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Monday, 11 August 2014

Bird research this week on PubMed: August 2014 Week 2

PubMed listing for 'bird' OR 'songbird' excluding references to influenza and flu - August 2014 Week 1

1. PLoS One. 2014 Aug 7;9(8):e103236. doi: 10.1371/journal.pone.0103236. eCollection 2014.

The Influence of Vegetation Height Heterogeneity on Forest and Woodland Bird Species Richness across the United States.

Huang Q1, Swatantran A1, Dubayah R1, Goetz SJ2.

Author information:
1Department of Geographical Sciences, University of Maryland, College Park, Maryland, United States of America.
2Woods Hole Research Center, Falmouth, Massachusetts, United States of America.


Avian diversity is under increasing pressures. It is thus critical to understand the ecological variables that contribute to large scale spatial distribution of avian species diversity. Traditionally, studies have relied primarily on two-dimensional habitat structure to model broad scale species richness. Vegetation vertical structure is increasingly used at local scales. However, the spatial arrangement of vegetation height has never been taken into consideration. Our goal was to examine the efficacies of three-dimensional forest structure, particularly the spatial heterogeneity of vegetation height in improving avian richness models across forested ecoregions in the U.S. We developed novel habitat metrics to characterize the spatial arrangement of vegetation height using the National Biomass and Carbon Dataset for the year 2000 (NBCD). The height-structured metrics were compared with other habitat metrics for statistical association with richness of three forest breeding bird guilds across Breeding Bird Survey (BBS) routes: a broadly grouped woodland guild, and two forest breeding guilds with preferences for forest edge and for interior forest. Parametric and non-parametric models were built to examine the improvement of predictability. Height-structured metrics had the strongest associations with species richness, yielding improved predictive ability for the woodland guild richness models (r2 = ∼0.53 for the parametric models, 0.63 the non-parametric models) and the forest edge guild models (r2 = ∼0.34 for the parametric models, 0.47 the non-parametric models). All but one of the linear models incorporating height-structured metrics showed significantly higher adjusted-r2 values than their counterparts without additional metrics. The interior forest guild richness showed a consistent low association with height-structured metrics. Our results suggest that height heterogeneity, beyond canopy height alone, supplements habitat characterization and richness models of forest bird species. The metrics and models derived in this study demonstrate practical examples of utilizing three-dimensional vegetation data for improved characterization of spatial patterns in species richness.
PMID: 25101782 [PubMed - as supplied by publisher]
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2. J Wildl Dis. 2014 Aug 6. [Epub ahead of print]

Fatal Paralytic Shellfish Poisoning in Kittlitz's Murrelet Nestlings, Alaska, USA.

Shearn-Bochsler V1, Lance EW, Corcoran R, Piatt J, Bodenstein B, Frame E, Lawonn J.Author information:
11  US Geological Survey, National Wildlife Health Center, 6006 Schroeder Rd., Madison, Wisconsin 53711, USA.


Abstract Paralytic shellfish poisoning (PSP) is an acute toxic illness in humans resulting from ingestion of shellfish contaminated with a suite of neurotoxins (saxitoxins) produced by marine dinoflagellates, most commonly in the genus Alexandrium. Poisoning also has been sporadically suspected and, less often, documented in marine wildlife, often in association with an outbreak in humans. Kittlitz's Murrelet (Brachyramphus brevirostris) is a small, rare seabird of the Northern Pacific with a declining population. From 2008 to 2012, as part of a breeding ecology study, multiple Kittlitz's Murrelet nests on Kodiak Island, Alaska, were monitored by remote cameras. During the 2011 and 2012 breeding seasons, nestlings from several sites died during mild weather conditions. Remote camera observations revealed that the nestlings died shortly after consuming sand lance (Ammodytes hexapterus), a fish species known to biomagnify saxitoxin. High levels of saxitoxin were subsequently documented in crop content in 87% of nestling carcasses. Marine bird deaths from PSP may be underreported.
PMID: 25098307 [PubMed - as supplied by publisher]
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3. BMC Biol. 2014 Aug 6;12(1):58. [Epub ahead of print]

Assessing vocal performance in complex birdsong: a novel approach.

Geberzahn N, Aubin T.


Background: Vocal performance refers to the ability to produce vocal signals close to physical limits. Such motor skills can be used by conspecifics to assess a signaller's competitive potential. For example it is difficult for birds to produce repeated syllables both rapidly and with a broad frequency bandwidth. Deviation from an upper-bound regression of frequency bandwidth on trill rate has been widely used to assess vocal performance. This approach is, however, only applicable to simple trilled songs, and even then may be affected by differences in syllable complexity.
Results: Using skylarks (Alauda arvensis) as a birdsong model with a very complex song structure, we detected another performance trade-off: minimum gap duration between syllables was longer when the frequency ratio between the end of one syllable and the start of the next syllable (inter-syllable frequency shift) was large. This allowed us to apply a novel measure of vocal performance: vocal gap deviation - the deviation from a lower-bound regression of gap duration on inter-syllable frequency shift. We show that skylarks increase vocal performance in an aggressive context suggesting that this trait might serve as a signal for competitive potential.
Conclusions: We suggest using vocal gap deviation in future studies to assess vocal performance in songbird species with complex structure.
Free Article
PMID: 25096363 [PubMed - as supplied by publisher]
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4. Neurosci Biobehav Rev. 2014 Aug 1. pii: S0149-7634(14)00175-4. doi: 10.1016/j.neubiorev.2014.07.011. [Epub ahead of print]

Behavioral and neural trade-offs between song complexity and stress reaction in a wild and a domesticated finch strain.

Suzuki K1, Ikebuchi M1, Bischof HJ2, Okanoya K 3.

Author information:
1JST, ERATO, Okanoya Emotional Information Project, Wako, Saitama, JAPAN.
2Fakultät Biologie, Universität Bielefeld, Bielefeld, Germany.
3JST, ERATO, Okanoya Emotional Information Project, Wako, Saitama, JAPAN; Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, JAPAN. Electronic address:


The Bengalese finch is the domesticated strain of the wild white-rumped munia. Bengalese finches have been domesticated and reproductively isolated for over 250 years from the wild strain. During this period, the courtship songs of the domesticated birds became phonologically and syntactically complex. In addition, psychological and physiological stress reactions to environmental and social factors diverged between the two strains. Based on our behavioral and histological studies, we consider the balance between the glucocorticoid- and mineralocorticoid receptors in song control nuclei and in the avian amygdala as to determine whether a bird can develop complex songs or rather has to devote the neural resources for the maintenance of stress reactions. We therefore suggest that phonological and syntactical complexity in Bengalese finch songs initially evolved because domestication freed them from species recognition and environmental stress, and then sexual selection increased the complexity. Neural and molecular studies also support the notion that Bengalese finches keep more song plasticity as adults. In conclusion, the present study suggests that domestication changed factors related with psychobiology of stress reactions and learning in finches.
Copyright © 2014 Elsevier Ltd. All rights reserved.
PMID: 25092250 [PubMed - as supplied by publisher]
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5. PLoS One. 2014 Aug 4;9(8):e104031. doi: 10.1371/journal.pone.0104031. eCollection 2014.

Individually specific call feature is not used to neighbour-stranger discrimination: the corncrake case.

Budka M, Osiejuk TS.

Author information:
Department of Behavioural Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.


In various contexts, animals rely on acoustic signals to differentiate between conspecifics. Currently, studies examining vocal signatures use two main approaches. In the first approach, researchers search for acoustic characteristics that have the potential to be individual specific. This approach yields information on variation in signal parameters both within and between individuals and generates practical tools that can be used in population monitoring. In the second approach, playback experiments with natural calls are conducted to discern whether animals are capable of discriminating among the vocal signatures of different individuals. However, both approaches do not reveal the exact signal characteristics that are being used in the discrimination process. In this study, we tested whether an individual-specific call characteristic - namely the length of the intervals between successive maximal amplitude peaks within syllables (PPD) - is crucial in neighbour-stranger discrimination by males of the nocturnal and highly secretive bird species, the corncrake (Crex crex). We conducted paired playback experiments in which corncrakes (n = 47) were exposed to artificial calls with PPD characteristics of neighbour and stranger birds. These artificial calls differed only in PPD structure. The calls were broadcast from a speaker, and we recorded the birds' behavioural responses. Although corncrakes have previously been experimentally shown to discriminate between neighbours and strangers, we found no difference in the responses to the artificial calls representing neighbours versus strangers. This finding demonstrates that even if vocal signatures are individual specific within a species, it does not automatically mean that said signatures are being crucial in discrimination among individuals. At the same time, the birds' aggressive responses to the artificial calls indicated that the information transmitted by PPDs is important in species-specific call recognition and may be used by males and/or females to evaluate sender quality, similarly like sound frequency in some insect species.
PMCID: PMC4121243 Free PMC Article
PMID: 25090457 [PubMed - in process]
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6. Epidemiol Infect. 2014 Aug 4:1-12. [Epub ahead of print]

Empirical analysis suggests continuous and homogeneous circulation of Newcastle disease virus in a wide range of wild bird species in Africa.

Cappelle J1, Caron A1, Servan De Almeida R2, Gil P2, Pedrono M1, Mundava J3, Fofana B4, Balança G1, Dakouo M5, Ould El Mamy AB6, Abolnik C7, Maminiaina OF8, Cumming GS9, De Visscher MN1, Albina E10, Chevalier V1, Gaidet N1.

Author information:
1CIRAD-ES,UR AGIRs, F34398 Montpellier,France.
2CIRAD-BIOS,UMR CMAEE, F34398 Montpellier,France.
3National University of Science and Technology,Bulawayo,Zimbabwe.
4Direction Nationale des Eaux et Forêts,Bamako,Mali.
5Laboratoire Central Vétérinaire,Bamako,Mali.
6Centre National d'Elevage et de Recherche Vétérinaires (CNERV),Nouakchott,Mauritania.
7Poultry Section, Department of Production Animal Studies, Faculty of Veterinary Science,University of Pretoria,Onderstepoort,South Africa.
9Percy FitzPatrick Institute,University of Cape Town,Rondebosch, Cape Town 7701,South Africa.
10INRA,UMR1309 CMAEE, F34398 Montpellier,France.


SUMMARY Newcastle disease (ND) is one of the most important poultry diseases worldwide and can lead to annual losses of up to 80% of backyard chickens in Africa. All bird species are considered susceptible to ND virus (NDV) infection but little is known about the role that wild birds play in the epidemiology of the virus. We present a long-term monitoring of 9000 wild birds in four African countries. Overall, 3·06% of the birds were PCR-positive for NDV infection, with prevalence ranging from 0% to 10% depending on the season, the site and the species considered. Our study shows that ND is circulating continuously and homogeneously in a large range of wild bird species. Several genotypes of NDV circulate concurrently in different species and are phylogenetically closely related to strains circulating in local domestic poultry, suggesting that wild birds may play several roles in the epidemiology of different NDV strains in Africa. We recommend that any strategic plan aiming at controlling ND in Africa should take into account the potential role of the local wild bird community in the transmission of the disease.
PMID: 25090191 [PubMed - as supplied by publisher]
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7. PLoS One. 2014 Aug 4;9(8):e103959. doi: 10.1371/journal.pone.0103959. eCollection 2014.

Effect of Incubation on Bacterial Communities of Eggshells in a Temperate Bird, the Eurasian Magpie (Pica pica).

Lee WY1, Kim M2, Jablonski PG3, Choe JC4, Lee SI5.

Author information:
1Laboratory of Behavioral Ecology and Evolution, Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea.
2Laboratory of Prokaryotic Biology and Bioinformatics, Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea.
3Laboratory of Behavioral Ecology and Evolution, Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea; Museum and Institute of Zoology, Polish Academy of Sciences, Warsaw, Poland.
4Division of EcoScience, Ewha Womans University, Seoul, Republic of Korea.
5 Laboratory of Behavioral Ecology and Evolution, Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea; Institute of Advanced Machinery and Design, Seoul National University, Seoul, Republic of Korea.


Inhibitory effect of incubation on microbial growth has extensively been studied in wild bird populations using culture-based methods and conflicting results exist on whether incubation selectively affects the growth of microbes on the egg surface. In this study, we employed culture-independent methods, quantitative PCR and 16S rRNA gene pyrosequencing, to elucidate the effect of incubation on the bacterial abundance and bacterial community composition on the eggshells of the Eurasian Magpie (Pica pica). We found that total bacterial abundance increased and diversity decreased on incubated eggs while there were no changes on non-incubated eggs. Interestingly, Gram-positive Bacillus, which include mostly harmless species, became dominant and genus Pseudomonas, which include opportunistic avian egg pathogens, were significantly reduced after incubation. These results suggest that avian incubation in temperate regions may promote the growth of harmless (or benevolent) bacteria and suppress the growth of pathogenic bacterial taxa and consequently reduce the diversity of microbes on the egg surface. We hypothesize that this may occur due to difference in sensitivity to dehydration on the egg surface among microbes, combined with the introduction of Bacillus from bird feathers and due to the presence of antibiotics that certain bacteria produce.
PMCID: PMC4121233 Free PMC Article
PMID: 25089821 [PubMed - in process]
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8. Curr Biol. 2014 Jul 30. pii: S0960-9822(14)00782-9. doi: 10.1016/j.cub.2014.06.065. [Epub ahead of print]

Thresholds of Logging Intensity to Maintain Tropical Forest Biodiversity.

Burivalova Z1, Sekercioğlu CH2, Koh LP3.

Author information:
1Department of Environmental Systems Science, ETH Zürich, CHN G 73.1, Universitätstrasse 16, 8092 Zürich, Switzerland. Electronic address:
2Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, 84112 UT, USA; KuzeyDoğa Derneği, Ortakapı Mah., Şehit Yusuf Cad. No. 93 Kat. 1 Merkez, Kars 36100, Turkey.
3Woodrow Wilson School of Public and International Affairs, Princeton University, Robertson Hall, Princeton, NJ 08544-1013, USA; Environment Institute and School of Earth and Environmental Sciences, University of Adelaide, South Australia, 5005 Australia.


Primary tropical forests are lost at an alarming rate, and much of the remaining forest is being degraded by selective logging [1-5]. Yet, the impacts of logging on biodiversity remain poorly understood, in part due to the seemingly conflicting findings of case studies: about as many studies have reported increases in biodiversity after selective logging as have reported decreases [2, 6-11]. Consequently, meta-analytical studies that treat selective logging as a uniform land use tend to conclude that logging has negligible effects on biodiversity [2, 6, 12]. However, selectively logged forests might not all be the same [2, 13-15]. Through a pantropical meta-analysis and using an information-theoretic approach, we compared and tested alternative hypotheses for key predictors of the richness of tropical forest fauna in logged forest. We found that the species richness of invertebrates, amphibians, and mammals decreases as logging intensity increases and that this effect varies with taxonomic group and continental location. In particular, mammals and amphibians would suffer a halving of species richness at logging intensities of 38 m3 ha-1 and 63 m3 ha-1, respectively. Birds exhibit an opposing trend as their total species richness increases with logging intensity. An analysis of forest bird species, however, suggests that this pattern is largely due to an influx of habitat generalists into heavily logged areas while forest specialist species decline. Our study provides a quantitative analysis of the nuanced responses of species along a gradient of logging intensity, which could help inform evidence-based sustainable logging practices from the perspective of biodiversity conservation.
Copyright © 2014 Elsevier Ltd. All rights reserved.
PMID: 25088557 [PubMed - as supplied by publisher]
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9. Vet Surg. 2014 Aug 2. doi: 10.1111/j.1532-950X.2014.12251.x. [Epub ahead of print]

Incisional Colopexy for Treatment of Chronic, Recurrent Colocloacal Prolapse in a Sulphur-Crested Cockatoo (Cacatua galerita).

van Zeeland YR1, Schoemaker NJ, van Sluijs FJ.

Author information:
1Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.



To report a surgical technique for treatment of chronic, recurrent cloacal prolapse in a sulphur-crested cockatoo (Cacatua galerita).


Clinical report ANIMALS: Sulphur-crested cockatoo (n = 1) METHODS: The bird was admitted with a 2-year history of periodic lethargy, decreased appetite, dyschezia, tenesmus, and colocloacal prolapse. An incisional colopexy was performed under general anesthesia to permanently reduce the colocloacal prolapse. To gain access to the coelomic cavity, a ventral U-shaped incision was made, after which the colon and cloaca were restored in their normal anatomic position. Subsequently, the distal colon was sutured to the left abdominal wall.


Colocloacal prolapse was successfully reduced. One month later, cloacoplasty was performed to reduce cloacal width. Long-term follow-up, including a barium contrast study, revealed normal function and an intact colopexy, without recurrence of the prolapse.


Incisional colopexy is feasible despite a bird's relative small body size.
© Copyright 2014 by The American College of Veterinary Surgeons.
PMID: 25088524 [PubMed - as supplied by publisher]
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