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Monday, 10 November 2014

What's new for 'birdRS' in PubMed: November Week 1, 2014

This message contains My NCBI what's new results from the National Center for Biotechnology Information (NCBI) at the U.S. National Library of Medicine (NLM).

PubMed Results


1. Environ Sci Technol. 2014 Nov 7. [Epub ahead of print]

Contamination of mercury during the wintering period influences concentrations at breeding sites in two migratory piscivorous birds.

Lavoie RA, Baird CJ, King LE, Kyser K, Friesen VL, Campbell L.

Abstract

Many aquatic fish-eating birds migrate long distances and are exposed to different mercury concentrations ([Hg]) during their annual cycle. Here we examined the importance of migration on [Hg] in two colonial migratory fish-eating bird species. We determined temporal trends of [Hg] and stable isotopes of carbon (δ13C) and nitrogen (δ15N) during the annual cycle in Double-crested Cormorants (Phalacrocorax auritus) and Caspian Terns (Hydroprogne caspia) breeding in Lake Ontario by a repeated sampling of breast feathers and blood from recaptured individuals. We found an effect of previous winter [Hg], species, sex and location to explain variations of Hg at breeding sites. This suggests Hg carryover from winter to summer periods and that variations of [Hg] in the summer are partially explained by [Hg] in the winter. Carryover of Hg among seasons and slow changes in [Hg] over time were found especially for individuals in high winter exposure groups, suggesting a slow depuration rate and a fast uptake rate for both species. In contrast, stable isotope values rapidly switched to reach equilibrium at a similar mid-point regardless of winter habitat or diet suggesting minimal carryover of isotopic signatures. The potential of Hg carryover from wintering sites indicates that Hg concentrations in birds at a given time may be influenced by previous exposure from distant locations.
PMID: 25380025 [PubMed - as supplied by publisher]
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2. Proc Biol Sci. 2014 Dec 22;281(1797). pii: 20141405. doi: 10.1098/rspb.2014.1405.

Trunk orientation causes asymmetries in leg function in small bird terrestrial locomotion.

Andrada E1, Rode C2, Sutedja Y2, Nyakatura JA3, Blickhan R2.
Author information:
1Science of Motion, Friedrich-Schiller University Jena, Seidelstraße 20, 07749 Jena, Germany emanuel.andrada@uni-jena.de.
2Science of Motion, Friedrich-Schiller University Jena, Seidelstraße 20, 07749 Jena, Germany.
3Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller-Universität, 07743 Jena, Germany Image Knowledge Gestaltung: an interdisciplinary laboratory and Institute of Biology, Humboldt-University, Philippstraße 13, 11015 Berlin, Germany.

Abstract

In contrast to the upright trunk in humans, trunk orientation in most birds is almost horizontal (pronograde). It is conceivable that the orientation of the heavy trunk strongly influences the dynamics of bipedal terrestrial locomotion. Here, we analyse for the first time the effects of a pronograde trunk orientation on leg function and stability during bipedal locomotion. For this, we first inferred the leg function and trunk control strategy applied by a generalized small bird during terrestrial locomotion by analysing synchronously recorded kinematic (three-dimensional X-ray videography) and kinetic (three-dimensional force measurement) quail locomotion data. Then, by simulating quail gaits using a simplistic bioinspired numerical model which made use of parameters obtained in in vivo experiments with real quail, we show that the observed asymmetric leg function (left-skewed ground reaction force and longer leg at touchdown than at lift-off) is necessary for pronograde steady-state locomotion. In addition, steady-state locomotion becomes stable for specific morphological parameters. For quail-like parameters, the most common stable solution is grounded running, a gait preferred by quail and most of the other small birds. We hypothesize that stability of bipedal locomotion is a functional demand that, depending on trunk orientation and centre of mass location, constrains basic hind limb morphology and function, such as leg length, leg stiffness and leg damping.
© 2014 The Author(s) Published by the Royal Society. All rights reserved.
PMID: 25377449 [PubMed - in process]
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3. Biol Lett. 2014 Nov;10(11). pii: 20140670. doi: 10.1098/rsbl.2014.0670.

Unexpectedly low UV-sensitivity in a bird, the budgerigar.

Chavez J1, Kelber A1, Vorobyev M1, Lind O2.
Author information:
1Department of Biology, Lund University, SE-221 00 Lund, Sweden.
2Department of Biology, Lund University, SE-221 00 Lund, Sweden olle.lind@lucs.lu.se.

Abstract

Photoreceptor adaptation ensures appropriate visual responses during changing light conditions and contributes to colour constancy. We used behavioural tests to compare UV-sensitivity of budgerigars after adaptation to UV-rich and UV-poor backgrounds. In the latter case, we found lower UV-sensitivity than expected, which could be the result of photon-shot noise corrupting cone signal robustness or nonlinear background adaptation. We suggest that nonlinear adaptation may be necessary for allowing cones to discriminate UV-rich signals, such as bird plumage colours, against UV-poor natural backgrounds.
PMID: 25376799 [PubMed - in process]
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4. Brain Behav Evol. 2014 Nov 5:214-226. [Epub ahead of print]

Anatomical Specializations for Enhanced Olfactory Sensitivity in Kiwi, Apteryx mantelli.

Corfield JR1, Eisthen HL, Iwaniuk AN, Parsons S.
Author information:
1School of Biological Sciences, University of Auckland, Auckland, New Zealand.

Abstract

The ability to function in a nocturnal and ground-dwelling niche requires a unique set of sensory specializations. The New Zealand kiwi has shifted away from vision, instead relying on auditory and tactile stimuli to function in its environment and locate prey. Behavioral evidence suggests that kiwi also rely on their sense of smell, using olfactory cues in foraging and possibly also in communication and social interactions. Anatomical studies appear to support these observations: the olfactory bulbs and tubercles have been suggested to be large in the kiwi relative to other birds, although the extent of this enlargement is poorly understood. In this study, we examine the size of the olfactory bulbs in kiwi and compare them with 55 other bird species, including emus, ostriches, rheas, tinamous, and 2 extinct species of moa (Dinornithiformes). We also examine the cytoarchitecture of the olfactory bulbs and olfactory epithelium to determine if any neural specializations beyond size are present that would increase olfactory acuity. Kiwi were a clear outlier in our analysis, with olfactory bulbs that are proportionately larger than those of any other bird in this study. Emus, close relatives of the kiwi, also had a relative enlargement of the olfactory bulbs, possibly supporting a phylogenetic link to well-developed olfaction. The olfactory bulbs in kiwi are almost in direct contact with the olfactory epithelium, which is indeed well developed and complex, with olfactory receptor cells occupying a large percentage of the epithelium. The anatomy of the kiwi olfactory system supports an enhancement for olfactory sensitivities, which is undoubtedly associated with their unique nocturnal niche. © 2014 S. Karger AG, Basel.
PMID: 25376305 [PubMed - as supplied by publisher]
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5. Oecologia. 2014 Nov 7. [Epub ahead of print]

Measuring habitat heterogeneity reveals new insights into bird community composition.

Stirnemann IA1, Ikin K, Gibbons P, Blanchard W, Lindenmayer DB.
Author information:
1Fenner School of Environment and Society, The Australian National University, Canberra, Act, 0200, Australia, ingrid.stirnemann@anu.edu.au.

Abstract

Fine-scale vegetation cover is a common variable used to explain animal occurrence, but we know less about the effects of fine-scale vegetation heterogeneity. Theoretically, fine-scale vegetation heterogeneity is an important driver of biodiversity because it captures the range of resources available in a given area. In this study we investigated how bird species richness and birds grouped by various ecological traits responded to vegetation cover and heterogeneity. We found that both fine-scale vegetation cover (of tall trees, medium-sized trees and shrubs) and heterogeneity (of tall trees, and shrubs) were important predictors of bird richness, but the direction of the response of bird richness to shrub heterogeneity differed between sites with different proportions of tall tree cover. For example, bird richness increased with shrub heterogeneity in sites with high levels of tall tree cover, but declined in sites with low levels of tall tree cover. Our findings indicated that an increase in vegetation heterogeneity will not always result in an increase in resources and niches, and associated higher species richness. We also found birds grouped by traits responded in a predictable way to vegetation heterogeneity. For example, we found small birds benefited from increased shrub heterogeneity supporting the textual discontinuity hypothesis and non-arboreal (ground or shrub) nesting species were associated with high vegetation cover (low heterogeneity). Our results indicated that focusing solely on increasing vegetation cover (e.g. through restoration) may be detrimental to particular animal groups. Findings from this investigation can help guide habitat management for different functional groups of birds.
PMID: 25376157 [PubMed - as supplied by publisher]
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6. Environ Toxicol Chem. 2014 Nov 5. doi: 10.1002/etc.2799. [Epub ahead of print]

Environmental contaminants and chromosomal damage associated with beak deformities in a resident North American passerine.

Handel CM1, Hemert CV.
Author information:
1U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA.

Abstract

A large cluster of beak abnormalities among black-capped chickadees (Poecile atricapillus) in Alaska raised concern about underlying environmental factors in this region. We analyzed metals and trace elements, organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-dioxins and polychlorinated dibenzofurans (PCDD-Fs) in adults, nestlings, and eggs of the affected population; we also tested local bird seed for OC pesticides. Our results offered no support for the hypothesis that selenium or any other inorganic element was responsible for beak deformities among chickadees, but some evidence that OC compounds may be contributing factors. Adults with beak deformities had an elevated level of chromosomal damage, which was correlated with lipid level and concentrations of several OC compounds. Multivariate analyses of pesticides and PCBs did not distinguish abnormal vs. normal adults, but subsequent univariate analysis demonstrated higher concentrations of heptachlor epoxide and PCB-123 in abnormal adults. Concentrations of all OC compounds were low and none is known to cause beak or keratin abnormalities. Patterns of PCB congener concentrations differed between nestlings with normal and abnormal parents. Eggs from clutches with low hatchability had higher concentrations of hexachlorobenzene and PCDD-Fs than those with high hatching success, and hexachlorobenzene was found in seeds. Additional testing for PCDD-Fs, polycyclic aromatic hydrocarbons, and other emerging contaminants, including brominated compounds, is needed to rule out environmental contaminants as a cause of beak deformities in chickadees in Alaska. Environ Toxicol Chem © 2014 SETAC.
© 2014 SETAC.
PMID: 25376148 [PubMed - as supplied by publisher]
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7. J Wildl Dis. 2014 Nov 6. [Epub ahead of print]

Testing for Associations between Hematozoa Infection and Mercury in Wading Bird Nestlings.

Bryan AL Jr1, Love CN, Mills GL, Borkhataria RR, Lance SL.
Author information:
11  University of Georgia-Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, South Carolina 29802, USA.

Abstract

Abstract Several wading bird species in the southeastern US have a history of infection by hematozoa/avian malaria as well as mercury accumulation through their diet, and thus may be exposed to two, generally sublethal, yet chronic, stressors. We analyzed nestling wading birds (n = 171) of varying size and trophic position from the southeastern US, and a smaller sample (n = 23) of older, free-ranging birds, to look for potential interrelationships between infection by hematozoa and mercury (Hg) uptake. Only one nestling was PCR positive for hematozoa (Plasmodium/Haemoproteus) whereas nine (39%) of the older wading birds were positive. Sequencing indicated that both nestling and adult positives were infected with Plasmodium. Given the low infection rate of the nestlings, there was no association between Hg and malaria. The older birds exhibited a possible malaria/Hg association, but it may be confounded by their greater potential exposure period and large-scale movements.
PMID: 25375937 [PubMed - as supplied by publisher]
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8. PLoS One. 2014 Nov 5;9(11):e112251. doi: 10.1371/journal.pone.0112251. eCollection 2014.

The relative impacts of climate and land-use change on conterminous United States bird species from 2001 to 2075.

Sohl TL.
Author information:
Earth Resources Observation and Science (EROS) Center, U.S. Geological Survey, Sioux Falls, South Dakota, United States of America.

Abstract

Species distribution models often use climate data to assess contemporary and/or future ranges for animal or plant species. Land use and land cover (LULC) data are important predictor variables for determining species range, yet are rarely used when modeling future distributions. In this study, maximum entropy modeling was used to construct species distribution maps for 50 North American bird species to determine relative contributions of climate and LULC for contemporary (2001) and future (2075) time periods. Species presence data were used as a dependent variable, while climate, LULC, and topographic data were used as predictor variables. Results varied by species, but in general, measures of model fit for 2001 indicated significantly poorer fit when either climate or LULC data were excluded from model simulations. Climate covariates provided a higher contribution to 2001 model results than did LULC variables, although both categories of variables strongly contributed. The area deemed to be "suitable" for 2001 species presence was strongly affected by the choice of model covariates, with significantly larger ranges predicted when LULC was excluded as a covariate. Changes in species ranges for 2075 indicate much larger overall range changes due to projected climate change than due to projected LULC change. However, the choice of study area impacted results for both current and projected model applications, with truncation of actual species ranges resulting in lower model fit scores and increased difficulty in interpreting covariate impacts on species range. Results indicate species-specific response to climate and LULC variables; however, both climate and LULC variables clearly are important for modeling both contemporary and potential future species ranges.
Free Article
PMID: 25372571 [PubMed - in process]
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9. PLoS One. 2014 Nov 5;9(11):e111696. doi: 10.1371/journal.pone.0111696. eCollection 2014.

Influence of Trichobilharzia regenti (Digenea: Schistosomatidae) on the Defence Activity of Radix lagotis (Lymnaeidae) Haemocytes.

Skála V1, Cerníková A2, Jindrová Z3, Kašný M4, Vostrý M5, Walker AJ6, Horák P1.
Author information:
1Charles University in Prague, Faculty of Science, Department of Parasitology, Prague, Czech Republic.
2Charles University in Prague, Faculty of Science, Institute of Applied Mathematics and Information Technologies, Prague, Czech Republic.
3Charles University in Prague, Faculty of Science, Department of Parasitology, Prague, Czech Republic; Charles University in Prague, 1st Faculty of Medicine, Institute of Immunology and Microbiology, Prague, Czech Republic.
4Charles University in Prague, Faculty of Science, Department of Parasitology, Prague, Czech Republic; Masaryk University, Faculty of Science, Department of Botany and Zoology, Brno, Czech Republic.
5Charles University in Prague, Faculty of Science, Department of Parasitology, Prague, Czech Republic; Institute of Haematology and Blood Transfusion, Prague, Czech Republic.
6Molecular Parasitology Laboratory, School of Life Sciences, Kingston University, Kingston upon Thames, Surrey, United Kingdom.

Abstract

Radix lagotis is an intermediate snail host of the nasal bird schistosome Trichobilharzia regenti. Changes in defence responses in infected snails that might be related to host-parasite compatibility are not known. This study therefore aimed to characterize R. lagotis haemocyte defence mechanisms and determine the extent to which they are modulated by T. regenti. Histological observations of R. lagotis infected with T. regenti revealed that early phases of infection were accompanied by haemocyte accumulation around the developing larvae 2-36 h post exposure (p.e.) to the parasite. At later time points, 44-92 h p.e., no haemocytes were observed around T. regenti. Additionally, microtubular aggregates likely corresponding to phagocytosed ciliary plates of T. regenti miracidia were observed within haemocytes by use of transmission electron microscopy. When the infection was in the patent phase, haemocyte phagocytic activity and hydrogen peroxide production were significantly reduced in infected R. lagotis when compared to uninfected counterparts, whereas haemocyte abundance increased in infected snails. At a molecular level, protein kinase C (PKC) and extracellular-signal regulated kinase (ERK) were found to play an important role in regulating these defence reactions in R. lagotis. Moreover, haemocytes from snails with patent infection displayed lower PKC and ERK activity in cell adhesion assays when compared to those from uninfected snails, which may therefore be related to the reduced defence activities of these cells. These data provide the first integrated insight into the immunobiology of R. lagotis and demonstrate modulation of haemocyte-mediated responses in patent T. regenti infected snails. Given that immunomodulation occurs during patency, interference of snail-host defence by T. regenti might be important for the sustained production and/or release of infective cercariae.
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PMID: 25372492 [PubMed - in process]
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10. Sci Rep. 2014 Nov 5;4:6923. doi: 10.1038/srep06923.

The first report of a Pelecaniformes defensin cluster: Characterization of β-defensin genes in the crested ibis based on BAC libraries.

Lan H, Chen H, Chen LC, Wang BB, Sun L, Ma MY, Fang SG, Wan QH.
Author information:
The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou 310058, P. R. China.

Abstract

Defensins play a key role in the innate immunity of various organisms. Detailed genomic studies of the defensin cluster have only been reported in a limited number of birds. Herein, we present the first characterization of defensins in a Pelecaniformes species, the crested ibis (Nipponia nippon), which is one of the most endangered birds in the world. We constructed bacterial artificial chromosome libraries, including a 4D-PCR library and a reverse-4D library, which provide at least 40 equivalents of this rare bird's genome. A cluster including 14 β-defensin loci within 129 kb was assigned to chromosome 3 by FISH, and one gene duplication of AvBD1 was found. The ibis defensin genes are characterized by multiform gene organization ranging from two to four exons through extensive exon fusion. Splicing signal variations and alternative splice variants were also found. Comparative analysis of four bird species identified one common and multiple species-specific duplications, which might be associated with high GC content. Evolutionary analysis revealed birth-and-death mode and purifying selection for avian defensin evolution, resulting in different defensin gene numbers among bird species and functional conservation within orthologous genes, respectively. Additionally, we propose various directions for further research on genetic conservation in the crested ibis.
PMID: 25372018 [PubMed - in process]
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11. Sci Rep. 2014 Nov 5;4:6920. doi: 10.1038/srep06920.

Preen secretions encode information on MHC similarity in certain sex-dyads in a monogamous seabird.

Leclaire S1, van Dongen WF2, Voccia S1, Merkling T1, Ducamp C1, Hatch SA3, Blanchard P1, Danchin E1, Wagner RH4.
Author information:
11] CNRS, UPS, ENFA; Laboratoire Évolution et Diversité Biologique (EDB), UMR5174, 118 route de Narbonne, 31062 Toulouse, France [2] Université de Toulouse, EDB, UMR5174, 31062 Toulouse, France.
21] Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna, Savoyenstrasse 1a, 1160 Vienna, Austria [2] Applied Ecology Research Group and Institute for Sustainability and Innovation, College of Engineering and Science, Victoria University - Footscray Park Campus, PO Box 14428, Melbourne MC, VIC, Australia 8001.
3U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, Alaska 99508, USA.
4Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna, Savoyenstrasse 1a, 1160 Vienna, Austria.

Abstract

Animals are known to select mates to maximize the genetic diversity of their offspring in order to achieve immunity against a broader range of pathogens. Although several bird species preferentially mate with partners that are dissimilar at the major histocompatibility complex (MHC), it remains unknown whether they can use olfactory cues to assess MHC similarity with potential partners. Here we combined gas chromatography data with genetic similarity indices based on MHC to test whether similarity in preen secretion chemicals correlated with MHC relatedness in the black-legged kittiwake (Rissa tridactyla), a species that preferentially mates with genetically dissimilar partners. We found that similarity in preen secretion chemicals was positively correlated with MHC relatedness in male-male and male-female dyads. This study provides the first evidence that preen secretion chemicals can encode information on MHC relatedness and suggests that odor-based mechanisms of MHC-related mate choice may occur in birds.
PMCID: PMC4220275 Free PMC Article
PMID: 25370306 [PubMed - in process]
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12. PLoS One. 2014 Nov 4;9(11):e112013. doi: 10.1371/journal.pone.0112013. eCollection 2014.

Gloss, colour and grip: multifunctional epidermal cell shapes in bee- and bird-pollinated flowers.

Papiorek S1, Junker RR2, Lunau K1.
Author information:
1Institute of Sensory Ecology, Department Biology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
2Department of Organismic Biology, University Salzburg, Salzburg, Austria.

Abstract

Flowers bear the function of filters supporting the attraction of pollinators as well as the deterrence of floral antagonists. The effect of epidermal cell shape on the visual display and tactile properties of flowers has been evaluated only recently. In this study we quantitatively measured epidermal cell shape, gloss and spectral reflectance of flowers pollinated by either bees or birds testing three hypotheses: The first two hypotheses imply that bee-pollinated flowers might benefit from rough surfaces on visually-active parts produced by conical epidermal cells, as they may enhance the colour signal of flowers as well as the grip on flowers for bees. In contrast, bird-pollinated flowers might benefit from flat surfaces produced by flat epidermal cells, by avoiding frequent visitation from non-pollinating bees due to a reduced colour signal, as birds do not rely on specific colour parameters while foraging. Moreover, flat petal surfaces in bird-pollinated flowers may hamper grip for bees that do not touch anthers and stigmas while consuming nectar and thus, are considered as nectar thieves. Beside this, the third hypothesis implies that those flower parts which are vulnerable to nectar robbing of bee- as well as bird-pollinated flowers benefit from flat epidermal cells, hampering grip for nectar robbing bees. Our comparative data show in fact that conical epidermal cells are restricted to visually-active parts of bee-pollinated flowers, whereas robbing-sensitive parts of bee-pollinated as well as the entire floral surface of bird-pollinated flowers possess on average flat epidermal cells. However, direct correlations between epidermal cell shape and colour parameters have not been found. Our results together with published experimental studies show that epidermal cell shape as a largely neglected flower trait might act as an important feature in pollinator attraction and avoidance of antagonists, and thus may contribute to the partitioning of flower-visitors.
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PMID: 25369510 [PubMed - in process]
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13. Proc Natl Acad Sci U S A. 2014 Nov 3. pii: 201406023. [Epub ahead of print]

Overtone-based pitch selection in hermit thrush song: Unexpected convergence with scale construction in human music.

Doolittle EL1, Gingras B2, Endres DM3, Fitch WT4.
Author information:
1 Department of Music, Cornish College of the Arts, Seattle, WA 98121;
2Department of Cognitive Biology, Faculty of Life Sciences, University of Vienna, Vienna A-1090, Austria;
3Theoretical Neuroscience Group, Philipps University of Marburg, 35032 Marburg, Germany; and Section for Computational Sensomotorics, Hertie Institute for Clinical Brain Research, Center for Integrative Neuroscience, Bernstein Center for Computational Neuroscience, and University Clinic Tübingen, 72076 Tübingen, Germany.
4Department of Cognitive Biology, Faculty of Life Sciences, University of Vienna, Vienna A-1090, Austria; tecumseh.fitch@univie.ac.at.

Abstract

Many human musical scales, including the diatonic major scale prevalent in Western music, are built partially or entirely from intervals (ratios between adjacent frequencies) corresponding to small-integer proportions drawn from the harmonic series. Scientists have long debated the extent to which principles of scale generation in human music are biologically or culturally determined. Data from animal "song" may provide new insights into this discussion. Here, by examining pitch relationships using both a simple linear regression model and a Bayesian generative model, we show that most songs of the hermit thrush (Catharus guttatus) favor simple frequency ratios derived from the harmonic (or overtone) series. Furthermore, we show that this frequency selection results not from physical constraints governing peripheral production mechanisms but from active selection at a central level. These data provide the most rigorous empirical evidence to date of a bird song that makes use of the same mathematical principles that underlie Western and many non-Western musical scales, demonstrating surprising convergence between human and animal "song cultures." Although there is no evidence that the songs of most bird species follow the overtone series, our findings add to a small but growing body of research showing that a preference for small-integer frequency ratios is not unique to humans. These findings thus have important implications for current debates about the origins of human musical systems and may call for a reevaluation of existing theories of musical consonance based on specific human vocal characteristics.
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PMID: 25368163 [PubMed - as supplied by publisher]
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14. Environ Toxicol Chem. 2014 Nov 3. doi: 10.1002/etc.2742. [Epub ahead of print]

Polybrominated diphenyl ethers in bald (Haliaeetus leucocephalus) and golden (Aquila chrysaetos) eagles from Washington and Idaho, USA.

Spears BL1, Isanhart J.
Author information:
1US Fish and Wildlife Service, Fairhope, Alabama.

Abstract

Little is known about the exposure and accumulation of polybrominated diphenyl ethers (PBDEs) in the 2 species of eagles inhabiting North America. The authors analyzed the livers of 33 bald eagles and 7 golden eagles collected throughout Washington and Idaho, USA, for 51 PBDE congeners. Total PBDEs ranged from 2.4 ng/g to 9920 ng/g wet weight. Bald eagles and eagles associated with large urban areas had the highest PBDE concentrations; golden eagles and eagles from more sparsely populated areas had the lowest concentrations. Congener patterns in the present study (brominated diphenyl ether [BDE]-47, BDE-99, BDE-100, BDE-153, and BDE-154 dominating concentrations) were similar to those reported for other bird species, especially raptors. However, the authors also found elevated contributions of BDE-209 in golden eagles and BDE-77 in both species. Patterns in bald eagle samples reflected those in fillets of fish collected from the same general locations throughout Washington, suggesting local exposure to runoff-based contamination, whereas patterns in golden eagle samples suggest a difference in food chain uptake facilitated by atmospheric transport and deposition of BDE-209 and its degradation products into the terrestrial system. Data from the present study represent some of the first reported on burdens of PBDEs in juvenile and adult eagles from North America. The high PBDE liver concentrations associated with large metropolitan areas and accumulation of deca-BDE congeners are a cause for concern. Environ Toxicol Chem 2014;9999:1-7. Published 2014 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and as such, is in the public domain in the United States of America.
Published 2014 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and as such, is in the public domain in the United States of America.
PMID: 25367115 [PubMed - as supplied by publisher]
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16. PLoS One. 2014 Nov 3;9(11):e110933. doi: 10.1371/journal.pone.0110933. eCollection 2014.

Temporal dynamics of top predators interactions in the barents sea.

Durant JM1, Skern-Mauritzen M2, Krasnov YV3, Nikolaeva NG4, Lindstrøm U5, Dolgov A6.
Author information:
1Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway.
2Institute of Marine Research, Bergen, Norway.
3Murmansk Marine Biological Institute, Murmansk, Russian Federation.
4White Sea Biological Station, Department of Biology, Lomonosov Moscow State University, Moscow, Russian Federation.
5Institute of Marine Research, Tromsø, Norway.
6Knipovich Polar Research Institute of Marine Fisheries and Oceanography (PINRO), Murmansk, Russian Federation.

Abstract

The Barents Sea system is often depicted as a simple food web in terms of number of dominant feeding links. The most conspicuous feeding link is between the Northeast Arctic cod Gadus morhua, the world's largest cod stock which is presently at a historical high level, and capelin Mallotus villosus. The system also holds diverse seabird and marine mammal communities. Previous diet studies may suggest that these top predators (cod, bird and sea mammals) compete for food particularly with respect to pelagic fish such as capelin and juvenile herring (Clupea harengus), and krill. In this paper we explored the diet of some Barents Sea top predators (cod, Black-legged kittiwake Rissa tridactyla, Common guillemot Uria aalge, and Minke whale Balaenoptera acutorostrata). We developed a GAM modelling approach to analyse the temporal variation diet composition within and between predators, to explore intra- and inter-specific interactions. The GAM models demonstrated that the seabird diet is temperature dependent while the diet of Minke whale and cod is prey dependent; Minke whale and cod diets depend on the abundance of herring and capelin, respectively. There was significant diet overlap between cod and Minke whale, and between kittiwake and guillemot. In general, the diet overlap between predators increased with changes in herring and krill abundances. The diet overlap models developed in this study may help to identify inter-specific interactions and their dynamics that potentially affect the stocks targeted by fisheries.
PMCID: PMC4218717 Free PMC Article
PMID: 25365430 [PubMed - in process]
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17. Ecol Lett. 2014 Nov 2. doi: 10.1111/ele.12387. [Epub ahead of print]

Common European birds are declining rapidly while less abundant species' numbers are rising.

Inger R1, Gregory R, Duffy JP, Stott I, Voříšek P, Gaston KJ.
Author information:
1Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK.

Abstract

Biodiversity is undergoing unprecedented global decline. Efforts to slow this rate have focused foremost on rarer species, which are at most risk of extinction. Less interest has been paid to more common species, despite their greater importance in terms of ecosystem function and service provision. How rates of decline are partitioned between common and less abundant species remains unclear. Using a 30-year data set of 144 bird species, we examined Europe-wide trends in avian abundance and biomass. Overall, avian abundance and biomass are both declining with most of this decline being attributed to more common species, while less abundant species showed an overall increase in both abundance and biomass. If overall avian declines are mainly due to reductions in a small number of common species, conservation efforts targeted at rarer species must be better matched with efforts to increase overall bird numbers, if ecological impacts of birds are to be maintained.
© 2014 John Wiley & Sons Ltd/CNRS.
PMID: 25363472 [PubMed - as supplied by publisher]
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18. Ecol Evol. 2014 Jun;4(12):2577-83. doi: 10.1002/ece3.1109. Epub 2014 May 26.

Reol: R interface to the Encyclopedia of Life.

Banbury BL, O'Meara BC.
Author information:
Department of Ecology and Evolutionary Biology, University of Tennessee Knoxville, Tennessee.

Abstract

The Encyclopedia of Life is a website that hosts information about life on Earth. Its mission is to increase awareness and understanding of living nature through a freely accessible digital source. Information is publicly available through graphical webpages (browser interface) or through an application programming interface (API). We developed Reol, an open-source package for the R environment, which downloads data from the EOL API, searches for and extracts specific information, and builds tables with quantitative data and/or hierarchical classifications. We provide a detailed description how Reol can be used as a bridge between the R environment and the EOL API to extract quantitative or hierarchical content. It will be particularly useful for researchers who want information about taxonomic groups of interest (for example: how much information is known about flatworm species? What are the taxonomic synonyms for bird species?) or construct a taxonomic tree. Reol is a tool for researchers who wish to download and gather data from EOL or its provider pages. We provide numerous functions within R for downloading, gathering data in different forms, creating taxonomic trees, and plotting data, which work with functions already available through various packages. It joins a growing body of R packages that interact with web-based APIs to streamline data acquisition, thereby easing the analysis of large publicly available datasets.
PMCID: PMC4203299 Free PMC Article
PMID: 25360287 [PubMed]
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19. Ecol Evol. 2014 Jun;4(12):2563-76. doi: 10.1002/ece3.1101. Epub 2014 May 26.

Observer aging and long-term avian survey data quality.

Farmer RG1, Leonard ML1, Mills Flemming JE2, Anderson SC3.
Author information:
1Department of Biology, Dalhousie University 1355 Oxford Street, Halifax, Nova Scotia, B3H 4R2, Canada.
2Department of Mathematics and Statistics, Dalhousie University 1355 Oxford Street, Halifax, Nova Scotia, B3H 4R2, Canada.
3Department of Biology, Dalhousie University 1355 Oxford Street, Halifax, Nova Scotia, B3H 4R2, Canada ; Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University Burnaby, British Columbia, V5A 1S6, Canada.

Abstract

Long-term wildlife monitoring involves collecting time series data, often using the same observers over multiple years. Aging-related changes to these observers may be an important, under-recognized source of error that can bias management decisions. In this study, we used data from two large, independent bird surveys, the Atlas of the Breeding Birds of Ontario ("OBBA") and the North American Breeding Bird Survey ("BBS"), to test for age-related observer effects in long-term time series of avian presence and abundance. We then considered the effect of such aging phenomena on current population trend estimates. We found significantly fewer detections among older versus younger observers for 13 of 43 OBBA species, and declines in detection as an observer ages for 4 of 6 vocalization groups comprising 59 of 64 BBS species. Consistent with hearing loss influencing this pattern, we also found evidence for increasingly severe detection declines with increasing call frequency among nine high-pitched bird species (OBBA); however, there were also detection declines at other frequencies, suggesting important additional effects of aging, independent of hearing loss. We lastly found subtle, significant relationships between some species' published population trend estimates and (1) their corresponding vocalization frequency (n ≥ 22 species) and (2) their estimated declines in detectability among older observers (n = 9 high-frequency, monotone species), suggesting that observer aging can negatively bias long-term monitoring data for some species in part through hearing loss effects. We recommend that survey designers and modelers account for observer age where possible.
PMCID: PMC4203298 Free PMC Article
PMID: 25360286 [PubMed]
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20. Ecol Evol. 2014 Jun;4(11):2239-46. doi: 10.1002/ece3.1096. Epub 2014 May 8.

Egg color variation, but not egg rejection behavior, changes in a cuckoo host breeding in the absence of brood parasitism.

Yang C1, Liu Y2, Zeng L3, Liang W1.
Author information:
1Ministry of Education Key Laboratory for Tropical Animal and Plant Ecology, College of Life Sciences, Hainan Normal University Haikou, 571158, China.
2State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University Guangzhou, 510275, China.
3Department of Biology, University of California Riverside, California, 92521, USA.

Abstract

Interactions between parasitic cuckoos and their songbird hosts form a classical reciprocal "arms race," and are an excellent model for understanding the process of coevolution. Changes in host egg coloration via the evolution of interclutch variation in egg color or intraclutch consistency in egg color are hypothesized counter adaptations that facilitate egg recognition and thus limit brood parasitism. Whether these antiparasitism strategies are maintained when the selective pressure of parasitism is relaxed remains debated. However, introduced species provide unique opportunities for testing the direction and extent of natural selection on phenotypic trait maintenance and variation. Here, we investigated egg rejection behavior and egg color polymorphism in the red-billed leiothrix (Leiothrix lutea), a common cuckoo (Cuculus canorus) host, in a population introduced to Hawaii 100 years ago (breeding without cuckoos) and a native population in China (breeding with cuckoos). We found that egg rejection ability was equally strong in both the native and the introduced populations, but levels of interclutch variation and intraclutch consistency in egg color in the native population were higher than in the introduced population. This suggests that egg rejection behavior in hosts can be maintained in the absence of brood parasitism and that egg appearance is maintained by natural selection as a counter adaptation to brood parasitism. This study provides rare evidence that host antiparasitism strategies can change under parasite-relaxed conditions and reduced selection pressure.
PMCID: PMC4201437 Free PMC Article
PMID: 25360264 [PubMed]
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