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Tuesday, 2 December 2014

What's new for 'birdRS' in PubMed: November 2014, Week 4.

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).

Sender's message: Bird research this week on PubMed

Search: (bird[TIAB] OR songbird[TIAB]) NOT (flu[TIAB] OR influenza[TIAB] OR bird[AUTH]) AND (2014/04/01[PDAT]:2020/01/01[PDAT])

View complete results in PubMed (results may change over time).

PubMed Results
Items 1 - 17 of 17

1. J Evol Biol. 2014 Nov 28. doi: 10.1111/jeb.12561. [Epub ahead of print]

Within-season increase in parental investment in a long-lived bird species: investment shifts to maximise successful reproduction?

Schneider NA1, Griesser M.
Author information:
1Department of Ecology, Swedish University of Agricultural Sciences, PO Box 7044, 75007, Uppsala, Sweden; School of Zoology, Private Bag 5, University of Tasmania, 7001, Hobart, Tasmania, Australia.

Abstract

In nest-building species predation of nest contents is a main cause of reproductive failure and parents have to trade off reproductive investment against antipredatory behaviours. While this trade-off is modified by lifespan (short-lived species prioritise current reproduction, long-lived species prioritise future reproduction), it may vary within a breeding season, but this idea has only been tested in short-lived species. Yet, life-history theory does not make any prediction how long-lived species should trade-off current against future reproductive investment within a season. Here, we investigated this trade-off through predator-exposure experiments in a long-lived bird species, the brown thornbill. We exposed breeding pairs that had no prior within-season reproductive success to the models of a nest predator and a predator of adults during their first or second breeding attempt. Overall, parents reduced their feeding rate in presence of a predator, but parents feeding second broods were more risk sensitive and almost ceased feeding when exposed to both types of predators. However, during second breeding attempts, parents had larger clutches and a higher feeding rate in absence of predators than during first breeding attempts, and approached both types of predators closer when mobbing. Our results suggest that the trade-off between reproductive investment and risk-taking can change in a long-lived species within a breeding season depending on both prior nest predation and renesting opportunities. These patterns correspond to those in short-lived species, raising the question of whether a within-season shift in reproductive investment trade-offs is independent of lifespan. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
PMID: 25430672 [PubMed - as supplied by publisher]




2. Brain Behav Evol. 2014 Nov 22. [Epub ahead of print]

Differential Expression of Melatonin Receptor Subtypes MelIa, MelIb and MelIc in Relation to Melatonin Binding in the Male Songbird Brain.

Fusani L1, Gahr M.
Author information:
1Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.

Abstract

Previous autoradiography studies illustrated that several areas of the avian brain can bind the pineal hormone melatonin. In birds, there are three melatonin receptor (MelR) subtypes: MelIa, MelIb and MelIc. To date, their brain distribution has not been studied in any passerine bird. Therefore, we investigated mRNA distribution of MelR subtypes in adjacent sections of the brain of two songbirds, the blackcap and the zebra finch, in parallel with that of 2-[125I]-iodomelatonin (IMEL) binding sites in the same brains. The general pattern of receptor expression shown by in situ hybridization of species-specific probes matched well with that of IMEL binding. However, the expression of the three subtypes was area specific with similar patterns in the two species. Some brain areas expressed only one receptor subtype, most brain regions co-expressed either MelIa with MelIb or MelIa with MelIc, whereas few areas expressed MelIb and MelIc or all three receptor subtypes. Since many sensory areas, most thalamic areas and subareas of the neopallium, a cortex analogue, express MelR, it is likely that most sensory motor integration functions are melatonin sensitive. Further, the area-specific expression patterns suggest that the regulatory role of melatonin differs among different brain areas. Since subareas of well-defined neural circuits, such as the visual system or the song control system, are equipped with different receptor types, we hypothesize a diversity of functions for melatonin in the control of sensory integration and behavior. © 2014 S. Karger AG, Basel.
PMID: 25427872 [PubMed - as supplied by publisher]
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3. BMC Vet Res. 2014 Nov 27;10(1):282. [Epub ahead of print]

Successional changes in the chicken cecal microbiome during 42 days of growth are independent of organic acid feed additives.

Oakley BB, Buhr R, Ritz CW, Kiepper BH, Berrang ME, Seal BS, Cox NA.

Abstract

BackgroundPoultry remains a major source of foodborne bacterial infections. A variety of additives with presumed anti-microbial and/or growth-promoting effects are commonly added to poultry feed during commercial grow-out, yet the effects of these additives on the gastrointestinal microbial community (the GI microbiome) as the bird matures remain largely unknown. Here we compared temporal changes in the cecal microbiome to the effects of formic acid, propionic acid, and medium-chain fatty acids (MCFA) added to feed and/or drinking water.ResultsCecal bacterial communities at day of hatch (n=5 birds), 7d (n=32), 21d (n=27), and 42d (n=36) post-hatch were surveyed using direct 454 sequencing of 16S rRNA gene amplicons from each bird in combination with cultivation-based recovery of a Salmonella Typhimurium marker strain and quantitative-PCR targeting Clostridium perfringens. Treatment effects on specific pathogens were generally non-significant. S. Typhimurium introduced by oral gavage at day of hatch was recovered by cultivation from nearly all birds sampled across treatments at 7d and 21d, but by 42d, S. Typhimurium was only recovered from ca. 25% of birds, regardless of treatment. Sequencing data also revealed non-significant treatment effects on genera containing known pathogens and on the cecal microbiome as a whole. In contrast, temporal changes in the cecal microbiome were dramatic, highly significant, and consistent across treatments. At 7d, the cecal community was dominated by three genera (Flavonifractor, Pseudoflavonifractor, and a Lachnospiracea sequence type) that accounted for more than half of sequences. By 21d post-hatch, a single genus (Faecalibacterium) accounted for 23-55% of sequences, and the number of Clostridium 16S rRNA gene copies detected by quantitative-PCR reached a maximum.ConclusionsOver the 42 d experiment, the cecal bacterial community changed significantly as measured by a variety of ecological metrics and increases in the complexity of co-occurrence networks. Management of poultry to improve animal health, nutrition, or food safety may need to consider the interactive effects of any treatments with the dramatic temporal shifts in the taxonomic composition of the cecal microbiome as described here.
Free Article
PMID: 25427406 [PubMed - as supplied by publisher]
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4. Front Zool. 2014 Nov 12;11(1):83. eCollection 2014.

Song characteristics track bill morphology along a gradient of urbanization in house finches (Haemorhous mexicanus).

Giraudeau M1, Nolan PM2, Black CE3, Earl SR4, Hasegawa M5, McGraw KJ6.
Author information:
1School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 USA ; Present address: School of Biological Sciences A08, University of Sydney, Sydney, NSW 2006 Australia.
2Department of Biology, The Citadel, Charleston, SC 29409 USA.
3Department of Biology, The College of Charleston, Charleston, SC 29424 USA.
4Global Institute of Sustainability & School of Sustainability, Arizona State University, Tempe, AZ 85287-5402 USA.
5Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba-shi, Ibaraki 305-8572 Japan.
6School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 USA.

Abstract

INTRODUCTION:

Urbanization can considerably impact animal ecology, evolution, and behavior. Among the new conditions that animals experience in cities is anthropogenic noise, which can limit the sound space available for animals to communicate using acoustic signals. Some urban bird species increase their song frequencies so that they can be heard above low-frequency background city noise. However, the ability to make such song modifications may be constrained by several morphological factors, including bill gape, size, and shape, thereby limiting the degree to which certain species can vocally adapt to urban settings. We examined the relationship between song characteristics and bill morphology in a species (the house finch, Haemorhous mexicanus) where both vocal performance and bill size are known to differ between city and rural animals.

RESULTS:

We found that bills were longer and narrower in more disturbed, urban areas. We observed an increase in minimum song frequency of urban birds, and we also found that the upper frequency limit of songs decreased in direct relation to bill morphology.

CONCLUSIONS:

These findings are consistent with the hypothesis that birds with longer beaks and therefore longer vocal tracts sing songs with lower maximum frequencies because longer tubes have lower-frequency resonances. Thus, for the first time, we reveal dual constraints (one biotic, one abiotic) on the song frequency range of urban animals. Urban foraging pressures may additionally interact with the acoustic environment to shape bill traits and vocal performance.
PMCID: PMC4243808 Free PMC Article
PMID: 25426158 [PubMed - as supplied by publisher]
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5. J Comp Neurol. 2014 Nov 26. doi: 10.1002/cne.23719. [Epub ahead of print]

Convergent differential regulation of SLIT-ROBO axon guidance genes in the brains of vocal learners.

Wang R1, Chen CC, Hara E, Rivas MV, Roulhac PL, Howard JT, Chakraborty M, Audet JN, Jarvis ED.
Author information:
1Department of Neurobiology, Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC, 27710, USA; Computational Biology and Bioinformatics Program, Institute for Genome Science and Policy, Duke University, Durham, NC, 27710, USA; Beijing Prosperous Biopharm Co., Ltd., Beijing, 100085, China.

Abstract

Only a few distantly related mammals and birds have the trait of complex vocal learning, which is the ability to imitate novel sounds. This ability is critical for speech acquisition and production in humans, and is attributed to specialized forebrain vocal control circuits that have several unique connections relative to adjacent brain circuits. As a result, it has been hypothesized that there could exist convergent changes in genes involved in neural connectivity of vocal learning circuits. In support of this hypothesis, expanding upon a companion study (Pfenning et al., 2014), here we show that the forebrain part of this circuit that makes a relatively rare direct connection to brainstem vocal motor neurons in independent lineages of vocal learning birds (songbird, parrot, and hummingbird) has specialized regulation of axon guidance genes from the SLIT-ROBO molecular pathway. The SLIT1 ligand was differentially down-regulated in the motor song output nucleus that makes the direct projection, whereas its receptor ROBO1 was developmentally upregulated during critical periods for vocal learning. Vocal non-learning bird species and male mice, which have much more limited vocal plasticity and associated circuits, did not show comparable specialized regulation of SLIT-ROBO genes in their non-vocal motor cortical regions. These findings are consistent with SLIT and ROBO gene dysfunctions associated with autism, dyslexia, and speech sound language disorders and suggest that convergent evolution of vocal learning was associated with convergent changes in the SLIT-ROBO axon guidance pathway. This article is protected by copyright. All rights reserved.
Copyright © 2014 Wiley Periodicals, Inc., A Wiley Company.
PMID: 25424606 [PubMed - as supplied by publisher]
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6. Oecologia. 2014 Nov 26. [Epub ahead of print]

Higher reproductive success of small males and greater recruitment of large females may explain strong reversed sexual dimorphism (RSD) in the northern goshawk.

Pérez-Camacho L1, García-Salgado G, Rebollo S, Martínez-Hesterkamp S, Fernández-Pereira JM.
Author information:
1Ecology and Forest Restoration Group, Department of Life Sciences, University of Alcalá, Sciences Building, 28805, Alcalá de Henares, Madrid, Spain, lorenzo.perez@uah.es.

Abstract

Reversed sexual dimorphism (RSD), which occurs when the female of a species is larger than the male, is the rule for most birds of prey but the exception among other bird and mammal species. The selective pressures that favour RSD are an intriguing issue in animal ecology. Despite the large number of hypotheses proposed to explain the evolution of RSD, there is still no consensus about the mechanisms involved and whether they act on one or both sexes, mainly because few intrapopulation studies have been undertaken and few raptor species have been investigated. Using the strongly size-dimorphic northern goshawk (Accipiter gentilis L.) as a model, we studied a population with one of the highest densities of breeding pairs reported in the literature in order to understand selective pressures that may favour RSD. We evaluated life-history processes, including recruitment of adult breeders and reproductive success, and we explored the mechanisms thought to act on each sex, including hunting efficiency, diet, body condition and mate choice. We found that smaller males produced more fledglings than larger ones, but there was no relationship between size and reproductive success for females. The mean body size of female breeders was larger than that of female fledglings, but male fledglings and breeders did not differ in size. Male body size was related to the type but not to the amount of prey captured during the nestling stage. We conclude that RSD may be favoured in this goshawk population because small males tend to enjoy higher reproductive success and large females greater recruitment. Our results do not support the hypotheses that evolutionary reduction in male size is driven by hunting efficiency, at least during the nestling stage, or the hypotheses that it is driven by greater recruitment. Our findings also suggest that increase in female size is driven by recruitment, rather than by reproductive success as previously postulated.
PMID: 25424156 [PubMed - as supplied by publisher]
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7. Plant Biol (Stuttg). 2014 Nov 25. doi: 10.1111/plb.12253. [Epub ahead of print]

Heterogeneity in soil water and light environments and dispersal limitation: what facilitates tree species coexistence in a temperate forest?

Masaki T1, Hata S, Ide Y.
Author information:
1Forestry and Forest Products Research Institute, Ibaraki, Japan.

Abstract

In the present study, we analysed the habitat association of tree species in an old-growth temperate forest across all life stages to test theories on the coexistence of tree species in forest communities. An inventory for trees was implemented at a 6-ha plot in Ogawa Forest Reserve for adults, juveniles, saplings and seedlings. Volumetric soil water content (SMC) and light levels were measured in 10-m grids. Relationships between the actual number of stems and environmental variables were determined for 35 major tree species, and the spatial correlations within and among species were analysed. The light level had no statistically significant effect on distribution of saplings and seedlings of any species. In contrast, most species had specific optimal values along the SMC gradient. The optimal values were almost identical in earlier life stages, but were more variable in later life stages among species. However, no effective niche partitioning among the species was apparent even at the adult stage. Furthermore, results of spatial analyses suggest that dispersal limitation was not sufficient to mitigate competition between species. This might result from well-scattered seed distribution via wind and bird dispersal, as well as conspecific density-dependent mortality of seeds and seedlings. Thus, both niche partitioning and dispersal limitation appeared less important for facilitating coexistence of species within this forest than expected in tropical forests. The tree species assembly in this temperate forest might be controlled through a neutral process at the spatial scale tested in this study.
© 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.
PMID: 25424149 [PubMed - as supplied by publisher]




8. Nurs Stand. 2014 Nov 26;29(13):27. doi: 10.7748/ns.29.13.27.s31.

Bird brained.

Newnham D.

Abstract

A friend has just sent me a cutting from the paper. 'Chickens helping the elderly tackle loneliness,' it says. Is he trying to tell me something?
PMID: 25424092 [PubMed - in process]




9. Environ Manage. 2014 Nov 25. [Epub ahead of print]

Identifying Common Patterns in Diverse Systems: Effects of Exurban Development on Birds of the Adirondack Park and the Greater Yellowstone Ecosystem, USA.

Glennon MJ1, Kretser HE, Hilty JA.
Author information:
1Wildlife Conservation Society, 132 Bloomingdale Ave, Saranac Lake, NY, 12983, USA, mglennon@wcs.org.

Abstract

We examined the impacts of exurban development on bird communities in Essex County, New York and Madison County, Montana by comparing differences in abundance of songbirds between subdivisions and control sites in both regions. We hypothesized that impacts to bird communities would be greater in the relatively homogeneous, closed canopy Adirondack forest of northern New York State than they would be in the more naturally heterogeneous grasslands interspersed with trees and shrubs of the Greater Yellowstone Ecosystem. We examined birds in five functional groups expected to be responsive to exurban development, and determined relative abundance within subdivisions and control sites across these two distinct regions. We found little support for our hypothesis. For birds in the area-sensitive, low nesting, and Neotropical migrant functional groups, relative abundance was lower in subdivisions in the Adirondacks and in Madison County, while relative abundance of edge specialists was greater in subdivisions in both regions. The direction and magnitude of change in the avian communities between subdivisions and controls was similar in both regions for all guilds except microhabitat specialists. These similarities across diverse ecosystems suggest that the ecological context of the encompassing region may be less important than other elements in shaping avian communities in exurban systems. This finding suggests that humans and their specific behaviors and activities in exurban areas may be underappreciated but potentially important drivers of change in these regions.
PMID: 25421994 [PubMed - as supplied by publisher]
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10. BMC Genet. 2014 Nov 25;15(1):117. [Epub ahead of print]

Genome-wide candidate regions for selective sweeps revealed through massive parallel sequencing of DNA across ten turkey populations.

Aslam ML, Bastiaansen J, Megens HJ, Crooijmans R, Nasreen F, Blomberg L, Van Tassell CP, Sonstegard TS, Schroeder SG, Groenen M, Long JA.

Abstract

BackgroundThe domestic turkey (Meleagris gallopavo) is an important agricultural species that is largely used as a meat-type bird. Characterizing genetic variation in populations of domesticated species and associating these variation patterns with the evolution, domestication, and selective breeding is critical for understanding the dynamics of genomic change in these species. Intense selective breeding and population bottlenecks are expected to leave signatures in the genome of domesticated species, such as unusually low nucleotide diversity or the presence of exceptionally extended haplotype homozygosity. These patterns of variation in selected populations are highly useful to not only understand the consequences of selective breeding and population dynamics, but also to provide insights into biological mechanisms that may affect physiological processes important to bring changes in phenotype of interest.ResultsWe observed 54 genomic regions in heritage and commercial turkey populations on 14 different chromosomes that showed statistically significant (P¿<¿0.05) reduction in genomic variation indicating candidate selective sweeps. Areas with evidence of selective sweeps varied from 1.5 Mb to 13.8 Mb in length. Out of these 54 sweeps, 23 overlapped at least partially between two or more populations. Overlapping sweeps were found on 13 different chromosomes. The remaining 31 sweeps were population-specific and were observed on 12 different chromosomes, with 26 of these regions present only in commercial populations. Genes that are known to affect growth were enriched in the sweep regions.ConclusionThe turkey genome showed large sweep regions. The relatively high number of sweep regions in commercial turkey populations compared to heritage varieties and the enrichment of genes important to growth in these regions, suggest that these sweeps are the result of intense selection in these commercial lines, moving specific haplotypes towards fixation.
Free Article
PMID: 25421611 [PubMed - as supplied by publisher]
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11. Oecologia. 2014 Nov 25. [Epub ahead of print]

Accumulation of dietary carotenoids, retinoids and tocopherol in the internal tissues of a bird: a hypothesis for the cost of producing colored ornaments.

García-de Blas E1, Mateo R, Alonso-Alvarez C.
Author information:
1Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo s/n, 13071, Ciudad Real, Spain, esther.garciablas@uclm.es.

Abstract

Carotenoid-based ornaments may have evolved as a consequence of their costs of production, which would assure the reliability of the traits as signals of individual quality. Different costs due to carotenoid allocation to the signal have been proposed, considering the scarcity of these pigments at the environment (ecological cost) and their physiological properties that would trade against the maintenance of the organism. Carotenoids of many red ornaments (ketocarotenoids) are often the result of biotransformation of those pigments abundant in the diet (usually lutein and zeaxanthin). Some authors have suggested that such a conversion implies a cost relevant for signaling because it requires high levels of antioxidant vitamins in the tissues where biotransformation takes place. We explore this hypothesis in red-legged partridges (Alectoris rufa) by analyzing ketocarotenoids in the ornaments (bare parts) and carotenoids, vitamin A in different forms (free and esterified) and vitamin E in blood, liver and fat. Ketocarotenoids in ornaments (astaxanthin and papilioerythrinone) were not found in internal tissues, suggesting that they were directly transformed in the bare parts. However, ketocarotenoid levels where positively correlated with the levels of their precursors (zeaxanthin and lutein, respectively) in internal tissues. Interestingly, ketocarotenoid levels in bare parts negatively and positively correlated with vitamin A and E in the liver, respectively, the same links only being positive in blood. Moreover, retinyl and zeaxanthin levels in liver were negatively related. We hypothesize that storing substrate carotenoids in the main storage site (the liver) implies a cost in terms of regulating the level of vitamin A.
PMID: 25421097 [PubMed - as supplied by publisher]
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12. PLoS One. 2014 Nov 24;9(11):e112657. doi: 10.1371/journal.pone.0112657. eCollection 2014.

A new species of muscicapa flycatcher from sulawesi, indonesia.

Harris JB1, Rasmussen PC2, Yong DL3, Prawiradilaga DM4, Putra DD5, Round PD6, Rheindt FE7.
Author information:
1Environment Institute and School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia; Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, New Jersey, United States of America.
2Michigan State University Museum and Department of Integrative Biology, East Lansing, Michigan, United States of America; Bird Group, Department of Life Sciences, Natural History Museum at Tring, Tring, Herts, United Kingdom.
3Fenner School of Environment and Society, Australian National University, Acton, Australian Capital Territory, Australia; South-east Asian Biodiversity Society, Singapore, Republic of Singapore.
4Division of Zoology, Research Centre for Biology, Lembaga Ilmu Pengetahuan Indonesia, Cibinong-Bogor, West Java, Indonesia.
5Celebes Bird Club, Palu, Central Sulawesi, Indonesia.
6Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand.
7Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore.

Abstract

The Indonesian island of Sulawesi, a globally important hotspot of avian endemism, has been relatively poorly studied ornithologically, to the extent that several new bird species from the region have been described to science only recently, and others have been observed and photographed, but never before collected or named to science. One of these is a new species of Muscicapa flycatcher that has been observed on several occasions since 1997. We collected two specimens in Central Sulawesi in 2012, and based on a combination of morphological, vocal and genetic characters, we describe the new species herein, more than 15 years after the first observations. The new species is superficially similar to the highly migratory, boreal-breeding Gray-streaked Flycatcher Muscicapa griseisticta, which winters in Sulawesi; however, the new species differs strongly from M. griseisticta in several morphological characters, song, and mtDNA. Based on mtDNA, the new species is only distantly related to M. griseisticta, instead being a member of the M. dauurica clade. The new species is evidently widely distributed in lowland and submontane forest throughout Sulawesi. This wide distribution coupled with the species' apparent tolerance of disturbed habitats suggests it is not currently threatened with extinction.
PMCID: PMC4242539 Free PMC Article
PMID: 25419968 [PubMed - in process]
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13. PLoS One. 2014 Nov 24;9(11):e113844. doi: 10.1371/journal.pone.0113844. eCollection 2014.

ENSO, Nest Predation Risk, Food Abundance, and Male Status Fail to Explain Annual Variations in the Apparent Survival Rate of a Migratory Songbird.

Vernouillet A1, Villard MA1, Haché S2.
Author information:
1Département de biologie, Université de Moncton, Moncton, Canada.
2 Department of Biological Sciences, University of Alberta, Edmonton, Canada.

Abstract

Adult mortality can be a major driver of population decline in species whose productivity is relatively low. Yet, little is known about the factors influencing adult survival rates in migratory bird species, nor do we know much about the longer-term effects of habitat disturbance on the fitness of individuals. The Ovenbird (Seiurus aurocapilla) is one of the vertebrate species most sensitive to forest management, yet it is still common and widespread. We monitored the fate of 330 colour-banded Ovenbird males in four pairs of 25-ha plots during 9 successive breeding seasons. One plot of each pair was treated through selection harvesting (30-40% basal area removed) during the first winter. We tested the following hypotheses: (1) higher physiological costs in harvested plots as a result of lower food abundance will reduce apparent survival rate (ASR) relative to controls; (2) lower ASR following years with low nest survival and higher probability of renesting; (3) fluctuations in ASR reflecting El Niño Southern Oscillation (ENSO); and (4) higher ASR in returning males than in recruits (unbanded immigrants) owing to greater site familiarity in the former. We tested the relative importance of these hypotheses, or combinations thereof, by generating 23 models explaining variation in ASR. The year-dependent model received the most support, showing a 41% decrease in ASR from 2007 to 2014. The important year-to-year variation we observed in ASR (Σwi = 0.99) was not explained by variation in nest predation risk nor by ENSO. There was also little evidence for an effect of selection harvesting on ASR of Ovenbird males, despite a slight reduction in lifespan relative to males from control plots (2.7 vs 2.9 years). An avenue worth exploring to explain this intriguing pattern would be to determine whether conditions at migratory stopover sites or in the wintering area of our focal population have gradually worsened over the past decade.
PMCID: PMC4242669 Free PMC Article
PMID: 25419839 [PubMed - in process]
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14. Behav Ecol. 2014 Nov;25(6):1436-1450. Epub 2014 Aug 25.

Negotiation of territorial boundaries in a songbird.

Vehrencamp SL1, Ellis JM2, Cropp BF3, Koltz JM1.
Author information:
1Lab of Ornithology and Department of Neurobiology and Behavior, Mudd Hall, 215 Tower Road, Cornell University , Ithaca, NY 14853 , USA .
2Department of Integrative Biology and Physiology, Terasaki Life Sciences Bldg, 610 Charles E. Young East, University of California Los Angeles , Los Angeles, CA 90095 , USA , and.
3Division of Health Sciences Informatics, 2024 East Monument Street, Suite 1-200, Johns Hopkins School of Medicine , Baltimore, MD 21205 , USA.

Abstract

How do territorial neighbors resolve the location of their boundaries? We addressed this question by testing the predictions of 2 nonexclusive game theoretical models for competitive signaling: the sequential assessment game and the territorial bargaining game. Our study species, the banded wren, is a neotropical nonmigratory songbird living in densely packed territorial neighborhoods. The males possess repertoires of approximately 25 song types that are largely shared between neighbors and sequentially delivered with variable switching rates. Over 3 days, boundary disputes among pairs of neighboring males were synchronously recorded, their perch positions were marked, and their behavioral interactions were noted. For each countersinging interaction between 2 focal males, we quantified approach and retreat order, a variety of song and call patterns, closest approach distance, distance from the territorial center, and female presence. Aggressors produced more rattle-buzz songs during the approaching phase of interactions, whereas defenders overlapped their opponent's songs. During the close phase of the interaction, both males matched frequently, but the key determinant of which one retreated first was song-type diversity-first retreaters sang with a higher diversity. Retreaters also produced more unshared song types during the interaction, and in the retreating phase of the interaction, they overlapped more. A negative correlation between song-type diversity asymmetry and contest duration suggested sequential assessment of motivational asymmetry. The use of this graded signal, which varied with distance from the center and indicated a male's motivation to defend a particular position, supported the bargaining model. The bargaining game could be viewed as a series of sequential assessment contests.
PMCID: PMC4235583 [Available on 2015/11/1]
PMID: 25419086 [PubMed]




15. Bioinspir Biomim. 2014 Nov 24;9(4):046017. doi: 10.1088/1748-3182/9/4/046017.

A lifting line model to investigate the influence of tip feathers on wing performance.

Fluck M1, Crawford C.
Author information:
1Department of Mechanical Engineering, Institute for Integrated Energy Systems (IESVic), University of Victoria,Victoria, BC V8W 2Y2, Canada.

Abstract

Bird wings have been studied as prototypes for wing design since the beginning of aviation. Although wing tip slots, i.e. wings with distinct gaps between the tip feathers (primaries), are very common in many birds, only a few studies have been conducted on the benefits of tip feathers on the wing's performance, and the aerodynamics behind tip feathers remains to be understood. Consequently most aircraft do not yet copy this feature. To close this knowledge gap an extended lifting line model was created to calculate the lift distribution and drag of wings with tip feathers. With this model, is was easily possible to combine several lifting surfaces into various different birdwing-like configurations. By including viscous drag effects, good agreement with an experimental tip slotted reference case was achieved. Implemented in C++ this model resulted in computation times of less than one minute per wing configuration on a standard notebook computer. Thus it was possible to analyse the performance of over 100 different wing configurations with and without tip feathers. While generally an increase in wing efficiency was obtained by splitting a wing tip into distinct, feather-like winglets, the best performance was generally found when spreading more feathers over a larger dihedral angle out of the wing plane. However, as the results were very sensitive to the precise geometry of the feather fan (especially feather twist) a careless set-up could just as easily degrade performance. Hence a detailed optimization is recommended to realize the full benefits by simultaneously optimizing feather sweep, twist and dihedral angles.
PMID: 25418986 [PubMed - in process]
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16. Mol Ecol Resour. 2014 Nov 22. doi: 10.1111/1755-0998.12344. [Epub ahead of print]

Barcoding Neotropical birds: assessing the impact of non-monophyly in a highly diverse group.

Chaves BR1, Chaves AV, Nascimento AC, Chevitarese J, Vasconcelos MF, Santos FR.
Author information:
1Laboratório de Biodiversidade e Evolução Molecular, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6627, Instituto de Ciências Biológicas, Bloco L3, Sala 244. CEP, 31270-901, Belo Horizonte, Minas Gerais, Brazil.

Abstract

In this study, we verified the power of DNA barcodes to discriminate Neotropical birds using Bayesian tree reconstructions of a total of 7,404 COI sequences from 1,521 species, including 55 Brazilian species with no previous barcode data. We found that 10.4% of species were non-monophyletic, most likely due to inaccurate taxonomy, incomplete lineage sorting, or hybridization. At least 0.5% of the sequences (2.5% of the sampled species) retrieved from GenBank were associated with database errors (poor quality sequences, NuMTs, misidentification or unnoticed hybridization). Paraphyletic species (5.8% of the total) can be related to rapid speciation events leading to non-reciprocal monophyly between recently diverged sister species, or to absence of synapormorphies in the small COI region analysed. We also performed two series of genetic distance calculations under the K2P model for intraspecific and interspecific comparisons: the first included all COI sequences, and the second included only monophyletic taxa observed in the Bayesian trees. As expected, the mean and median pairwise distances were smaller for intraspecific than for interspecific comparisons. However, there was no precise "barcode gap", which was shown to be larger in the monophyletic taxon dataset than for the data from all species, as expected. Our results indicated that although database errors may explain some of the difficulties in the species discrimination of Neotropical birds, distance-based barcode assignment may also be compromised because of the high diversity of bird species and more complex speciation events in the Neotropics. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
PMID: 25417731 [PubMed - as supplied by publisher]




17. Cell Mol Life Sci. 2014 Nov 22. [Epub ahead of print]

Detecting the emergence of novel, zoonotic viruses pathogenic to humans.

Rosenberg R.
Author information:
Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Rampart Road, Fort Collins, CO, 80521, USA, viruslist@cdc.gov.

Abstract

RNA viruses, with their high potential for mutation and epidemic spread, are the most common class of pathogens found as new causes of human illness. Despite great advances made in diagnostic technology since the 1950s, the annual rate at which novel virulent viruses have been found has remained at 2-3. Most emerging viruses are zoonoses; they have jumped from mammal or bird hosts to humans. An analysis of virus discovery indicates that the small number of novel viruses discovered annually is an artifact of inadequate surveillance in tropical and subtropical countries, where even established endemic pathogens are often misdiagnosed. Many of the emerging viruses of the future are already infecting humans but remain to be uncovered by a strategy of disease surveillance in selected populations.
PMID: 25416679 [PubMed - as supplied by publisher]
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