocal convergence increased sign... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5595401 Wed, 11 Jan 2012 05:00:00 +0100 5595401 http://www.medworm.com/index.php?rid=5595400&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22237504%26dopt%3DAbstract Authors: Kahn AT, Livingston JD, Jennions MD Abstract A poor start in life owing to a restricted diet can have readily detectable detrimental consequences for many adult life-history traits. However, some costs such as smaller adult body size are potentially eliminated when individuals modify their development. For example, male mosquitofish (Gambusia holbrooki) that have reduced early food intake undergo compensatory growth and delay maturation so that they eventually mature at the same size as males that develop normally. But do subtle effects of a poor start persist? Specifically, does a male's developmental history affect his subsequent attractiveness to females? Females prefer to associate with larger males but, controlling for body length, we show that females spent less time... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5595400 Wed, 11 Jan 2012 05:00:00 +0100 5595400 http://www.medworm.com/index.php?rid=5576676&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22219389%26dopt%3DAbstract Authors: Ganswindt A, Brown JL, Freeman EW, Kouba AJ, Penfold LM, Santymire RM, Vick MM, Wielebnowski N, Willis EL, Milnes MR Abstract Hormone analysis is a precise and widely accepted tool for monitoring reproductive function and responses to stressors. Although hormones are present and can be measured in various biological matrices, non-invasive methods have gained popularity over the past 30 years as a more practical approach for assessing ovarian, testicular and, more recently, adrenocortical activity in intractable wildlife species. Non-invasive hormone monitoring also has been key to understanding biological mechanisms related to observed behaviours of captive and free-ranging animals. Despite the increasing popularity of this research field, wildlife endocrinologists have no... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5576676 Wed, 04 Jan 2012 05:00:00 +0100 5576676 http://www.medworm.com/index.php?rid=5576675&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22219390%26dopt%3DAbstract In this study, we show that field-experienced male Schizocosa ocreata wolf spiders exhibit eavesdropping and signal matching when exposed to video playback of courting male conspecifics. Male spiders had longer bouts of interaction with a courting male stimulus, and more bouts of courtship signalling during and after the presence of a male on the video screen. Rates of courtship (leg tapping) displayed by individual focal males were correlated with the rates of the video exemplar to which they were exposed. These findings suggest male wolf spiders might gain information by eavesdropping on conspecific courtship and adjust performance to match that of rivals. This represents a novel finding, as these behaviours have previously been seen primarily among vertebrates. PMID: 22219390 [PubMe... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5576675 Wed, 04 Jan 2012 05:00:00 +0100 5576675 http://www.medworm.com/index.php?rid=5576674&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22219391%26dopt%3DAbstract Authors: Krause ET, Krüger O, Kohlmeier P, Caspers BA Abstract The ability to recognize close relatives in order to cooperate or to avoid inbreeding is widespread across all taxa. One accepted mechanism for kin recognition in birds is associative learning of visual or acoustic cues. However, how could individuals ever learn to recognize unfamiliar kin? Here, we provide the first evidence for a novel mechanism of kin recognition in birds. Zebra finch (Taeniopygia guttata) fledglings are able to distinguish between kin and non-kin based on olfactory cues alone. Since olfactory cues are likely to be genetically based, this finding establishes a neglected mechanism of kin recognition in birds, particularly in songbirds, with potentially far-reaching consequences for both kin selection... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5576674 Wed, 04 Jan 2012 05:00:00 +0100 5576674 http://www.medworm.com/index.php?rid=5576673&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22219392%26dopt%3DAbstract We report the detection of two additional eukaryotic porin-like sequences in T. brucei. By bioinformatic means, we classify both as putative VDAC isoforms. PMID: 22219392 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5576673 Wed, 04 Jan 2012 05:00:00 +0100 5576673 http://www.medworm.com/index.php?rid=5576672&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22219393%26dopt%3DAbstract Authors: Sugimoto TN, Ishikawa Y Abstract Endosymbiotic bacteria of the genus Wolbachia induce diverse reproductive alterations in their insect hosts. Wolbachia (wSca) infecting the moth Ostrinia scapulalis causes unusual male killing, in which males (genotype: ZZ) selectively die during embryonic and larval development, whereas females (genotype: ZW), in turn, selectively die when cured of infection. To gain insight into the interaction between wSca and the host, we analysed phenotypic and genetic sexes of the embryos and larvae of normal, wSca-infected, and infected-and-cured O. scapulalis by diagnosing the sex-specifically spliced transcripts of Osdsx-a homologue of the sex-determining gene doublesex-and sex chromatin in interphase nuclei, respectively. It was observed that the ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5576672 Wed, 04 Jan 2012 05:00:00 +0100 5576672 http://www.medworm.com/index.php?rid=5576671&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22219394%26dopt%3DAbstract Authors: Zhu M, Yu X, Choo B, Wang J, Jia L Abstract Almost all gnathostomes or jawed vertebrates (including osteichthyans, chondrichthyans, 'acanthodians' and most placoderms) possess paired pectoral and pelvic fins. To date, it has generally been believed that antiarch placoderms (extinct armoured jawed fishes from the Silurian-Devonian periods) lacked pelvic fins. The putative absence of pelvic fins is a key character bearing on the monophyly or paraphyly of placoderms. It also has far-reaching implications for studying the sequence of origin of pelvic girdles versus that of movable jaws in the course of vertebrate evolution. Parayunnanolepis xitunensis represents the only example of a primitive antiarch with extensive post-thoracic preservation, and its original description has... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5576671 Wed, 04 Jan 2012 05:00:00 +0100 5576671 http://www.medworm.com/index.php?rid=5544705&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22188673%26dopt%3DAbstract Authors: Paaijmans KP, Blanford S, Chan BH, Thomas MB Abstract The development rate of parasites and pathogens within vectors typically increases with temperature. Accordingly, transmission intensity is generally assumed to be higher under warmer conditions. However, development is only one component of parasite/pathogen life history and there has been little research exploring the temperature sensitivity of other traits that contribute to transmission intensity. Here, using a rodent malaria, we show that vector competence (the maximum proportion of infectious mosquitoes, which implicitly includes parasite survival across the incubation period) tails off at higher temperatures, even though parasite development rate increases. We also show that the standard measure of the parasite i... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5544705 Wed, 21 Dec 2011 05:00:00 +0100 5544705 http://www.medworm.com/index.php?rid=5544704&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22188674%26dopt%3DAbstract Authors: Snaddon JL, Turner EC, Fayle TM, Khen CV, Eggleton P, Foster WA Abstract The exceptionally high species richness of arthropods in tropical rainforests hinges on the complexity of the forest itself: that is, on features such as the high plant diversity, the layered nature of the canopy and the abundance and the diversity of epiphytes and litter. We here report on one important, but almost completely neglected, piece of this complex jigsaw-the intricate network of rhizomorph-forming fungi that ramify through the vegetation of the lower canopy and intercept falling leaf litter. We show that this litter-trapping network is abundant and intercepts substantial amounts of litter (257.3 kg ha(-1)): this exceeds the amount of material recorded in any other rainforest litter-trappin... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5544704 Wed, 21 Dec 2011 05:00:00 +0100 5544704 http://www.medworm.com/index.php?rid=5526347&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171018%26dopt%3DAbstract Authors: Forsman JT, Seppänen JT, Nykänen IL Abstract Optimal investment in offspring is important in maximizing lifetime reproductive success. Yet, very little is known how animals gather and integrate information about environmental factors to fine tune investment. Observing the decisions and success of other individuals, particularly when those individuals initiate breeding earlier, may provide a way for animals to quickly arrive at better breeding investment decisions. Here we show, with a field experiment using artificial nests appearing similar to resident tit nests with completed clutches, that a migratory bird can use the observed high and low clutch size of a resident competing bird species to increase and decrease clutch size and egg mass, accordingly. Our results demon... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526347 Wed, 14 Dec 2011 05:00:00 +0100 5526347 http://www.medworm.com/index.php?rid=5526346&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171019%26dopt%3DAbstract Authors: Vogel ER, Knott CD, Crowley BE, Blakely MD, Larsen MD, Dominy NJ Abstract Protein is a limiting resource that is essential to the growth, maintenance and reproduction of tropical frugivores, yet few studies have examined how wild animals maintain protein balance. During chronic periods of fruit scarcity, Bornean orangutans (Pongo pygmaeus) often catabolize their own fat reserves despite unusually low metabolic requirements. Such energy deficits suggest a marginal existence, and raise the possibility that orangutans also endure periods of negative protein balance. To test this hypothesis, we conducted the first study of protein cycling in a wild primate. Our five year analysis of urinary metabolites revealed evidence of protein recycling when fruit was scarce. During these ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526346 Wed, 14 Dec 2011 05:00:00 +0100 5526346 http://www.medworm.com/index.php?rid=5526345&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171020%26dopt%3DAbstract Authors: Martínez-Vilalta J, Lloret F, Breshears DD Abstract A large number of episodes of forest mortality associated with drought and heat stress have been detected worldwide in recent decades, suggesting that some of the world's forested ecosystems may be already responding to climate change. Here, we summarize a special session titled 'Drought-induced forest decline: causes, scope and implications' within the 12th European Ecological Federation Congress, held in Ávila (Spain) from 25 to 29 September 2011. The session focused on the interacting causes and impacts of die-off episodes at the community and ecosystem levels, and highlighted recent events of drought- and heat-related tree decline, advances in understanding mechanisms and in predicting mortality events, and diverse ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526345 Wed, 14 Dec 2011 05:00:00 +0100 5526345 http://www.medworm.com/index.php?rid=5526344&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171021%26dopt%3DAbstract Authors: Charlesworth B PMID: 22171021 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526344 Wed, 14 Dec 2011 05:00:00 +0100 5526344 http://www.medworm.com/index.php?rid=5526343&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171022%26dopt%3DAbstract Authors: Barger CP, Kitaysky AS Abstract Dietary segregation is essential for the coexistence of closely related species of animals. However, little is known about how changes in availability of food resources might affect trophic interactions of wild animals breeding in sympatry. Here, we examined how interannual variations in relative food availability (as reflected in blood levels of stress hormone corticosterone, CORT) affect food partitioning (assessed via a comparison of stable isotope δ(15)N and δ(13)C ratios of blood) between the common murre (Uria aalge) and thick-billed murre (Uria lomvia), breeding on a single colony in the Bering Sea. During a 6-year study, CORT varied among years but not between species, whereas stable isotope ratios varied among years and between sp... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526343 Wed, 14 Dec 2011 05:00:00 +0100 5526343 http://www.medworm.com/index.php?rid=5526342&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171023%26dopt%3DAbstract Authors: Dean I, Siva-Jothy MT Abstract Although we are relatively naked in comparison with other primates, the human body is covered in a layer of fine hair (vellus and terminal hair) at a relatively high follicular density. There are relatively few explanations for the evolutionary maintenance of this type of human hair. Here, we experimentally test the hypothesis that human fine body hair plays a defensive function against ectoparasites (bed bugs). Our results show that fine body hair enhances the detection of ectoparasites through the combined effects of (i) increasing the parasite's search time and (ii) enhancing its detection. PMID: 22171023 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526342 Wed, 14 Dec 2011 05:00:00 +0100 5526342 http://www.medworm.com/index.php?rid=5526341&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22171024%26dopt%3DAbstract This study tests whether melatonin is capable of influencing the timing of clutch initiation in wild female songbirds. Free-living female great tits (Parus major) treated with melatonin-filled implants prior to the breeding season initiated their first clutch of the season significantly later than females carrying an empty implant. Melatonin treatment did not affect clutch size. Further, melatonin treatment did not delay the onset of daily activity in the wild nor adversely affect body mass in captivity compared with controls. These data suggest a previously unknown role for this hormone in regulating the timing of clutch initiation in the wild. PMID: 22171024 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526341 Wed, 14 Dec 2011 05:00:00 +0100 5526341 http://www.medworm.com/index.php?rid=5526391&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22158734%26dopt%3DAbstract Authors: Leal M, Powell BJ PMID: 22158734 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526391 Wed, 07 Dec 2011 05:00:00 +0100 5526391 http://www.medworm.com/index.php?rid=5526390&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22158735%26dopt%3DAbstract Authors: Vasconcelos M, Monteiro T, Kacelnik A PMID: 22158735 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526390 Wed, 07 Dec 2011 05:00:00 +0100 5526390 http://www.medworm.com/index.php?rid=5526376&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22158736%26dopt%3DAbstract Authors: Cui J, Tang Y, Narins PM Abstract During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure information that can be recognized by females. Inside-nest calls consisted of notes with energy concentrated at lower frequency ranges and longer note durations when compared with outside-nest calls. Centre frequencies and note durations of the inside call... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526376 Wed, 07 Dec 2011 05:00:00 +0100 5526376 http://www.medworm.com/index.php?rid=5526351&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22158737%26dopt%3DAbstract We report on a newly discovered cockroach (Saltoblattella montistabularis) from South Africa, which jumps and therefore differs from all other extant cockroaches that have a scuttling locomotion. In its natural shrubland habitat, jumping and hopping accounted for 71 per cent of locomotory activity. Jumps are powered by rapid and synchronous extension of the hind legs that are twice the length of the other legs and make up 10 per cent of the body weight. In high-speed images of the best jumps the body was accelerated in 10 ms to a take-off velocity of 2.1 m s(-1) so that the cockroach experienced the equivalent of 23 times gravity while leaping a forward distance of 48 times its body length. Such jumps required 38 µJ of energy, a power output of 3.4 mW and exerted a ground reaction force t... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526351 Wed, 07 Dec 2011 05:00:00 +0100 5526351 http://www.medworm.com/index.php?rid=5526348&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22158738%26dopt%3DAbstract Authors: Kjellerup S, Kiørboe T Abstract Small cruising zooplankton depend on remote prey detection and active prey capture for efficient feeding. Direct, passive interception of prey is inherently very inefficient at low Reynolds numbers because the viscous boundary layer surrounding the approaching predator will push away potential prey. Yet, direct interception has been proposed to explain how rapidly cruising, blind copepods feed on non-motile phytoplankton prey. Here, we demonstrate a novel mechanism for prey detection in a cruising copepod, and describe how motile and non-motile prey are discovered by hydromechanical and tactile or, likely, chemical cues, respectively. PMID: 22158738 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526348 Wed, 07 Dec 2011 05:00:00 +0100 5526348 http://www.medworm.com/index.php?rid=5526396&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130170%26dopt%3DAbstract Authors: Suleman N, Raja S, Compton SG Abstract Male insects rarely collaborate with each other, but pollinator fig wasps (Hymenoptera: Agaonidae) are said to be an exception. Immature fig wasps feed on galled ovules located inside figs, the inflorescences of Ficus species (Moraceae). After mating, adult pollinator males chew communal exit-holes that allow mated females (which are often also their siblings) to escape. Figs also support non-pollinating fig wasps (NPFWs), some of which produce exit-holes independently. We determined whether collaboration between pollinator males (Kradibia tentacularis from Ficus montana) was necessary for the release of their females, and used the relationship between male numbers and likelihood of success to measure the extent of cooperation during ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526396 Wed, 30 Nov 2011 05:00:00 +0100 5526396 http://www.medworm.com/index.php?rid=5526395&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130171%26dopt%3DAbstract We report on the main insights obtained from this symposium. PMID: 22130171 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526395 Wed, 30 Nov 2011 05:00:00 +0100 5526395 http://www.medworm.com/index.php?rid=5526394&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130172%26dopt%3DAbstract Authors: Cooling M, Hartley S, Sim DA, Lester PJ Abstract Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9-15.3 years). Resident ant communities had recovered or partly recovered after their collapse. Our models suggest that climate change will delay colony collapse, as increasing temperature and decreasing rainfall significantly increased their longevity, but only by a few years. Economic and environment... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526394 Wed, 30 Nov 2011 05:00:00 +0100 5526394 http://www.medworm.com/index.php?rid=5526393&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130173%26dopt%3DAbstract Authors: Baeta R, Bélisle M, Garant D Abstract The control of primary sex-ratio by vertebrates has become a major focus in biology in recent years. Evolutionary theory predicts that a differential effect of maternal characteristics on the fitness of sons and daughters is an important route, whereby selection is expected to favour a bias towards the production of one sex. However, despite experimental evidence for adaptive brood sex-ratio manipulation, support for this prediction remains a major challenge in vertebrates where inconsistencies between correlative studies are frequently reported. Here, we used a large dataset (2215 nestlings over 3 years) from a wild population of tree swallows (Tachycineta bicolor) and show that variations in breeding conditions affect female sex all... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526393 Wed, 30 Nov 2011 05:00:00 +0100 5526393 http://www.medworm.com/index.php?rid=5526392&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130174%26dopt%3DAbstract Authors: Mattoso TC, Moreira DD, Samuels RI Abstract Although only discovered in 1999, the symbiotic filamentous actinobacteria present on the integument of certain species of leaf-cutting ants have been the subject of intense research. These bacteria have been shown to specifically suppress fungal garden parasites by secretion of antibiotics. However, more recently, a wider role for these bacteria has been suggested from research revealing their generalist anti-fungal activity. Here we show, for the first time, evidence for a role of these bacteria in the defence of young worker ants against a fungal entomopathogen. Experimental removal of the bacterial bio-film using an antibiotic resulted in a significant increase in susceptibility of worker ants to infection by the entomopathog... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526392 Wed, 30 Nov 2011 05:00:00 +0100 5526392 http://www.medworm.com/index.php?rid=5526411&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22114322%26dopt%3DAbstract Authors: Barribeau SM, Villinger J, Waldman B Abstract Major histocompatibility complex (MHC) genes determine immune repertoires and social preferences of vertebrates. Immunological regulation of microbial assemblages associated with individuals influences their sociality, and should also affect their life-history traits. We exposed Xenopus laevis tadpoles to water conditioned by adult conspecifics. Then, we analysed tadpole growth, development and survivorship as a function of MHC class I and class II peptide-binding region amino acid sequence similarities between tadpoles and frogs that conditioned the water to which they were exposed. Tadpoles approached metamorphosis earlier and suffered greater mortality when exposed to immunogenetically dissimilar frogs. The results suggest t... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526411 Wed, 23 Nov 2011 05:00:00 +0100 5526411 http://www.medworm.com/index.php?rid=5526410&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22114323%26dopt%3DAbstract Authors: Takahashi T, Ochi H, Kohda M, Hori M Abstract A focus on pair bonds between males and females is fundamental to study the evolution of social organization. Because pair bonds are generally identified from direct observations of pairs that maintain physical proximity, pair bonds may have been overlooked in animals that do not exhibit such visible pairs. The Lake Tanganyika cichlid fish Xenotilapia rotundiventralis forms schools that consist of mouthbrooding and non-brooding adults in mid-water, and visible pairs are not recognized. A previous study suggested that mouthbrooding females transfer fractions of the young to males when the young become large. However, it remains a mystery whether the mating pairs maintain pair bonds so that the females can transfer the young to t... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526410 Wed, 23 Nov 2011 05:00:00 +0100 5526410 http://www.medworm.com/index.php?rid=5526409&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22114324%26dopt%3DAbstract Authors: Smith AB, Barrett PM Abstract The history of life on this planet is gleaned from analysing how fossils are distributed through time and space. While these patterns are now rather securely known, at least for well-studied parts of the world, their interpretation remains far from simple. Fossils preserve only partial data from which to reconstruct their biology and the geological record is incomplete and biased, so that taxonomic ranges and palaeocommunity structure are imperfectly known. To better understand the often highly complex deep-time processes that gave rise to the empirical fossil record, palaeontologists have turned to modelling the past. Here, we summarize a series of 11 papers that showcase where modelling the past is being applied to advance our understanding ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526409 Wed, 23 Nov 2011 05:00:00 +0100 5526409 http://www.medworm.com/index.php?rid=5526412&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090207%26dopt%3DAbstract Authors: Dalmaso M, Pavan G, Castelli L, Galfano G Abstract Humans tend to shift attention in response to the averted gaze of a face they are fixating, a phenomenon known as gaze cuing. In the present paper, we aimed to address whether the social status of the cuing face modulates this phenomenon. Participants were asked to look at the faces of 16 individuals and read fictive curriculum vitae associated with each of them that could describe the person as having a high or low social status. The association between each specific face and either high or low social status was counterbalanced between participants. The same faces were then used as stimuli in a gaze-cuing task. The results showed a greater gaze-cuing effect for high-status faces than for low-status faces, independently of... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526412 Fri, 18 Nov 2011 05:00:00 +0100 5526412 http://www.medworm.com/index.php?rid=5526420&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090199%26dopt%3DAbstract Authors: Peng SE, Chen CS, Song YF, Huang HT, Jiang PL, Chen WN, Fang LS, Lee YC Abstract The endosymbiotic relationship between coral hosts and dinoflagellates of the genus Symbiodinium is critical for the growth and productivity of coral reef ecosystems. Here, synchrotron radiation-based infrared microspectroscopy was applied to examine metabolite concentration differences between endosymbiotic (within the anemone Aiptasia pulchella) and free-living Symbiodinium over the light-dark cycle. Significant differences in levels of lipids, nitrogenous compounds, polysaccharides and putative cell wall components were documented. Compared with free-living Symbiodinium, total lipids, unsaturated lipids and polysaccharides were relatively enriched in endosymbiotic Symbiodinium during both l... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526420 Wed, 16 Nov 2011 05:00:00 +0100 5526420 http://www.medworm.com/index.php?rid=5526419&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090200%26dopt%3DAbstract Authors: Wascher CA, Weiß BM, Arnold W, Kotrschal K Abstract In group-living vertebrates, reliable social allies play a decisive role in dealing with stressors. For example, support by social allies is known to dampen glucocorticoid responses. It remains unknown, however, how social embedding affects the sympatho-adrenergic axis as indicated by heart rate (HR) in non-human animals. We studied the relationships between HR, pair-bond status and distance from the pair-partner in twenty-five free-ranging greylag geese (Anser anser) in a natural social environment. In three individuals, we investigated HR responses following partner loss. Overall, we found a context- and sex-dependent difference in HR between paired and unpaired individuals, paired males having a lower HR during agonis... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526419 Wed, 16 Nov 2011 05:00:00 +0100 5526419 http://www.medworm.com/index.php?rid=5526418&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090201%26dopt%3DAbstract Authors: Portugal SJ, Green JA, White CR, Guillemette M, Butler PJ Abstract Hypertrophy of the flight muscles is regularly observed in birds prior to long-distance migrations. We tested the hypothesis that a large migratory bird would increase flight behaviour prior to migration, in order to cause hypertrophy of the flight muscles, and upregulate key components of the aerobic metabolic pathways. Implantable data loggers were used to record year-round heart rate in six wild barnacle geese (Branta leucopsis), and the amount of time spent in flight each day was identified. Time in flight per day did not significantly increase prior to either the spring or the autumn migration, both between time periods prior to migration (5, 10 and 15 days), or when compared with a control period of l... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526418 Wed, 16 Nov 2011 05:00:00 +0100 5526418 http://www.medworm.com/index.php?rid=5526417&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090202%26dopt%3DAbstract Authors: Mallet MA, Kimber CM, Chippindale AK Abstract Adult reproductive success can account for a large fraction of male fitness, however, we know relatively little about the susceptibility of reproductive traits to mutation-accumulation (MA). Estimates of the mutational rate of decline for adult fitness and its components are controversial in Drosophila melanogaster, and post-copulatory performance has not been examined. We therefore separately measured the consequences of MA for total male reproductive success and its major pre-copulatory and post-copulatory components: mating success and sperm competitive success. We also measured juvenile viability, an important fitness component that has been well studied in MA experiments. MA had strongly deleterious effects on both male vi... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526417 Wed, 16 Nov 2011 05:00:00 +0100 5526417 http://www.medworm.com/index.php?rid=5526416&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090203%26dopt%3DAbstract This study provides, to our knowledge, the first quantitative estimates of intake rate for this species. PMID: 22090203 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526416 Wed, 16 Nov 2011 05:00:00 +0100 5526416 http://www.medworm.com/index.php?rid=5526415&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090204%26dopt%3DAbstract Authors: Astley HC, Roberts TJ Abstract Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid jo... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526415 Wed, 16 Nov 2011 05:00:00 +0100 5526415 http://www.medworm.com/index.php?rid=5526414&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090205%26dopt%3DAbstract Authors: Taylor CM, Hall RJ Abstract Metapopulation models are widely used to study species that occupy patchily distributed habitat, but are rarely applied to migratory species, because of the difficulty of identifying demographically independent subpopulations. Here, we extend metapopulation theory to describe the directed seasonal movement of migratory populations between two sets of habitat patches, breeding and non-breeding, with potentially different colonization and extinction rates between patch types. By extending the classic metapopulation model, we show that migratory metapopulations will persist if the product of the two colonization rates exceeds the product of extinction rates. Further, we develop a spatially realistic migratory metapopulation model and derive a lands... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526414 Wed, 16 Nov 2011 05:00:00 +0100 5526414 http://www.medworm.com/index.php?rid=5526413&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22090206%26dopt%3DAbstract Authors: Lock JE Abstract Parental effects on offspring life-history traits are common and increasingly well-studied. However, the extent to which these effects persist into offspring in subsequent generations has received less attention. In this experiment, maternal and paternal effects on offspring and grand-offspring were investigated in the biparental burying beetle Nicrophorus vespilloides, using a split-family design. This allowed the separation of prenatal and postnatal transgenerational effects. Grandparent and parent gender were found to have a cumulative effect on offspring development and may provide a selection pressure on the division of parental investment in biparental species. PMID: 22090206 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5526413 Wed, 16 Nov 2011 05:00:00 +0100 5526413 http://www.medworm.com/index.php?rid=5412790&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22072281%26dopt%3DAbstract Authors: Sternalski A, Mougeot F, Bretagnolle V Abstract Permanent female mimicry, in which adult males express a female phenotype, is known only from two bird species. A likely benefit of female mimicry is reduced intrasexual competition, allowing female-like males to access breeding resources while avoiding costly fights with typical territorial males. We tested this hypothesis in a population of marsh harriers Circus aeruginosus in which approximately 40 per cent of sexually mature males exhibit a permanent, i.e. lifelong, female plumage phenotype. Using simulated territorial intrusions, we measured aggressive responses of breeding males towards conspecific decoys of females, female-like males and typical males. We show that aggressive responses varied with both the type of deco... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5412790 Wed, 09 Nov 2011 05:00:00 +0100 5412790 http://www.medworm.com/index.php?rid=5412789&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22072282%26dopt%3DAbstract Authors: Ramsayer J, Fellous S, Cohen JE, Hochberg ME Abstract Populations vary in time and in space, and temporal variation may differ from spatial variation. Yet, in the past half century, field data have confirmed both the temporal and spatial forms of Taylor's power Law, a linear relationship between log(variance) and log(mean) of population size. Recent theory predicted that competitive species interactions should reduce the slope of the temporal version of Taylor's Law. We tested whether this prediction applied to the spatial version of Taylor's Law using simple, well-controlled laboratory populations of two species of bacteria that were cultured either separately or together for 24 h in media of widely varying nutrient richness. Experimentally, the spatial form of Taylor's L... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5412789 Wed, 09 Nov 2011 05:00:00 +0100 5412789 http://www.medworm.com/index.php?rid=5412788&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22072283%26dopt%3DAbstract Authors: Dunlop JA, Wirth S, Penney D, McNeil A, Bradley RS, Withers PJ, Preziosi RF Abstract High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44-49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we b... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5412788 Wed, 09 Nov 2011 05:00:00 +0100 5412788 http://www.medworm.com/index.php?rid=5412787&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22072284%26dopt%3DAbstract Authors: Gvozdík L Abstract Thermoregulatory behaviour represents an important component of ectotherm non-genetic adaptive capacity that mitigates the impact of ongoing climate change. The buffering role of behavioural thermoregulation has been attributed solely to the ability to maintain near optimal body temperature for sufficiently extended periods under altered thermal conditions. The widespread occurrence of plastic modification of target temperatures that an ectotherm aims to achieve (preferred body temperatures) has been largely overlooked. I argue that plasticity of target temperatures may significantly contribute to an ectotherm's adaptive capacity. Its contribution to population persistence depends on both the effectiveness of acute thermoregulatory adjustments (reactivi... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5412787 Wed, 09 Nov 2011 05:00:00 +0100 5412787 http://www.medworm.com/index.php?rid=5376900&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22048889%26dopt%3DAbstract We examined the dynamics of height dimorphism in Rumex hastatulus, an annual, wind-pollinated, dioecious plant from the southern USA. A field survey of seven populations indicated that females were significantly taller than males at seed maturity. However, a glasshouse experiment revealed a more complex pattern of height growth during the life cycle. No dimorphism was evident prior to reproduction for six of seven populations, but at flowering, males were significantly taller than females in all populations. This pattern was reversed at reproductive maturity, consistent with field observations. Males flowered later than females and the degree of height dimorphism was greater in populations with a later onset of male flowering. We discuss the potential adaptive significance of temporal chan... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376900 Wed, 02 Nov 2011 04:00:00 +0100 5376900 http://www.medworm.com/index.php?rid=5376899&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22048890%26dopt%3DAbstract Authors: Cheke LG, Clayton NS Abstract Western scrub-jays (Aphelocoma californica) have been shown to overcome present satiety to cache food they will desire in the future. Here, we show that another corvid, the Eurasian jay (Garrulus glandarius), can distinguish between two distinct future desires and plan for each appropriately, despite experiencing a conflicting current motivation. We argue that these data address the criticisms of previous work, and suggest a way in which associative learning processes and future-oriented cognition may combine to allow prospective behaviour. PMID: 22048890 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376899 Wed, 02 Nov 2011 04:00:00 +0100 5376899 http://www.medworm.com/index.php?rid=5376898&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22048891%26dopt%3DAbstract Authors: Lesbarrères D, Balseiro A, Brunner J, Chinchar VG, Duffus A, Kerby J, Miller DL, Robert J, Schock DM, Waltzek T, Gray MJ Abstract Emerging infectious diseases are a significant threat to global biodiversity. While historically overlooked, a group of iridoviruses in the genus Ranavirus has been responsible for die-offs in captive and wild amphibian, reptile and fish populations around the globe over the past two decades. In order to share contemporary information on ranaviruses and identify critical research directions, the First International Symposium on Ranaviruses was held in July 2011 in Minneapolis, MN, USA. Twenty-three scientists and veterinarians from nine countries examined the ecology and evolution of ranavirus-host interactions, potential reservoirs, transmissi... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376898 Wed, 02 Nov 2011 04:00:00 +0100 5376898 http://www.medworm.com/index.php?rid=5376897&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22048892%26dopt%3DAbstract Authors: Pautasso M Abstract The meeting on 'Genetic Resources in the Face of New Environmental, Economic and Social Challenges' held in Montpellier (France) from 20-22 September 2011 brought together about 200 participants active in research and management of the genetic diversity of plant, animal, fungal and microbial species. Attendees had the rare opportunity to hear about agronomy, botany, microbiology, mycology, the social sciences and zoology in the same conference. The research teams presented the results of about 50 projects funded by the French Foundation for Research on Biodiversity to preserve genetic diversity carried out in Africa, Asia, Europe and the Americas. These projects aimed to better understand and manage genetic resources in a rapidly changing world (e.g. st... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376897 Wed, 02 Nov 2011 04:00:00 +0100 5376897 http://www.medworm.com/index.php?rid=5376896&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22048893%26dopt%3DAbstract Authors: White SR, Carlyle CN, Fraser LH, Cahill JF Abstract The immediate need to understand the complex responses of grasslands to climate change, to ensure food supplies and to mitigate future climate change through carbon sequestration, necessitate a global, synthesized approach. Numerous manipulative experiments have altered temperature or precipitation, often in conjunction with other interacting factors such as grazing, to understand potential effects of climate change on the ecological integrity of temperate grasslands and understand the mechanisms of change. Although the different ways in which temperature and precipitation may change to effect grasslands were well represented, variability in methodology limited generalizations. Results from these experiments were also lar... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376896 Wed, 02 Nov 2011 04:00:00 +0100 5376896 http://www.medworm.com/index.php?rid=5376907&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031720%26dopt%3DAbstract Authors: Kamino LH, Stehmann JR, Amaral S, De Marco P, Rangel TF, de Siqueira MF, De Giovanni R, Hortal J Abstract The workshop 'Species distribution models: applications, challenges and perspectives' held at Belo Horizonte (Brazil), 29-30 August 2011, aimed to review the state-of-the-art in species distribution modelling (SDM) in the neotropical realm. It brought together researchers in ecology, evolution, biogeography and conservation, with different backgrounds and research interests. The application of SDM in the megadiverse neotropics-where data on species occurrences are scarce-presents several challenges, involving acknowledging the limitations imposed by data quality, including surveys as an integral part of SDM studies, and designing the analyses in accordance with the que... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376907 Wed, 26 Oct 2011 04:00:00 +0100 5376907 http://www.medworm.com/index.php?rid=5376906&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031721%26dopt%3DAbstract Authors: Milner RN, Jennions MD, Backwell PR Abstract Courtship displays are often energetically and temporally costly as well as highly conspicuous to predators. Selection should therefore favour signalling tactics that minimize courtship costs while maintaining or increasing signal attractiveness. In fiddler crabs, males court females by waving their one greatly enlarged claw in a highly conspicuous and costly display. Here, we investigate whether courting males adjust their wave rate, and therefore the cost of courtship, to the current level of competition. We show that display rate increases as competition increases and that when competition is removed, males reduce their display rate by 30 per cent. These results suggest that male fiddler crabs actively reduce the cost of cour... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376906 Wed, 26 Oct 2011 04:00:00 +0100 5376906 http://www.medworm.com/index.php?rid=5376905&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031722%26dopt%3DAbstract Authors: Davies WI, Turton M, Peirson SN, Follett BK, Halford S, Garcia-Fernandez JM, Sharp PJ, Hankins MW, Foster RG Abstract In mammals, photoreception is restricted to cones, rods and a subset of retinal ganglion cells. By contrast, non-mammalian vertebrates possess many extraocular photoreceptors but in many cases the role of these photoreceptors and their underlying photopigments is unknown. In birds, deep brain photoreceptors have been shown to sense photic changes in daylength (photoperiod) and mediate seasonal reproduction. Nonetheless, the specific identity of the opsin photopigment 'sensor' involved has remained elusive. Previously, we showed that vertebrate ancient (VA) opsin is expressed in avian hypothalamic neurons and forms a photosensitive molecule. However, a direc... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376905 Wed, 26 Oct 2011 04:00:00 +0100 5376905 http://www.medworm.com/index.php?rid=5376904&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031723%26dopt%3DAbstract Authors: Hein AM, Keirsted KJ Abstract Understanding the effects of water temperature on the swimming performance of fishes is central in understanding how fish species will respond to global climate change. Metabolic cost of transport (COT)-a measure of the energy required to swim a given distance-is a key performance parameter linked to many aspects of fish life history. We develop a quantitative model to predict the effect of water temperature on COT. The model facilitates comparisons among species that differ in body size by incorporating the body mass-dependence of COT. Data from 22 fish species support the temperature and mass dependencies of COT predicted by our model, and demonstrate that modest differences in water temperature can result in substantial differences in the e... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376904 Wed, 26 Oct 2011 04:00:00 +0100 5376904 http://www.medworm.com/index.php?rid=5376903&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031724%26dopt%3DAbstract Authors: Kodama K, Rahman MS, Horiguchi T, Thomas P Abstract Efforts to assess the ecological impacts of the marked increase in coastal hypoxia worldwide have been hampered by a lack of biomarkers of hypoxia exposure in marine benthic organisms. Here, we show that hypoxia-inducible factor-1α (HIF-1α) transcript levels in the heart and cerebral ganglion of mantis shrimp (Oratosquilla oratoria) collected from hypoxic sites in Tokyo Bay are elevated several-fold over those in shrimp collected from normoxic sites. Upregulation of HIF-1α mRNA levels in the heart after exposure to sub-lethal hypoxia was confirmed in controlled laboratory experiments. HIF-1α transcript levels were increased at approximately threefold after 7 and 14 days of hypoxia exposure and declined to control leve... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376903 Wed, 26 Oct 2011 04:00:00 +0100 5376903 http://www.medworm.com/index.php?rid=5376902&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031725%26dopt%3DAbstract Authors: Durban JW, Pitman RL Abstract Killer whales (Orcinus orca) are important predators in high latitudes, where their ecological impact is mediated through their movements. We used satellite telemetry to provide the first evidence of migration for killer whales, characterized by fast (more than 12 km h(-1), 6.5 knots) and direct movements away from Antarctic waters by six of 12 type B killer whales tagged when foraging near the Antarctic Peninsula, including all tags transmitting for more than three weeks. Tags on five of these whales revealed consistent movements to subtropical waters (30-37° S) off Uruguay and Brazil, in surface water temperatures ranging from -1.9°C to 24.2°C; one 109 day track documented a non-stop round trip of almost 9400 km (5075 nmi) in just 42 days... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376902 Wed, 26 Oct 2011 04:00:00 +0100 5376902 http://www.medworm.com/index.php?rid=5376901&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22031726%26dopt%3DAbstract Authors: Lee MS, Worthy TH Abstract The widespread view that Archaeopteryx was a primitive (basal) bird has been recently challenged by a comprehensive phylogenetic analysis that placed Archaeopteryx with deinonychosaurian theropods. The new phylogeny suggested that typical bird flight (powered by the front limbs only) either evolved at least twice, or was lost/modified in some deinonychosaurs. However, this parsimony-based result was acknowledged to be weakly supported. Maximum-likelihood and related Bayesian methods applied to the same dataset yield a different and more orthodox result: Archaeopteryx is restored as a basal bird with bootstrap frequency of 73 per cent and posterior probability of 1. These results are consistent with a single origin of typical (forelimb-powered) bi... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376901 Wed, 26 Oct 2011 04:00:00 +0100 5376901 http://www.medworm.com/index.php?rid=5376910&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22012949%26dopt%3DAbstract Authors: Montevecchi W, Fifield D, Burke C, Garthe S, Hedd A, Rail JF, Robertson G Abstract Animal tracking provides new means to assess far-reaching environmental impacts. In the aftermath of the Deepwater Horizon explosion in the Gulf of Mexico, a long-distance migrant, the northern gannet (Morus bassanus) suffered the highest oiling among beach-wrecked birds recovered. Analysis of bird-borne tracking data indicated that 25 per cent of their North American population from multiple colonies in eastern Canada migrated to the pollution zone. Findings contrasted sharply with available mark-recapture (band recovery) data. The timing of movement into and out of the Gulf indicates that immature birds would have absorbed most oil-induced mortality. Consequently, one of two outcomes is li... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376910 Wed, 19 Oct 2011 04:00:00 +0100 5376910 http://www.medworm.com/index.php?rid=5376909&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22012950%26dopt%3DAbstract Authors: Cornelius JM, Breuner CW, Hahn TP Abstract Seasonal changes in stress steroid hormone secretions are thought to reflect investment in self-maintenance versus reproduction. The capricious conditions hypothesis (CCH) posits that reduced corticosterone (CORT) secretion during stress coincident with parental phases of breeding is necessary in harsh environments because a full response would otherwise trigger repeated nest abandonments. To test this hypothesis, we measured seasonal changes in stress physiology in free-living red crossbills (Loxia curvirostra), an opportunistically breeding songbird that regularly breeds in summer and winter. This species allows unique comparisons of breeding physiology under very different seasonal environmental conditions within locations. We ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376909 Wed, 19 Oct 2011 04:00:00 +0100 5376909 http://www.medworm.com/index.php?rid=5376908&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22012951%26dopt%3DAbstract Authors: Veresoglou SD, Rillig MC Abstract Arbuscular mycorrhizal (AM) fungi represent ubiquitous mutualists of terrestrial plants. Through the symbiosis, plant hosts, among other benefits, receive protection from pathogens. A meta-analysis was conducted on 106 articles to determine whether, following pathogen infection of AM-colonized plants, the identity of the organisms involved (pathogens, AM fungi and host plants) had implications for the extent of the AM-induced pathogen suppression. Data on fungal and nematode pathogens were analysed separately. Although we found no differences in AM effectiveness with respect to the identity of the plant pathogen, the identity of the AM isolate had a dramatic effect on the level of pathogen protection. AM efficiency differences with respect... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376908 Wed, 19 Oct 2011 04:00:00 +0100 5376908 http://www.medworm.com/index.php?rid=5376912&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21992821%26dopt%3DAbstract Authors: Townsend SW, Allen C, Manser MB Abstract Individual recognition is thought to be a crucial ability facilitating the evolution of animal societies. Given its central importance, much research has addressed the extent of this capacity across the animal kingdom. Recognition of individuals vocally has received particular attention due, in part, to the insights it provides regarding the cognitive processes that underlie this skill. While much work has focused on vocal individual recognition in primates, there is currently very little data showing comparable skills in non-primate mammals under natural conditions. This may be because non-primate mammal societies do not provide obvious contexts in which vocal individual recognition can be rigorously tested. We addressed this gap i... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376912 Wed, 12 Oct 2011 04:00:00 +0100 5376912 http://www.medworm.com/index.php?rid=5376911&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21992822%26dopt%3DAbstract Authors: Shine R, Mason RT Abstract Most reptile sex pheromones so far described are lipid molecules too large to diffuse through the air; instead, they are detected via direct contact (tongue-flicking) with another animal's body or substrate-deposited trails, using the vomeronasal system. The only non-lipid pheromone reported in snakes involves courtship termination in red-sided gartersnakes (Thamnophis sirtalis parietalis): males that encounter copulatory fluids cease courtship, presumably reflecting the futility of courting an already-mating female. Our field experiments at a communal den in Manitoba show that this pheromone can work via olfaction: courtship is terminated by exposure to airborne scents from mating conspecifics, and does not require direct contact (tongue-flickin... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5376911 Wed, 12 Oct 2011 04:00:00 +0100 5376911 http://www.medworm.com/index.php?rid=5294144&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21976624%26dopt%3DAbstract In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with fem... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5294144 Wed, 05 Oct 2011 04:00:00 +0100 5294144 http://www.medworm.com/index.php?rid=5294143&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21976625%26dopt%3DAbstract This study suggests that, like some other species, calls emitted from highly aroused individuals are less noisy. Glucocorticoids thus play an important, yet underappreciated role, in alarm call production. PMID: 21976625 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5294143 Wed, 05 Oct 2011 04:00:00 +0100 5294143 http://www.medworm.com/index.php?rid=5273050&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21957090%26dopt%3DAbstract This study investigated the dispersal of Symbiodinium spp. by the stoplight parrotfish Sparisoma viride, which had high mean densities of viable and cultivable Symbiodinium (3207-8900 cells ml(-1)) in faeces. Clades A, B and G were detected using amplified chloroplast ribosomal sequences (cp23S-HVR), and corresponded with diet preferences of fish and the environmental Symbiodinium diversity of the region. Cells are constantly dispersed in the water column and deposited in the substrate at a local level (86 ± 17.8 m(2)), demonstrating that parrotfishes are vectors for short-distance dispersal of zooxanthellae. Such dispersal could constitute a key role in the maintenance of environmental Symbiodinium reservoirs. PMID: 21957090 [PubMed - as supplied by publisher] (Source: Biology Letter... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5273050 Wed, 28 Sep 2011 04:00:00 +0100 5273050 http://www.medworm.com/index.php?rid=5273049&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21957091%26dopt%3DAbstract Authors: Huang S, Davies TJ, Gittleman JL Abstract Phylogenetic diversity (PD) represents the evolutionary history of a species assemblage and is a valuable measure of biodiversity because it captures not only species richness but potentially also genetic and functional diversity. Preserving PD could be critical for maintaining the functional integrity of the world's ecosystems, and species extinction will have a large impact on ecosystems in areas where the ecosystem cost per species extinction is high. Here, we show that impacts from global extinctions are linked to spatial location. Using a phylogeny of all mammals, we compare regional losses of PD against a model of random extinction. At regional scales, losses differ dramatically: several biodiversity hotspots in southern Asia... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5273049 Wed, 28 Sep 2011 04:00:00 +0100 5273049 http://www.medworm.com/index.php?rid=5273048&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21957092%26dopt%3DAbstract Authors: Gonda A, Välimäki K, Herczeg G, Merilä J Abstract Although the brain is known to be a very plastic organ, the effects of common ecological interactions like predation or competition on brain development have remained largely unexplored. We reared nine-spined sticklebacks (Pungitius pungitius) from two coastal marine (predation-adapted) and two isolated pond (competition-adapted) populations in a factorial experiment, manipulating perceived predatory risk and food supply to see (i) if the treatments affected brain development and (ii) if there was population differentiation in the response to treatments. We detected differences in plasticity of the bulbus olfactorius (chemosensory centre) between habitats: marine fish were not plastic, whereas pond fish had larger bulbi ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5273048 Wed, 28 Sep 2011 04:00:00 +0100 5273048 http://www.medworm.com/index.php?rid=5257395&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21937490%26dopt%3DAbstract Authors: Heide-Jørgensen MP, Laidre KL, Quakenbush LT, Citta JJ Abstract The loss of Arctic sea ice is predicted to open up the Northwest Passage, shortening shipping routes and facilitating the exchange of marine organisms between the Atlantic and the Pacific oceans. Here, we present the first observations of distribution overlap of bowhead whales (Balaena mysticetus) from the two oceans in the Northwest Passage, demonstrating this route is already connecting whales from two populations that have been assumed to be separated by sea ice. Previous satellite tracking has demonstrated that bowhead whales from West Greenland and Alaska enter the ice-infested channels of the Canadian High Arctic during summer. In August 2010, two bowhead whales from West Greenland and Alaska entered th... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5257395 Wed, 21 Sep 2011 04:00:00 +0100 5257395 http://www.medworm.com/index.php?rid=5257394&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21937491%26dopt%3DAbstract Authors: Sartori L, Xompero F, Bucchioni G, Castiello U Abstract When someone is choosing one piece from a bowl full of fruit, many pieces are within reach and visible. Although the desired piece seems to govern the particular pattern and direction of that person's reaching movement, the selection process is not impervious to the presence of task-irrelevant information (i.e. the other fruits). Evidence suggests that the kinematics of reach-to-grasp actions for a desired object integrates the motor features of all the objects which might become potential targets. Transcranial magnetic stimulation (TMS) and motor-evoked potentials (MEPs) were used by us to establish if that motor integration process can be transferred to an onlooker. Our results indicate that observation of hybrid re... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5257394 Wed, 21 Sep 2011 04:00:00 +0100 5257394 http://www.medworm.com/index.php?rid=5257393&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21937492%26dopt%3DAbstract Authors: Hoving HJ, Bush SL, Robison BH Abstract Little is known about the reproductive habits of deep-living squids. Using remotely operated vehicles in the deep waters of the Monterey Submarine Canyon, we have found evidence of mating, i.e. implanted sperm packages, on similar body locations in males and females of the rarely seen mesopelagic squid Octopoteuthis deletron. Equivalent numbers of both sexes were found to have mated, indicating that male squid routinely and indiscriminately mate with both males and females. Most squid species are short-lived, semelparous (i.e. with a single, brief reproductive period) and promiscuous. In the deep, dark habitat where O. deletron lives, potential mates are few and far between. We suggest that same-sex mating behaviour by O. deletron is... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5257393 Wed, 21 Sep 2011 04:00:00 +0100 5257393 http://www.medworm.com/index.php?rid=5257392&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21937493%26dopt%3DAbstract This study demonstrates that harmonine ((17R,9Z)-1,17-diaminooctadec-9-ene), which is present in H. axyridis haemolymph, displays broad-spectrum antimicrobial activity that includes human pathogens. Antibacterial activity is most pronounced against fast-growing mycobacteria and Mycobacterium tuberculosis, and the growth of both chloroquine-sensitive and -resistant Plasmodium falciparum strains is inhibited. Harmonine displays gametocytocidal activity, and inhibits the exflagellation of microgametocytes and zygote formation. In an Anopheles stephensi mosquito feeding model, harmonine displays transmission-blocking activity. PMID: 21937493 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5257392 Wed, 21 Sep 2011 04:00:00 +0100 5257392 http://www.medworm.com/index.php?rid=5225830&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21920955%26dopt%3DAbstract Authors: Turbill C, Smith S, Deimel C, Ruf T Abstract Ageing can progress at different rates according to an individual's physiological state. Natural hypothermia, including torpor and hibernation, is a common adaptation of small mammals to survive intermittent or seasonal declines in environmental conditions. In addition to allowing energy savings, hypothermia and torpor have been associated with retarded ageing and increased longevity. We tested the hypothesis that torpor use slows ageing by measuring changes in the relative telomere length (RTL) of Djungarian hamsters, Phodopus sungorus, a highly seasonal rodent using spontaneous daily torpor, over 180 days of exposure to a short-day photoperiod and warm (approx. 20°C) or cold (approx. 9°C) air temperatures. Multi-model infere... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5225830 Wed, 14 Sep 2011 04:00:00 +0100 5225830 http://www.medworm.com/index.php?rid=5225829&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21920956%26dopt%3DAbstract Authors: King AJ, Cheng L, Starke SD, Myatt JP Abstract Diversity of expertise at an individual level can increase intelligence at a collective level-a type of swarm intelligence (SI) popularly known as the 'wisdom of the crowd'. However, this requires independent estimates (rare in the real world owing to the availability of public information) and contradicts people's bias for copying successful individuals. To explain these inconsistencies, 429 people took part in a 'guess the number of sweets' exercise. Guesses made with no public information were diverse, resulting in highly accurate SI. Individuals with access to the previous guess, mean guess or a randomly chosen guess, tended to over-estimate the number of sweets and this undermined SI. However, when people were provided wi... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5225829 Wed, 14 Sep 2011 04:00:00 +0100 5225829 http://www.medworm.com/index.php?rid=5225828&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21920957%26dopt%3DAbstract Authors: Dufour V, Wascher CA, Braun A, Miller R, Bugnyar T Abstract Evidence for time-dependent calculations about future rewards is scarce in non-human animals. In non-human primates, only great apes are comparable with humans. Still, some species wait for several minutes to obtain a better reward in delayed exchange tasks. Corvids have been shown to match with non-human primates in some time-related tasks. Here, we investigate a delay of gratification in two corvid species, the carrion crow (Corvus corone) and the common raven (Corvus corax), in an exchange task. Results show that corvids success decreases quickly as delay increases, with a maximal delay of up to 320 s (more than 5 min). The decision to wait rests both on the quality of the prospective reward and the time requir... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5225828 Wed, 14 Sep 2011 04:00:00 +0100 5225828 http://www.medworm.com/index.php?rid=5225827&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21920958%26dopt%3DAbstract Authors: Altincicek B, Kovacs JL, Gerardo NM Abstract Carotenoids are organic pigments commonly synthesized by plants, algae and some micro-organisms. Through absorption of light energy, carotenoids facilitate photosynthesis and provide protection against photo-oxidation. While it was presumed that all carotenoids in animals were sequestered from their diets, aphids were recently shown to harbour genomic copies of functional carotenoid biosynthesis genes that were acquired via horizontal gene transfer from fungi. Our search of available animal transcripts revealed the presence of two related genes in the two-spotted spider mite Tetranychus urticae. Phylogenetic analyses suggest that the T. urticae genes were transferred from fungi into the spider mite genome, probably in a similar ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5225827 Wed, 14 Sep 2011 04:00:00 +0100 5225827 http://www.medworm.com/index.php?rid=5215733&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900310%26dopt%3DAbstract Authors: Hartkopf-Fröder C, Rust J, Wappler T, Friis EM, Viehofen A Abstract Although plant-arthropod relationships underpin the dramatic rise in diversity and ecological dominance of flowering plants and their associated arthropods, direct observations of such interactions in the fossil record are rare, as these ephemeral moments are difficult to preserve. Three-dimensionally preserved charred remains of Chloranthistemon flowers from the Late Albian to Early Cenomanian of Germany preserve scales of mosquitoes and an oribatid mite with mouthparts inserted into the pollen sac. Mosquitoes, which today are frequent nectar feeders, and the mite were feeding on pollen at the time wildfire consumed the flowers. These findings document directly arthropod feeding strategies and their role... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215733 Wed, 07 Sep 2011 04:00:00 +0100 5215733 http://www.medworm.com/index.php?rid=5215732&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900311%26dopt%3DAbstract Authors: Spottiswoode CN, Koorevaar J Abstract The most virulent avian brood parasites obligately kill host young soon after hatching, thus ensuring their monopoly of host parental care. While the host eviction behaviour of cuckoos (Cuculidae) is well documented, the host killing behaviour of honeyguide (Indicatoridae) chicks has been witnessed only once, 60 years ago, and never in situ in host nests. Here, we report from the Afrotropical greater honeyguide the first detailed observations of honeyguides killing host chicks with their specially adapted bill hooks, based on repeated video recordings (available in the electronic supplementary material). Adult greater honeyguides puncture host eggs when they lay their own, but in about half of host nests at least one host egg survived,... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215732 Wed, 07 Sep 2011 04:00:00 +0100 5215732 http://www.medworm.com/index.php?rid=5215731&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900312%26dopt%3DAbstract Authors: Hembry DH, Okamoto T, Gillespie RG Abstract Mutualisms are ubiquitous in nature, but constraints imposed by specialization may limit their ability to colonize novel environments synchronously. The ability of mutualisms to reassemble following disturbance is central to understanding their response to global change. Here, we demonstrate that a highly specialized pollination mutualism considered to be obligate (Phyllanthaceae: Glochidion; Lepidoptera: Gracillariidae: Epicephala) has colonized some of the world's most isolated archipelagoes, and we record, to our knowledge, for the first time the presence of Epicephala moths from 19 host Glochidion species on 17 islands in the Pacific Ocean. Our findings appear to offer a remarkable example of mutualism persistence in an insec... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215731 Wed, 07 Sep 2011 04:00:00 +0100 5215731 http://www.medworm.com/index.php?rid=5215730&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900313%26dopt%3DAbstract Authors: Ezard TH, Pearson PN, Aze T, Purvis A Abstract Birth-death models are central to much macroevolutionary theory. The fundamental parameters of these models concern durations. Different species concepts realize different species durations because they represent different ideas of what birth (speciation) and death (extinction) mean. Here, we use Cenozoic macroperforate planktonic foraminifera as a case study to ask: what are the dynamical consequences of changing the definition of birth and death? We show strong evidence for biotic constraints on diversification using evolutionary species, but less with morphospecies. Discussing reasons for this discrepancy, we emphasize that clarity of species concept leads to clarity of meaning when interpreting macroevolutionary birth-deat... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215730 Wed, 07 Sep 2011 04:00:00 +0100 5215730 http://www.medworm.com/index.php?rid=5215729&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900314%26dopt%3DAbstract Authors: Madsen PT, Jensen FH, Carder D, Ridgway S Abstract Delphinids produce tonal whistles shaped by vocal learning for acoustic communication. Unlike terrestrial mammals, delphinid sound production is driven by pressurized air within a complex nasal system. It is unclear how fundamental whistle contours can be maintained across a large range of hydrostatic pressures and air sac volumes. Two opposing hypotheses propose that tonal sounds arise either from tissue vibrations or through actual whistle production from vortices stabilized by resonating nasal air volumes. Here, we use a trained bottlenose dolphin whistling in air and in heliox to test these hypotheses. The fundamental frequency contours of stereotyped whistles were unaffected by the higher sound speed in heliox. Theref... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215729 Wed, 07 Sep 2011 04:00:00 +0100 5215729 http://www.medworm.com/index.php?rid=5215728&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900315%26dopt%3DAbstract Authors: Sheppard P, Sear R Abstract Despite the widespread assumption that paternal investment is substantial in our species, previous studies have shown mixed results in relation to the impact of fathers on both offspring survival and reproductive outcomes. Using data from a large representative sample of British men, we tested whether father absence is associated with the timing of reproduction-related events among boys, while controlling for various cues denoting early childhood adversity. We further tested whether the loss of the father at different childhood stages matters, so as to assess whether early life is the most important period or if effects can be seen during later childhood. The results show that father absence before age seven is associated with early reproduction... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215728 Wed, 07 Sep 2011 04:00:00 +0100 5215728 http://www.medworm.com/index.php?rid=5215727&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900316%26dopt%3DAbstract Authors: Taylor AH, Hunt GR, Gray RD Abstract Humans and chimpanzees both exhibit context-dependent tool use. That is, both species choose to use tools when food is within reach, but the context is potentially hazardous. Here, we show that New Caledonian crows used tools more frequently when food was positioned next to a novel model snake than when food was positioned next to a novel teddy bear or a familiar food bowl. However, the crows showed no significant difference in their neophobic reactions towards the teddy bear and the model snake. Therefore, the crows used tools more in response to a risky object resembling a natural predator than to a less-threatening object that provoked a comparable level of neophobia. These results show that New Caledonian crows, like humans and chim... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215727 Wed, 07 Sep 2011 04:00:00 +0100 5215727 http://www.medworm.com/index.php?rid=5215726&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21900317%26dopt%3DAbstract Authors: Russell BD, Harley CD, Wernberg T, Mieszkowska N, Widdicombe S, Hall-Spencer JM, Connell SD Abstract Most studies that forecast the ecological consequences of climate change target a single species and a single life stage. Depending on climatic impacts on other life stages and on interacting species, however, the results from simple experiments may not translate into accurate predictions of future ecological change. Research needs to move beyond simple experimental studies and environmental envelope projections for single species towards identifying where ecosystem change is likely to occur and the drivers for this change. For this to happen, we advocate research directions that (i) identify the critical species within the target ecosystem, and the life stage(s) most susce... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5215726 Wed, 07 Sep 2011 04:00:00 +0100 5215726 http://www.medworm.com/index.php?rid=5189480&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880618%26dopt%3DAbstract Authors: Arnold AS, Richards CT, Ros IG, Biewener AA PMID: 21880618 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189480 Tue, 30 Aug 2011 23:00:00 +0100 5189480 http://www.medworm.com/index.php?rid=5189479&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880619%26dopt%3DAbstract Authors: McHenry M, Summers A PMID: 21880619 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189479 Tue, 30 Aug 2011 23:00:00 +0100 5189479 http://www.medworm.com/index.php?rid=5189478&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880620%26dopt%3DAbstract Authors: Gaos AR, Lewison RL, Yañez IL, Wallace BP, Liles MJ, Nichols WJ, Baquero A, Hasbún CR, Vasquez M, Urteaga J, Seminoff JA Abstract Adult hawksbill turtles (Eretmochelys imbricata) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknow... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189478 Tue, 30 Aug 2011 23:00:00 +0100 5189478 http://www.medworm.com/index.php?rid=5189477&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880621%26dopt%3DAbstract Authors: Monclús R, Cook T, Blumstein DT Abstract The presence of male siblings in utero influences female morphology and life-history traits because testosterone transferred among foetuses may masculinize females. Similarly, litter sex composition might alter the display of sexually dimorphic behaviour, such as play and allogrooming, since they are modulated by androgens. We explored whether masculinization alters the frequency of play and sociopositive behaviour in female yellow-bellied marmots (Marmota flaviventris). We found that masculinized juvenile females were more likely to initiate play and allogrooming, but yearling females exhibited higher levels of oestrogen-modulated sociopositive behaviours. Additionally, the more they interacted, the greater number of different par... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189477 Tue, 30 Aug 2011 23:00:00 +0100 5189477 http://www.medworm.com/index.php?rid=5189476&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880622%26dopt%3DAbstract Authors: Schulte RD, Hasert B, Makus C, Michiels NK, Schulenburg H Abstract Immune responses, either constitutive or induced, are costly. An alternative defence strategy may be based on behavioural responses. For example, avoidance behaviour reduces contact with pathogens and thus the risk of infection as well as the requirement of immune system activation. Similarly, if pathogens are taken up orally, preferential feeding of pathogen-free food may be advantageous. Behavioural defences have been found in many animals, including the nematode Caenorhabditis elegans. We here tested nematodes from a laboratory based evolution experiment which had either coevolved with their microparasite Bacillus thuringiensis (BT) or evolved under control conditions. After 48 generations, coevolved pop... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189476 Tue, 30 Aug 2011 23:00:00 +0100 5189476 http://www.medworm.com/index.php?rid=5189475&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880623%26dopt%3DAbstract Authors: Crossland MR, Shine R Abstract Adaptations to suppress the viability of conspecifics may provide novel ways to control invasive taxa. The spread of cane toads (Rhinella marina) through tropical Australia has had severe ecological impacts, stimulating a search for biocontrol. Our experiments show that cane toad tadpoles produce waterborne chemical cues that suppress the viability of conspecifics encountering those cues during embryonic development. Brief (72 h) exposure to these cues in the egg and post-hatching phases massively reduced rates of survival and growth of larvae. Body sizes at metamorphosis (about three weeks later) were almost twice as great in control larvae as in tadpole-exposed larvae. The waterborne cue responsible for these effects might provide a weapon ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189475 Tue, 30 Aug 2011 23:00:00 +0100 5189475 http://www.medworm.com/index.php?rid=5189474&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880624%26dopt%3DAbstract Authors: Hampton SE, Wheeler TA Abstract Natural history as we have known it is in decline. A growing movement is emerging across disciplines, to understand its decline, and nurture its rebirth. A network of like-minded scientists, resource managers, educators, writers and artists-natural historians-recently convened four consecutive Natural History Initiative workshops to move past the forensic study of natural history, and instead focus on solutions, conspiring to identify opportunities that dovetail the practice of natural history with essential needs of modern science and society, and suggest ways forward. This series of workshops occurred at various locations in the western United States during the winter and spring of 2011, and recently culminated in a Synthesis Summit on 20-... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5189474 Tue, 30 Aug 2011 23:00:00 +0100 5189474 http://www.medworm.com/index.php?rid=5171311&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865239%26dopt%3DAbstract Authors: Foote M Abstract The distribution of species among genera and higher taxa has largely untapped potential to reveal among-clade variation in rates of origination and extinction. The probability distribution of the number of species within a genus is modelled with a stochastic, time-homogeneous birth-death model having two parameters: the rate of species extinction, μ, and the rate of genus origination, γ, each scaled as a multiple of the rate of within-genus speciation, λ. The distribution is more sensitive to γ than to μ, although μ affects the size of the largest genera. The species : genus ratio depends strongly on both γ and μ, and so is not a good diagnostic of evolutionary dynamics. The proportion of monotypic genera, however, depends mainly on γ, and so may ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171311 Tue, 23 Aug 2011 23:00:00 +0100 5171311 http://www.medworm.com/index.php?rid=5171310&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865240%26dopt%3DAbstract Authors: Lefèvre T, de Roode JC, Kacsoh BZ, Schlenke TA Abstract Hosts may defend themselves against parasitism through a wide variety of defence mechanisms, but due to finite resources, investment in one defence mechanism may trade-off with investment in another mechanism. We studied resistance strategies against the parasitoid wasp Leptopilina boulardi in two Drosophila species. We found that D. melanogaster had significantly lower physiological resistance against L. boulardi than D. simulans, and hypothesized that D. melanogaster might instead invest more heavily in other forms of defence, such as behavioural defence. We found that when given a choice between clean oviposition sites and sites infested with wasps, both D. melanogaster and D. simulans detected and avoided infeste... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171310 Tue, 23 Aug 2011 23:00:00 +0100 5171310 http://www.medworm.com/index.php?rid=5171309&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865241%26dopt%3DAbstract Authors: Roopnarine PD, Angielczyk KD Abstract The fossil record presents palaeoecological patterns of rise and fall on multiple scales of time and biological organization. Here, we argue that the rise and fall of species can result from a tragedy of the commons, wherein the pursuit of self-interests by individual agents in a larger interactive system is detrimental to the overall performance or condition of the system. Species evolving within particular communities may conform to this situation, affecting the ecological robustness of their communities. Results from a trophic network model of Permian-Triassic terrestrial communities suggest that community performance on geological timescales may in turn constrain the evolutionary opportunities and histories of the species within th... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171309 Tue, 23 Aug 2011 23:00:00 +0100 5171309 http://www.medworm.com/index.php?rid=5171308&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865242%26dopt%3DAbstract Authors: Anderson PS, Bright JA, Gill PG, Palmer C, Rayfield EJ Abstract Models are a principal tool of modern science. By definition, and in practice, models are not literal representations of reality but provide simplifications or substitutes of the events, scenarios or behaviours that are being studied or predicted. All models make assumptions, and palaeontological models in particular require additional assumptions to study unobservable events in deep time. In the case of functional analysis, the degree of missing data associated with reconstructing musculoskeletal anatomy and neuronal control in extinct organisms has, in the eyes of some scientists, rendered detailed functional analysis of fossils intractable. Such a prognosis may indeed be realized if palaeontologists attempt... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171308 Tue, 23 Aug 2011 23:00:00 +0100 5171308 http://www.medworm.com/index.php?rid=5171307&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865243%26dopt%3DAbstract Authors: Shamoun-Baranes J, van Loon EE, Purves RS, Speckmann B, Weiskopf D, Camphuysen CJ Abstract The interdisciplinary workshop 'Analysis and Visualization of Moving Objects' was held at the Lorentz Centre in Leiden, The Netherlands, from 27 June to 1 July 2011. It brought together international specialists from ecology, computer science and geographical information science actively involved in the exploration, visualization and analysis of moving objects, such as marine reptiles, mammals, birds, storms, ships, cars and pedestrians. The aim was to share expertise, methodologies, data and common questions between different fields, and to work towards making significant advances in movement research. A data challenge based on GPS tracking of lesser black-backed gulls (Larus fuscus... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171307 Tue, 23 Aug 2011 23:00:00 +0100 5171307 http://www.medworm.com/index.php?rid=5171306&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865244%26dopt%3DAbstract In this study, juvenile cleaner wrasse suffered significant costs when associated with P. rhinorhynchos mimics in terms of reduced cleaning activity. Furthermore, the costs incurred by the model increased with heightened aggression by mimics towards signal receivers. This was apparently because of behavioural changes in signal receivers, as cleaning stations with mimics that attacked frequently were visited less. Variation in the costs incurred by the model may influence mimicry accuracy and avoidance learning by the signal receiver and thus affect the overall success and maintenance of the mimicry system. PMID: 21865244 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171306 Tue, 23 Aug 2011 23:00:00 +0100 5171306 http://www.medworm.com/index.php?rid=5171305&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865245%26dopt%3DAbstract Authors: Warnock RC, Yang Z, Donoghue PC Abstract Calibration is a critical step in every molecular clock analysis but it has been the least considered. Bayesian approaches to divergence time estimation make it possible to incorporate the uncertainty in the degree to which fossil evidence approximates the true time of divergence. We explored the impact of different approaches in expressing this relationship, using arthropod phylogeny as an example for which we established novel calibrations. We demonstrate that the parameters distinguishing calibration densities have a major impact upon the prior and posterior of the divergence times, and it is critically important that users evaluate the joint prior distribution of divergence times used by their dating programmes. We illustrate a ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171305 Tue, 23 Aug 2011 23:00:00 +0100 5171305 http://www.medworm.com/index.php?rid=5171304&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865246%26dopt%3DAbstract Authors: Durant SE, Hopkins WA, Hawley DM, Hepp GR Abstract Parental effects play a vital role in shaping offspring phenotype. In birds, incubation behaviour is a critical parental effect because it influences the early developmental environment and can therefore have lifelong consequences for offspring phenotype. Recent studies that manipulated incubation temperature found effects on hatchling body composition, condition and growth, suggesting that incubation temperature could also affect energetically costly physiological processes of young birds that are important to survival (e.g. immune responses). We artificially incubated wood duck (Aix sponsa) eggs at three biologically relevant temperatures. Following incubation, we used two immunoassays to measure acquired immune response... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171304 Tue, 23 Aug 2011 23:00:00 +0100 5171304 http://www.medworm.com/index.php?rid=5171303&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21865247%26dopt%3DAbstract Authors: Noguera JC, Kim SY, Velando A Abstract Empirical evidence has shown that stressful conditions experienced during development may exert long-term negative effects on life-history traits. Although it has been suggested that oxidative stress has long-term effects, little is known about delayed consequences of oxidative stress experienced early in life in fitness-related traits. Here, we tested whether oxidative stress during development has long-term effects on a life-history trait directly related to fitness in three colonies of European shags Phalacrocorax aristotelis. Our results revealed that recruitment probability decreased with oxidative damage during the nestling period; oxidative damage, in turn, was related to the level of antioxidant capacity. Our results suggest a... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5171303 Tue, 23 Aug 2011 23:00:00 +0100 5171303 http://www.medworm.com/index.php?rid=5147427&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21849306%26dopt%3DAbstract Authors: Fitzgerald EM Abstract The titanic baleen whales (Cetacea, Mysticeti) have a bizarre skull morphology, including an elastic mandibular symphysis, which permits dynamic oral cavity expansion during bulk feeding. How this key innovation evolved from the sutured symphysis of archaeocetes has remained unclear. Now, mandibles of the Oligocene toothed mysticete Janjucetus hunderi show that basal mysticetes had an archaeocete-like sutured symphysis. This archaic morphology was paired with a wide rostrum typical of later-diverging baleen whales. This demonstrates that increased oral capacity via rostral widening preceded the evolution of mandibular innovations for filter feeding. Thus, the initial evolution of the mysticetes' unique cranial form and huge mouths was perhaps not lin... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5147427 Tue, 16 Aug 2011 23:00:00 +0100 5147427 http://www.medworm.com/index.php?rid=5147426&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21849307%26dopt%3DAbstract Authors: Domenici P, Allan B, McCormick MI, Munday PL Abstract Elevated carbon dioxide (CO(2)) has recently been shown to affect chemosensory and auditory behaviour, and activity levels of larval reef fishes, increasing their risk of predation. However, the mechanisms underlying these changes are unknown. Behavioural lateralization is an expression of brain functional asymmetries, and thus provides a unique test of the hypothesis that elevated CO(2) affects brain function in larval fishes. We tested the effect of near-future CO(2) concentrations (880 µatm) on behavioural lateralization in the reef fish, Neopomacentrus azysron. Individuals exposed to current-day or elevated CO(2) were observed in a detour test where they made repeated decisions about turning left or right. No prefe... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5147426 Tue, 16 Aug 2011 23:00:00 +0100 5147426 http://www.medworm.com/index.php?rid=5147424&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21849308%26dopt%3DAbstract Authors: Leahy SM, McCormick MI, Mitchell MD, Ferrari MC Abstract Coral reefs are currently experiencing a number of worsening anthropogenic stressors, with nearshore reefs suffering from increasing sedimentation because of growing human populations and development in coastal regions. In habitats where vision and olfaction serve as the primary sources of information, reduced visual input from suspended sediment may lead to significant alterations in prey fish behaviour. Here, we test whether prey compensate for reduced visual information by increasing their antipredator responses to chemically mediated risk cues in turbid conditions. Experiments with the spiny damselfish, Acanthochromis polyacanthus, found that baseline activity levels were reduced by 23 per cent in high turbidity ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5147424 Tue, 16 Aug 2011 23:00:00 +0100 5147424 http://www.medworm.com/index.php?rid=5147419&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21849309%26dopt%3DAbstract Authors: de Procé SM, Zeng K, Betancourt AJ, Charlesworth B Abstract We have used a polymorphism dataset on introns and coding sequences of X-linked loci in Drosophila americana to estimate the strength of selection on codon usage and/or biased gene conversion (BGC), taking into account a recent population expansion detected by a maximum-likelihood method. Drosophila americana was previously thought to have a stable demographic history, so that this evidence for a recent population expansion means that previous estimates of selection need revision. There was evidence for natural selection or BGC favouring GC over AT variants in introns, which is stronger for GC-rich than GC-poor introns. By comparing introns and coding sequences, we found evidence for selection on codon usage bias... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5147419 Tue, 16 Aug 2011 23:00:00 +0100 5147419 http://www.medworm.com/index.php?rid=5147417&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21849310%26dopt%3DAbstract Authors: Raia P, Passaro F, Fulgione D, Carotenuto F Abstract Species response to environmental change may vary from adaptation to the new conditions, to dispersal towards territories with better ecological settings (known as habitat tracking), and to extinction. A phylogenetically explicit analysis of habitat tracking in Caenozoic large mammals shows that species moving over longer distances during their existence survived longer. By partitioning the fossil record into equal time intervals, we showed that the longest distance was preferentially covered just before extinction. This supports the idea that habitat tracking is a key reaction to environmental change, and confirms that tracking causally prolongs species survival. Species covering longer distances also have morphological... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5147417 Tue, 16 Aug 2011 23:00:00 +0100 5147417 http://www.medworm.com/index.php?rid=5147414&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21849311%26dopt%3DAbstract Authors: Lihoreau M, Chittka L, Le Comber SC, Raine NE Abstract Animals collecting patchily distributed resources are faced with complex multi-location routing problems. Rather than comparing all possible routes, they often find reasonably short solutions by simply moving to the nearest unvisited resources when foraging. Here, we report the travel optimization performance of bumble-bees (Bombus terrestris) foraging in a flight cage containing six artificial flowers arranged such that movements between nearest-neighbour locations would lead to a long suboptimal route. After extensive training (80 foraging bouts and at least 640 flower visits), bees reduced their flight distances and prioritized shortest possible routes, while almost never following nearest-neighbour solutions. We di... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5147414 Tue, 16 Aug 2011 23:00:00 +0100 5147414 http://www.medworm.com/index.php?rid=5138962&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21835881%26dopt%3DAbstract We describe an enormous Late Cretaceous fossil bird from Kazakhstan, known from a pair of edentulous mandibular rami (greater than 275 mm long), which adds significantly to our knowledge of Mesozoic avian morphological and ecological diversity. A suite of autapomorphies lead us to recognize the specimen as a new taxon. Phylogenetic analysis resolves this giant bird deep within Aves as a basal member of Ornithuromorpha. This Kazakh fossil demonstrates that large body size evolved at least once outside modern birds (Neornithes) and reveals hitherto unexpected trophic diversity within Cretaceous Aves. PMID: 21835881 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5138962 Wed, 10 Aug 2011 23:00:00 +0100 5138962 http://www.medworm.com/index.php?rid=5138987&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21831880%26dopt%3DAbstract In this study, we use the newly developed technique of differential olfactory conditioning to pure, custom-designed synthetic colony odours to analyse signal discrimination in Argentine ants, Linepithema humile. Our results show that tri-methyl alkanes are more easily learned than single-methyl or straight-chain alkanes. In addition, we reveal that Argentine ants can discriminate between hydrocarbons with different branching patterns and the same chain length, but not always between hydrocarbons with the same branching patterns but different chain length. Our data thus show that biochemical characteristics influence those compounds that ants can discriminate between, and which thus potentially play a role in chemical signalling and nest-mate recognition. PMID: 21831880 [PubMed - as sup... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5138987 Tue, 09 Aug 2011 23:00:00 +0100 5138987 http://www.medworm.com/index.php?rid=5138982&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21831881%26dopt%3DAbstract Authors: Friberg U, Stewart AD, Rice WR Males and females usually invest asymmetrically in offspring. In species lacking parental care, females influence offspring in many ways, while males only contribute genetic material via their sperm. For this reason, maternal effects have long been considered an important source of phenotypic variation, while paternal effects have been presumed to be absent or negligible. The recent surge of studies showing trans-generational epigenetic effects questions this assumption, and indicates that paternal effects may be far more important than previously appreciated. Here, we test for sex-linked paternal effects in Drosophila melanogaster on a life-history trait, and find substantial support for both X- and Y-linked effects. PMID: 21831881 [PubMed -... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5138982 Tue, 09 Aug 2011 23:00:00 +0100 5138982 http://www.medworm.com/index.php?rid=5089966&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21795263%26dopt%3DAbstract Authors: Pearce E, Dunbar R Ambient light levels influence visual system size in birds and primates. Here, we argue that the same is true for humans. Light levels, in terms of both the amount of light hitting the Earth's surface and day length, decrease with increasing latitude. We demonstrate a significant positive relationship between absolute latitude and human orbital volume, an index of eyeball size. Owing to tight scaling between visual system components, this will translate into enlarged visual cortices at higher latitudes. We also show that visual acuity measured under full-daylight conditions is constant across latitudes, indicating that selection for larger visual systems has mitigated the effect of reduced ambient light levels. This provides, to our knowledge, the first supp... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5089966 Tue, 26 Jul 2011 23:00:00 +0100 5089966 http://www.medworm.com/index.php?rid=5089964&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21795264%26dopt%3DAbstract Authors: Radford AN Allogrooming occurs in a wide range of species and can serve both hygienic and social functions. While the latter have long been thought to be underpinned by reductions in tension for recipients, recent work has suggested that donors may also benefit in this way. Here, I show that, in cooperatively breeding green woodhoopoes Phoeniculus purpureus, involvement in allogrooming is followed by a reduction in self-grooming by both recipients and donors, but that the former exhibit a greater decrease. Moreover, I demonstrate for the first time that the dominance status of the allogrooming participant is important, with subordinate group members reducing subsequent self-grooming to a greater extent than the dominant pair. If avian self-directed behaviour reflects current d... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5089964 Tue, 26 Jul 2011 23:00:00 +0100 5089964 http://www.medworm.com/index.php?rid=5089963&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21795265%26dopt%3DAbstract Authors: Thomas F, Lafferty KD, Brodeur J, Elguero E, Gauthier-Clerc M, Missé D We explored associations between the common protozoan parasite Toxoplasma gondii and brain cancers in human populations. We predicted that T. gondii could increase the risk of brain cancer because it is a long-lived parasite that encysts in the brain, where it provokes inflammation and inhibits apoptosis. We used a medical geography approach based on the national incidence of brain cancers and seroprevalence of T. gondii. We corrected reports of incidence for national gross domestic product because wealth probably increases the ability to detect cancer. We also included gender, cell phone use and latitude as variables in our initial models. Prevalence of T. gondii explained 19 per cent of the residual vari... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5089963 Tue, 26 Jul 2011 23:00:00 +0100 5089963 http://www.medworm.com/index.php?rid=5089951&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21795266%26dopt%3DAbstract Authors: Wagner PJ Rate distributions are important considerations when testing hypotheses about morphological evolution or phylogeny. They also have implications about general processes underlying character evolution. Molecular systematists often assume that rates are Poisson processes with gamma distributions. However, morphological change is the product of multiple probabilistic processes and should theoretically be affected by hierarchical integration of characters. Both factors predict lognormal rate distributions. Here, a simple inverse modelling approach assesses the best single-rate, gamma and lognormal models given observed character compatibility for 115 invertebrate groups. Tests reject the single-rate model for nearly all cases. Moreover, the lognormal outperforms the gamma... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5089951 Tue, 26 Jul 2011 23:00:00 +0100 5089951 http://www.medworm.com/index.php?rid=5089976&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21775314%26dopt%3DAbstract Authors: Owens GL, Rennison DJ, Allison WT, Taylor JS The four-eyed fish, Anableps anableps, has eyes with unusual morphological adaptations for simultaneous vision above and below water. The retina, for example, is divided such that one region receives light from the aerial field and the other from the aquatic field. To understand better the adaptive value of this partitioned retina, we characterized photoreceptor distribution using in situ hybridization. Cones expressing sws1, sws2b and rh2-2 (i.e. UV, and short wavelength-sensitive) opsins were found throughout the retina, whereas cones expressing rh2-1 (middle wavelength-sensitive) were largely limited to the ventral retina and those expressing lws (long wavelength-sensitive) opsins were only expressed in the dorsal retina. We next... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5089976 Tue, 19 Jul 2011 23:00:00 +0100 5089976 http://www.medworm.com/index.php?rid=5089968&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21775315%26dopt%3DAbstract Authors: Lyson TR, Sperling EA, Heimberg AM, Gauthier JA, King BL, Peterson KJ Despite much interest in amniote systematics, the origin of turtles remains elusive. Traditional morphological phylogenetic analyses place turtles outside Diapsida-amniotes whose ancestor had two fenestrae in the temporal region of the skull (among the living forms the tuatara, lizards, birds and crocodilians)-and allied with some unfenestrate-skulled (anapsid) taxa. Nonetheless, some morphological analyses place turtles within Diapsida, allied with Lepidosauria (tuatara and lizards). Most molecular studies agree that turtles are diapsids, but rather than allying them with lepidosaurs, instead place turtles near or within Archosauria (crocodilians and birds). Thus, three basic phylogenetic positions for turt... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5089968 Tue, 19 Jul 2011 23:00:00 +0100 5089968 http://www.medworm.com/index.php?rid=5039103&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21752811%26dopt%3DAbstract Authors: Williams CT, Barnes BM, Buck CL In indigenous arctic reindeer and ptarmigan, circadian rhythms are not expressed during the constant light of summer or constant dark of winter, and it has been hypothesized that a seasonal absence of circadian rhythms is common to all vertebrate residents of polar regions. Here, we show that, while free-living arctic ground squirrels do not express circadian rhythms during the heterothermic and pre-emergent euthermic intervals of hibernation, they display entrained daily rhythms of body temperature (T(b)) throughout their active season, which includes six weeks of constant sun. In winter, ground squirrels are arrhythmic and regulate core body temperatures to within ±0.2°C for up to 18 days during steady-state torpor. In spring, after the use ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039103 Tue, 12 Jul 2011 23:00:00 +0100 5039103 http://www.medworm.com/index.php?rid=5039102&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21752812%26dopt%3DAbstract Authors: Vial F, Donnelly CA Human and livestock diseases can be difficult to control where infection persists in wildlife populations. Control of bovine tuberculosis (bTB) in British cattle is complicated by the maintenance of Mycobacterium bovis (the causative agent of bTB) in badgers, acting as reservoirs of infection. Although over 20 000 badgers were culled to control bTB between 1975 and 1997, the incidence of bTB in cattle has substantially increased in parts of Great Britain in recent decades. Our case-control study, involving 1208 cattle herds, provides further evidence of the detrimental effect of localized reactive badger culling in response to the disclosure of a confirmed bTB herd breakdown in cattle. The presence of any reactive badger culling activity and increased numbe... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039102 Tue, 12 Jul 2011 23:00:00 +0100 5039102 http://www.medworm.com/index.php?rid=5039101&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21752813%26dopt%3DAbstract Authors: Mitgutsch C, Richardson MK, Jiménez R, Martin JE, Kondrashov P, de Bakker MA, Sánchez-Villagra MR Talpid moles across all northern continents exhibit a remarkably large, sickle-like radial sesamoid bone anterior to their five digits, always coupled with a smaller tibial sesamoid bone. A possible developmental mechanism behind this phenomenon was revealed using molecular markers during limb development in the Iberian mole (Talpa occidentalis) and a shrew (Cryptotis parva), as shrews represent the closest relatives of moles but do not show these conspicuous elements. The mole's radial sesamoid develops later than true digits, as shown by Sox9, and extends into the digit area, developing in relation to an Msx2-domain at the anterior border of the digital plate. Fgf8 expression,... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039101 Tue, 12 Jul 2011 23:00:00 +0100 5039101 http://www.medworm.com/index.php?rid=5039100&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21752814%26dopt%3DAbstract Authors: Lyson TR, Bercovici A, Chester SG, Sargis EJ, Pearson D, Joyce WG Modern debate regarding the extinction of non-avian dinosaurs was ignited by the publication of the Cretaceous-Tertiary (K-T) asteroid impact theory and has seen 30 years of dispute over the position of the stratigraphically youngest in situ dinosaur. A zone devoid of dinosaur fossils reported from the last 3 m of the Upper Cretaceous, coined the '3 m gap', has helped drive controversy. Here, we report the discovery of the stratigraphically youngest in situ dinosaur specimen: a ceratopsian brow horn found in a poorly rooted, silty, mudstone floodplain deposit located no more than 13 cm below the palynologically defined boundary. The K-T boundary is identified using three criteria: (i) decrease in Cretaceous paly... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039100 Tue, 12 Jul 2011 23:00:00 +0100 5039100 http://www.medworm.com/index.php?rid=5039099&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21752815%26dopt%3DAbstract Authors: Lizé A, Doff RJ, Smaller EA, Lewis Z, Hurst GD Males in many taxa are known to exhibit behavioural plasticity in response to the perceived intensity of sperm competition, reflected in Drosophila melanogaster by increased copulation duration following prior exposure to a rival. We tested the prediction that males do not adjust their copulation effort in response to the presence of a competitor in Drosophila species where there is little or no sperm competition. Contrary to expectations, male plasticity in copulation duration was found in both Drosophila subobscura and Drosophila acanthoptera, species in which females rarely remate. These results are discussed in relation to the adaptive basis of plasticity in these species. PMID: 21752815 [PubMed - as supplied by publisher... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039099 Tue, 12 Jul 2011 23:00:00 +0100 5039099 http://www.medworm.com/index.php?rid=5039098&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21752816%26dopt%3DAbstract Authors: Leal M, Powell BJ The role of behavioural flexibility in responding to new or changing environmental challenges is a central theme in cognitive ecology. Studies of behavioural flexibility have focused mostly on mammals and birds because theory predicts that behavioural flexibility is favoured in species or clades that exploit a diversity of habitats or food sources and/or have complex social structure, attributes not associated with ectothermic vertebrates. Here, we present the results of a series of experiments designed to test cognitive abilities across multiple cognitive modules in a tropical arboreal lizard: Anolis evermanni. This lizard shows behavioural flexibility across multiple cognitive tasks, including solving a novel motor task using multiple strategies and reversa... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039098 Tue, 12 Jul 2011 23:00:00 +0100 5039098 http://www.medworm.com/index.php?rid=5039110&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733868%26dopt%3DAbstract Authors: Couchman JJ Rhesus monkeys (Macaca mulatta) have shown the ability to monitor their own mental states, but fail the mirror self-recognition test. In humans, the sense of self-agency is closely related to self-awareness, and results from monitoring the relationship between intentional, sensorimotor and perceptual information. Humans and rhesus monkeys were trained to move a computer icon with a joystick while a distractor icon partially matched their movements. Both humans and monkeys were able to monitor and identify the icon they were controlling, suggesting they have some understanding of self-agency. PMID: 21733868 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039110 Mon, 11 Jul 2011 23:00:00 +0100 5039110 http://www.medworm.com/index.php?rid=5039109&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733869%26dopt%3DAbstract Authors: Rubidge EM, Burton AC, Vamosi SM On 12-15 May 2011, a diverse group of students, researchers and practitioners from across Canada and around the world met in Banff, Alberta, to discuss the many facets of biodiversity science at the 6th Annual Meeting of the Canadian Society for Ecology and Evolution. PMID: 21733869 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039109 Tue, 05 Jul 2011 23:00:00 +0100 5039109 http://www.medworm.com/index.php?rid=5039108&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733870%26dopt%3DAbstract Authors: Scelza BA Seeking out extra-pair paternity (EPP) is a viable reproductive strategy for females in many pair-bonded species. Across human societies, women commonly engage in extra-marital affairs, suggesting this strategy may also be an important part of women's reproductive decision-making. Here, I show that among the Himba 17 per cent of all recorded marital births are attributed by women to EPP, and EPP is associated with significant increases in women's reproductive success. In contrast, there are no cases of EPP among children born into 'love match' marriages. This rate of EPP is higher than has been recorded in any other small-scale society. These results illustrate the importance of seeking EPP as a mechanism of female choice in humans, while simultaneously showing it to... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039108 Tue, 05 Jul 2011 23:00:00 +0100 5039108 http://www.medworm.com/index.php?rid=5039107&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733871%26dopt%3DAbstract Authors: Vinther J, Eibye-Jacobsen D, Harper DA The oldest annelid fossils are polychaetes from the Cambrian Period. They are representatives of the annelid stem group and thus vital in any discussion of how we polarize the evolution of the crown group. Here, we describe a fossil polychaete from the Early Cambrian Sirius Passet fauna, Pygocirrus butyricampum gen. et sp. nov., with structures identified as pygidial cirri, which are recorded for the first time from Cambrian annelids. The body is slender and has biramous parapodia with chaetae organized in laterally oriented bundles. The presence of pygidial cirri is one of the characters that hitherto has defined the annelid crown group, which diversified during the Cambrian-Ordovician transition. The newly described fossil shows that th... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039107 Tue, 05 Jul 2011 23:00:00 +0100 5039107 http://www.medworm.com/index.php?rid=5039106&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733872%26dopt%3DAbstract Authors: Clague GE, Cheney KL, Goldizen AW, McCormick MI, Waldie PA, Grutter AS Cleaning behaviour is considered to be a classical example of mutualism. However, no studies, to our knowledge, have measured the benefits to clients in terms of growth. In the longest experimental study of its kind, over an 8 year period, cleaner fish Labroides dimidiatus were consistently removed from seven patch reefs (61-285 m(2)) and left undisturbed on nine control reefs, and the growth and parasite load of the damselfish Pomacentrus moluccensis determined. After 8 years, growth was reduced and parasitic copepod abundance was higher on fish from removal reefs compared with controls, but only in larger individuals. Behavioural observations revealed that P. moluccensis cleaned by L. dimidiatus were 27 p... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039106 Tue, 05 Jul 2011 23:00:00 +0100 5039106 http://www.medworm.com/index.php?rid=5039105&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733873%26dopt%3DAbstract Authors: Schwarz S, Wystrach A, Cheng K Many animals rely on path integration for navigation and desert ants are the champions. On leaving the nest, ants continuously integrate their distance and direction of travel so that they always know their current distance and direction from the nest and can take a direct path to home. Distance information originates from a step-counter and directional information is based on a celestial compass. So far, it has been assumed that the directional information obtained from ocelli contribute to a single global path integrator, together with directional information from the dorsal rim area (DRA) of the compound eyes and distance information from the step-counter. Here, we show that ocelli mediate a distinct compass from that mediated by the compound ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039105 Tue, 05 Jul 2011 23:00:00 +0100 5039105 http://www.medworm.com/index.php?rid=5039104&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21733874%26dopt%3DAbstract Authors: Cripps JK, Wilson ME, Elgar MA, Coulson G Lactation is the most energetically expensive component of reproduction in mammals. Theory predicts that reproducing females will adjust their behaviour to compensate for increased nutritional demands. However, experimental tests are required, since comparisons of the behaviour of naturally reproducing and non-reproducing females cannot distinguish between true costs of reproduction, individual differences or seasonal variation. We experimentally manipulated reproduction in free-ranging, eastern grey kangaroos (Macropus giganteus), using a fertility control agent. Our novel field experiment revealed that females altered their behaviour in direct response to the energetic demands of reproduction: reproducing females increased bite rates... Biology Letters journals http://www.medworm.com/rss/comments.php?id=5039104 Tue, 05 Jul 2011 23:00:00 +0100 5039104 http://www.medworm.com/index.php?rid=4997098&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21715395%26dopt%3DAbstract Authors: Nguyen JM, Molak M, Black KH, Fitzgerald EM, Travouillon KJ, Ho SY The 13th Conference on Australasian Vertebrate Evolution Palaeontology and Systematics (CAVEPS) took place in Perth, Western Australia, from 27 to 30 April 2011. This biennial meeting was jointly hosted by Curtin University, the Western Australian Museum, Murdoch University and the University of Western Australia. Researchers from diverse disciplines addressed many aspects of vertebrate evolution, including functional morphology, phylogeny, ecology and extinctions. New additions to the fossil record were reported, especially from hitherto under-represented ages and clades. Yet, application of new techniques in palaeobiological analyses dominated, such as dental microwear and geochronology, and technological adv... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997098 Tue, 28 Jun 2011 23:00:00 +0100 4997098 http://www.medworm.com/index.php?rid=4997097&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21715396%26dopt%3DAbstract Authors: Duarte MH, Vecci MA, Hirsch A, Young RJ Urban areas and many natural habitats are being dominated by a new selection pressure: anthropogenic noise. The ongoing expansion of urban areas, roads and airports throughout the world makes the noise almost omnipresent. Urbanization and the increase of noise levels form a major threat to living conditions in and around cities. Insight into the behavioural strategies of urban survivors may explain the sensitivity of other species to urban selection pressures. Here, we show that urban black-tufted marmosets (Callithrix penicillata) living in noisy urban areas may select their home-range based primarily on ambient noise level. We have tested the hypothesis that the noise from vehicular traffic and visitors in an urban park in Brazil influ... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997097 Tue, 28 Jun 2011 23:00:00 +0100 4997097 http://www.medworm.com/index.php?rid=4997096&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21715397%26dopt%3DAbstract Authors: Bajer K, Molnár O, Török J, Herczeg G Animal communication through colour signals is a central theme in sexual selection. Structural colours can be just as costly and honest signals as pigment-based colours. Ultraviolet (UV) is a structural colour that can be important both in intrasexual competition and mate choice. However, it is still unknown if a UV signal alone can determine the outcome of male-male fights. European green lizard (Lacerta viridis) males develop a nuptial throat coloration with a strong UV component. Among males differing only in their manipulated UV colour, females prefer males with higher UV. Here, we experimentally decreased the UV coloration of randomly chosen males from otherwise similar male pairs to test the hypothesis that a difference in UV colo... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997096 Tue, 28 Jun 2011 23:00:00 +0100 4997096 http://www.medworm.com/index.php?rid=4997095&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21715398%26dopt%3DAbstract We examined whether, as in humans, orang-utan subjective well-being was related to longer life. The sample included 184 zoo-housed orang-utans followed up for approximately 7 years. Age, sex, species and number of transfers were available for all subjects and 172 subjects were rated on at least one item of a subjective well-being scale. Of the 31 orang-utans that died, 25 died a mean of 3.4 years after being rated. Even in a model that included, and therefore, statistically adjusted for, sex, age, species and transfers, orang-utans rated as being "happier" lived longer. The risk differential between orang-utans that were one standard deviation above and one standard deviation below baseline in subjective well-being was comparable with approximately 11 years in age. This finding suggests th... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997095 Tue, 28 Jun 2011 23:00:00 +0100 4997095 http://www.medworm.com/index.php?rid=4997103&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21697162%26dopt%3DAbstract Authors: Maure F, Brodeur J, Ponlet N, Doyon J, Firlej A, Elguero E, Thomas F Host manipulation by parasites not only captures the imagination but has important epidemiological implications. The conventional view is that parasites face a trade-off between the benefits of host manipulation and their costs to fitness-related traits, such as longevity and fecundity. However, this trade-off hypothesis remains to be tested. Dinocampus coccinellae is a common parasitic wasp of the spotted lady beetle Coleomegilla maculata. Females deposit a single egg in the haemocoel of the host, and during larval development the parasitoid feeds on host tissues. At the prepupal stage, the parasitoid egresses from its host by forcing its way through the coccinellid's abdominal segments and begins spinning a... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997103 Tue, 21 Jun 2011 23:00:00 +0100 4997103 http://www.medworm.com/index.php?rid=4997102&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21697163%26dopt%3DAbstract Authors: Benson RB, Mannion PD Statistical models are helping palaeontologists to elucidate the history of biodiversity. Sampling standardization has been extensively applied to remedy the effects of uneven sampling in large datasets of fossil invertebrates. However, many vertebrate datasets are smaller, and the issue of uneven sampling has commonly been ignored, or approached using pairwise comparisons with a numerical proxy for sampling effort. Although most authors find a strong correlation between palaeodiversity and sampling proxies, weak correlation is recorded in some datasets. This has led several authors to conclude that uneven sampling does not influence our view of vertebrate macroevolution. We demonstrate that multi-variate regression models incorporating a model of underly... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997102 Tue, 21 Jun 2011 23:00:00 +0100 4997102 http://www.medworm.com/index.php?rid=4997101&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21697164%26dopt%3DAbstract Authors: Sánchez-Macouzet O, Drummond H Despite frequent suggestions that dominance-subordination relationships in infancy can affect subsequent agonistic potential during adult life, to our knowledge no explicit test has been made. Experiments have shown that adverse conditions during early development can have long-term effects on a variety of traits ranging from growth to competitive behaviour. In many vertebrate species, the main social setting in which the infant develops is a sibling group where competition is often mediated by a dominance hierarchy. Here, we show in a long-lived marine bird that subordination to an aggressive sibling throughout infancy does not compromise aggressiveness years later during adult life. Former junior and senior chicks of the blue-footed booby, who... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997101 Tue, 21 Jun 2011 23:00:00 +0100 4997101 http://www.medworm.com/index.php?rid=4997100&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21697165%26dopt%3DAbstract Authors: Mikolasch S, Kotrschal K, Schloegl C Exclusion allows the detection of hidden food when confronted with the choice between an empty and a potentially baited food location. However, exclusion may be based on avoidance of the empty location without drawing inferences about the presence of the food in the baited location. So far, such inferences have been demonstrated in the great apes only: after seeing an experimenter eating one of two food types, which both had been hidden previously in two boxes, the apes were able to choose the box that still contained the other food type. African grey parrots are capable of exclusion, and we here assessed if they are capable of inference by exclusion. In our task, two different but equally preferred food items were hidden in full view of th... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997100 Tue, 21 Jun 2011 23:00:00 +0100 4997100 http://www.medworm.com/index.php?rid=4997099&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21697166%26dopt%3DAbstract Authors: Lee AJ, Zietsch BP When choosing a mate, women are thought to face a trade-off between genetic and parental quality. Recent research suggests that this trade-off is influenced by environmental factors such as pathogen prevalence and resource scarcity, which affect the relative value of genetic and parental quality to offspring fitness. To further investigate these findings, the current study primed 60 women with pathogen prevalence, resource scarcity or an irrelevant threat, before administering a forced trade-off task that assessed mate preferences for traits thought to be indicative of genetic or parental quality. Women primed with pathogen prevalence revealed greater preferences for traits indicative of genetic quality at the expense of traits indicative of parental quality... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997099 Tue, 21 Jun 2011 23:00:00 +0100 4997099 http://www.medworm.com/index.php?rid=4997105&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21693488%26dopt%3DAbstract Authors: Barrett PM, Benson RB, Rich TH, Vickers-Rich P A cervical vertebra from the Early Cretaceous of Victoria represents the first Australian spinosaurid theropod dinosaur. This discovery significantly extends the geographical range of spinosaurids, suggesting that the clade obtained a near-global distribution before the onset of Pangaean fragmentation. The combined presence of spinosaurid, neovenatorid, tyrannosauroid and dromaeosaurid theropods in the Australian Cretaceous undermines previous suggestions that the dinosaur fauna of this region was either largely endemic or predominantly 'Gondwanan' in composition. Many lineages are well-represented in both Laurasia and Gondwana, and these observations suggest that Early-'middle' Cretaceous theropod clades possessed more cosmopolit... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997105 Mon, 20 Jun 2011 23:00:00 +0100 4997105 http://www.medworm.com/index.php?rid=4997104&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21693489%26dopt%3DAbstract Authors: Yakob L A cryptic subgroup of Anopheles gambiae sensu stricto mosquitoes was recently discovered in West Africa. This 'GOUNDRY' subgroup has increased susceptibility to Plasmodium falciparum, the most deadly form of malaria. Unusual for this major malaria vector, GOUNDRY mosquitoes also seem to bite exclusively outdoors. A mathematical model is developed to assess the epidemiological implications of current vector control tools, bednets and indoor residual spray, preferentially suppressing the more typical indoor biting mosquitoes. It is demonstrated that even if the GOUNDRY mosquitoes have a decreased preference for human blood, vector controls which select for increased GOUNDRY abundance relative to their indoor biting counterparts risks intensifying malaria transmission. Gi... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4997104 Mon, 20 Jun 2011 23:00:00 +0100 4997104 http://www.medworm.com/index.php?rid=4947063&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21673051%26dopt%3DAbstract Authors: Sturz BR, Bodily KD PMID: 21673051 [PubMed - as supplied by publisher] (Source: Biology Letters) Biology Letters journals http://www.medworm.com/rss/comments.php?id=4947063 Mon, 13 Jun 2011 23:00:00 +0100 4947063 http://www.medworm.com/index.php?rid=4947067&cid=s_36933_62_f&fid=36933&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21653564%26dopt%3DAbstract Authors: Olszewski TD Accumulations of dead skeletal material are a valuable archive of past ecological conditions. However, such assemblages are not equivalent to living communities because they mix the remains of multiple generations and are altered by post-mortem processes. The abundance of a species in a death assemblage can be quantitatively modelled by successively integrating the product of an influx time series and a post-mortem loss function (a decay function with a constant half-life). In such a model, temporal mixing increases expected absolute dead abundance relative to average influx as a linear function of half-life and increases variation in absolute dead abundance values as a square-root function of half-life. Because typical abundance distributions of ecological commun... Biology Letters journals http://www.medworm.com/rss/comments.php?id=4947067 Thu, 09 Jun 2011 23:00:00 +0100 4947067