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Saturday, 29 November 2014

Within-season increase in parental investment in a long-lived bird species: investment shifts to maximise successful reproduction? J Evol Biol. 2014 Nov 28;

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

J Evol Biol. 2014 Nov 28;

LINK

Authors: Schneider NA, Griesser M

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.


PMID: 25430672 [PubMed - as supplied by publisher]


Behavioural response of a migratory songbird to geographic variation in song and morphology

Behavioural response of a migratory songbird to geographic variation in song and morphology

Authors
Kim G Mortega 1,2,4*, Heiner Flinks 3, and Barbara Helm 2,4

* Corresponding author: Kim G Mortega: kmortega@orn.mpg.de

Author Affiliations
1 Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Radolfzell, 78315, Germany

2 Department of Ornithology, University of Konstanz, Konstanz, 78457, Germany

3 Am Kuhm 19, Borken, 46325, Germany


4 Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK

LINK

Abstract (provisional)
Introduction
Sexually selected traits contribute substantially to evolutionary diversification, for example by promoting assortative mating. The contributing traits and their relevance for reproductive isolation differ between species. In birds, sexually selected acoustic and visual signals often undergo geographic divergence. Clines in these phenotypes may be used by both sexes in the context of sexual selection and territoriality. The ways conspecifics respond to geographic variation in phenotypes can give insights to possible behavioural barriers, but these may depend on migratory behaviour. We studied a migratory songbird, the Stonechat, and tested its responsiveness to geographic variation in male song and morphology. The traits are acquired differently, with possible implications for population divergence. Song can evolve quickly through cultural transmission, and thus may contribute more to the establishment of geographic variation than inherited morphological traits. We first quantified the diversity of song traits from different populations. We then tested the responses of free-living Stonechats of both sexes to male phenotype with playbacks and decoys, representing local and foreign stimuli derived from a range of distances from the local population.
Results
Both sexes discriminated consistently between stimuli from different populations, responding more strongly to acoustic and morphological traits of local than foreign stimuli. Time to approach increased, and time spent close to the stimuli and number of tail flips decreased consistently with geographic distance of the stimulus from the local population. Discriminatory response behaviour was more consistent for acoustic than for morphological traits. Song traits of the local population differed significantly from those of other populations.
Conclusions
Evaluating an individual?s perception of geographic variation in sexually selected traits is a crucial first step for understanding reproductive isolation mechanisms. We have demonstrated that in both sexes of Stonechats the responsiveness to acoustic and visual signals decreased with increasing geographic distance of stimulus origin. These findings confirm consistent, fine discrimination for both learned song and inherited morphological traits in these migratory birds. Maintenance or further divergence in phenotypic traits could lead to assortative mating, reproductive isolation, and potentially speciation.


Thursday, 27 November 2014

Song characteristics track bill morphology along a gradient of urbanization in house finches(Haemorhous mexicanus) Giraudeau et al. Frontiers in Zoology 2014, 11:83

Song characteristics track bill morphology along a gradient of urbanization in house finches(Haemorhous mexicanus)
Frontiers in Zoology 2014, 11:83

pdf: LINK
Web

Mathieu Giraudeau 1,2*, Paul M Nolan 3
Caitlin E Black 4, Stevan R Earl 5
Masaru Hasegawa 6, Kevin J McGraw 1

* Correspondence: giraudeau.mathieu@gmail.com 
1. School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
2. Present address: School of Biological Sciences A08, University of Sydney, Sydney, NSW 2006, Australia
3. Department of Biology, The Citadel, Charleston 29409, SC, USA
4. Department of Biology, The College of Charleston, Charleston 29424, SC, USA
5. Global Institute of Sustainability & School of Sustainability, Arizona State University, Tempe 85287-5402, AZ, USA

6. Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba-shi 305-8572, Ibaraki, Japan


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.

Keywords: Urban impacts, Bill shape, Singing behavior, Noise pollution, Vocal communication


Figure 1. 
Relationship between (A) the average bill width and length at each of our eight study sites for which we gathered data on bill traits (±SE) and (B) the average bill length and the urbanization PC1 scores at each of our eight study sites for which we gathered data on bill traits (±SE).


'Thus, bill length increased and bill width decreased at sites where less land was covered by native undisturbed habitat.'



On the existence and potential functions of low-amplitude vocalizations in North American birds. The Auk, Volume 132, Issue 1, Page 156-166, January 2015.

On the existence and potential functions of low-amplitude vocalizations in North American birds

LINK (not full access)

The Auk, Volume 132, Issue 1, Page 156-166, January 2015. 

Dustin G. Reichard 1,a* and Joseph F. Welklin 1,b

1 Department of Biology, Indiana University, Bloomington, Indiana, USA
a Current address: Department of Evolution and Ecology, University of California, Davis, California, USA
b Current address: Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, USA
* Corresponding author: dgreichard@ucdavis.edu

ABSTRACT

Aggressive encounters between animals often involve significant amounts of signalling before or in lieu of physical fights. When, as is often the case, these apparent threat signals are neither inherently costly nor inherently indicative of fighting ability, we should ask whether they are in fact honest signals, i.e. do they predict that escalation is imminent? While signalling theories have indicated that such ‘conventional’ threat signals can honestly predict escalation, attempts to gather supporting empirical evidence have mostly failed. For example, recent studies in songbirds of song type matching (replying to an opponent's song with the same song type he has just sung) have failed to confirm that it predicts an eventual attack by the signaller. In the present study of song sparrows (Melospiza melodia), we tested the hypothesis that song type matching is an early threat signal in a hierarchical signalling system. We used an improved model-playback design that simulated an escalating intrusion onto the subject's territory: the simulated opponent first sang in hiding from the boundary before moving to the centre of the territory, where he revealed himself and continued to sing. We found that type matching beginning in the boundary phase and continuing into the escalation phase, or beginning immediately after the escalation, reliably predicted both subsequent escalated signalling (soft songs and wing waves) and subsequent attack on the model, supporting the hypothesis that type matching is a reliable early threat signal.

Monday, 24 November 2014

What's new for 'birdRS' in PubMed: November Week 3, 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).

Bird research this week on PubMed

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


PubMed Results
Items 1 - 9 of 9









1. Foodborne Pathog Dis. 2014 Nov 19. [Epub ahead of print]

Potential Use of Caprylic Acid in Broiler Chickens: Effect on Salmonella Enteritidis.

Skřivanová E1, Hovorková P, Cermák L, Marounek M.
Author information:
11 Institute of Animal Science , Department of Physiology of Nutrition and Quality of Animal Products, Prague, Czech Republic .

Abstract

Abstract The effect of dietary caprylic acid (CA) on Salmonella Enteritidis, as well as the surface treatment of chicken skin contaminated with Salmonella Enteritidis was evaluated. To evaluate the dietary effect of CA on Salmonella Enteritidis, the individually housed broiler chickens (n=48) were divided into 4 groups (positive control, negative control, 2.5 g/kg of CA in the feed, and 5 g/kg of CA in the feed). The feed of all groups, except the negative control, was artificially contaminated with Salmonella Enteritidis ATCC 13076 (107 colony-forming units/100 g of feed). Both concentrations of dietary CA significantly decreased counts of Salmonella Enteritidis in the crop and cecum of experimental chickens (p<0.05). The effect of CA in the crop contents was more pronounced than in the cecum. Surface treatment of chilled chicken halves with CA at 1.25 and 2.5 mg/mL significantly decreased Salmonella Enteritidis contamination of chicken skin (p<0.05). The sensory evaluation of the skin and meat showed that treatment of the skin with 1.25 mg/mL of CA worsened odor and appearance of the chicken skin, while sensory traits of chicken meat were not significantly affected. Taste and overall acceptability was not influenced by CA in both meat and skin. Treatment of the skin with 2.5 mg/mL of CA resulted in more pronounced changes of the skin odor and appearance. In conclusion, dietary CA reduced carriage of Salmonella Enteritidis in chickens, whereas surface-treatment reduced or eliminated Salmonella Enteritidis contamination in the processed bird.
PMID: 25407657 [PubMed - as supplied by publisher]
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2. Parasite. 2014;21:62. Epub 2014 Nov 20.

Toxoplasmosis in a bar-shouldered dove (Geopelia humeralis) from the Zoo of Clères, France.

Rigoulet J1, Hennache A1, Lagourette P2, George C2, Longeart L2, Le Net JL2, Dubey JP3.
Author information:
1Muséum National d'Histoire Naturelle, Département des Jardins Botaniques et Zoologiques, 57 rue Cuvier, 75005 Paris, France.
2Laboratoire Anatomo-Pathologique Vétérinaire, BP 303, 37403 Amboise, France.
3United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, Maryland 20705-2350, USA.

Abstract

Toxoplasmosis causes mortality in several avian species, especially passerine birds. Toxoplasmosis was diagnosed in a bar-shouldered dove (Geopelia humeralis) found dead at the zoo of Clères (France). The bird had necrotizing pneumonia and nephritis with intralesional tachyzoites of Toxoplasma gondii. The diagnosis was confirmed by immunostaining with polyclonal rabbit T. gondii antibodies and by transmission electron microscopy. To our knowledge, the bar-shouldered dove is a new host record for T. gondii.
© J. Rigoulet et al., published by EDP Sciences, 2014.
Free Article
PMID: 25407506 [PubMed - as supplied by publisher]
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3. J Evol Biol. 2014 Nov 18. doi: 10.1111/jeb.12527. [Epub ahead of print]

Symbiotic bacteria enable olive flies (Bactrocera oleae) to exploit intractable sources of nitrogen.

Ben-Yosef M1, Pasternak Z, Jurkevitch E, Yuval B.
Author information:
1Department of Entomology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.

Abstract

Insects are often associated with symbiotic micro-organisms, which allow them to utilize nutritionally marginal diets. Adult fruit flies (Diptera: Tephritidae) associate with extracellular bacteria (Enterobacteriaceae) that inhabit their digestive tract. These flies obtain nutrients by foraging for plant exudates, honeydew and bird droppings scattered on leaves and fruit - a nutritional niche which offers ample amounts of carbohydrates, but low quantities of available nitrogen. We identified the bacteria resident in the gut of the olive fly (Bactrocera oleae) - a worldwide pest of olives and examined their contribution to nitrogen metabolism in the adult insect. By suppressing bacteria in the gut and monitoring female fecundity, we demonstrate that bacteria contribute essential amino acids and metabolize urea into an available nitrogen source for the fly, thus significantly elevating egg production. In an ecological context, bacteria were found to be beneficial to females subsisting on bird droppings, but not on honeydew - two natural food sources. We suggest that a main gut bacterium (Candidatus Erwinia dacicola) forms an inseparable, essential part of this fly's nutritional ecology. The evolution of this symbiosis has allowed adult flies to utilize food substrates which are low or imbalanced in assimilable nitrogen and thereby to overcome the nitrogen limitations of their natural diet.
© 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.
PMID: 25403559 [PubMed - as supplied by publisher]
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4. Oecologia. 2014 Sep;176(1):139-47. doi: 10.1007/s00442-014-3013-8. Epub 2014 Jul 9.

Generalist birds govern the seed dispersal of a parasitic plant with strong recruitment constraints.

Mellado A1, Zamora R.
Author information:
1Department of Ecology, Terrestrial Ecology Research Group, University of Granada, Av. Fuentenueva s/n, 18071, Granada, Spain, anamegar@ugr.es.

Abstract

Mistletoes constitute instructive study cases with which to address the role of generalist consumers in the study of plant-animal interactions. Their ranges of safe sites for recruitment are among the most restricted of any plant; therefore, frugivores specializing in mistletoe have been considered almost indispensable for the seed dispersal of these parasitic plants. However, the absence of such specialists in numerous regions inhabited by many mistletoe species raises the question of whether unspecialized vectors may successfully disperse mistletoe seeds to narrowly defined safe sites. Using the European mistletoe Viscum album subsp. austriacum as a study case, we recorded a broad range of 11 bird species that disperse mistletoe seeds. For these species, we studied the mistletoe-visitation rate and feeding behavior to estimate the quantity component of dispersal effectiveness, and the post-foraging microhabitat use, seed handling, and recruitment probabilities of different microhabitats as a measure of the quality component of effectiveness. Both endozoochory and ectozoochory are valid dispersal mechanisms, as the seeds do not need to be ingested to germinate, increasing seed-dispersal versatility. Thrushes were the most effective dispersers, although they were rather inefficient, whereas small birds (both frugivores and non-frugivores) offered low-quantity but high-quality services for depositing seeds directly upon safe sites. As birds behave similarly on parasitized and non-parasitized hosts, and vectors have broad home ranges, reinfection within patches and the colonization of new patches are ensured by an ample assemblage of generalist birds. Thus, a parasitic plant requiring precision in seed dispersal can rely on unspecialized dispersers.
PMID: 25004870 [PubMed - indexed for MEDLINE]
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5. Oecologia. 2014 Sep;176(1):259-71. doi: 10.1007/s00442-014-3001-z. Epub 2014 Jun 29.

Dung beetles in an avian-dominated island ecosystem: feeding and trophic ecology.

Stavert JR1, Gaskett AC, Scott DJ, Beggs JR.
Author information:
1School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand, jamie.stavert@gmail.com.

Abstract

Globally, dung beetles (Scarabaeidae: Scarabaeinae) are linked to many critical ecosystem processes involving the consumption and breakdown of mammal dung. Endemic New Zealand dung beetles (Canthonini) are an anomaly, occurring at high abundance and low diversity on an island archipelago historically lacking terrestrial mammals, except bats, and instead dominated by birds. Have New Zealand's dung beetles evolved to specialise on bird dung or carrion, or have they become broad generalist feeders? We test dietary preferences by analysing nitrogen isotope ratios of wild dung beetles and by performing feeding behaviour observations of captive specimens. We also use nitrogen and carbon stable isotopes to determine if the dung beetle Saphobius edwardsi will consume marine-derived carrion. Nitrogen isotope ratios indicated trophic generalism in Saphobius dung beetles and this was supported by behavioural observations where a broad range of food resources were utilised. Alternative food resource use was further illustrated experimentally by nitrogen and carbon stable isotope signatures of S. edwardsi, where individuals provided with decomposed squid had δ(15)N and δ(13)C values that had shifted toward values associated with marine diet. Our findings suggest that, in the absence of native mammal dung resources, New Zealand dung beetles have evolved a generalist diet of dung and carrion. This may include marine-derived resources, as provided by the seabird colonies present in New Zealand forests before the arrival of humans. This has probably enabled New Zealand dung beetles to persist in indigenous ecosystems despite the decline of native birds and the introduction of many mammal species.
PMID: 24974270 [PubMed - indexed for MEDLINE]
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6. Environ Manage. 2014 May;53(5):999-1004. doi: 10.1007/s00267-014-0256-4. Epub 2014 Mar 6.

Pro-environmental beach driving is uncommon and ineffective in reducing disturbance to beach-dwelling birds.

Weston MA1, Schlacher TA, Lynn D.
Author information:
1Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, 221 Burwood Hwy, Burwood, VIC, 3125, Australia, mweston@deakin.edu.au.

Abstract

Vehicles on beaches cause numerous deleterious effects to coastal wildlife. These impacts may, hypothetically, be lessened if drivers act to reduce disturbance. Since it is unknown to what extent such behavior occurs, and whether it can reduce disturbance, we quantified the behavior of drivers who encountered birds on open-coast, sandy beaches in eastern Australia and the consequent bird responses. Drivers of commercial tourist buses never slowed or altered course ("evaded birds") to avoid disturbing birds; conversely, 34 % of drivers of private cars did evade birds. Drivers of vehicles with fishing rod holders tended (P = 0.09) to evade birds more frequently than non-fishing vehicles. Evasion, when it occurred, was modest, and did not significantly decrease the intensity of bird response or the probability of escapes on the wing. Voluntary behavioral adjustments to alleviate impacts on wildlife may be unworkable, suggesting that other solutions (e.g., beach closures) might be the only effective and feasible way to reduce disturbance to birds on ocean beaches.
PMID: 24599507 [PubMed - indexed for MEDLINE]
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7. Environ Manage. 2014 May;53(5):1005-14. doi: 10.1007/s00267-014-0253-7. Epub 2014 Feb 21.

The impact of nature-based tourism on bird communities: a case study in Pallas-Yllästunturi National Park.

Huhta E1, Sulkava P.
Author information:
1Finnish Forest Research Institute, Rovaniemi Research Unit, P.O. Box 16, 96301, Rovaniemi, Finland, esa.huhta@metla.fi.

Abstract

Nature-based tourism and recreation within and close to protected areas may have negative environmental impacts on biodiversity due to urban development, landscape fragmentation, and increased disturbance. We conducted a 3-year study of disturbances of birds induced by nature-based tourism over a recreational gradient in the Pallas-Yllästunturi National Park and its surroundings in northern Finland. Bird assemblages were studied in highly disturbed areas close to the park (a ski resort, villages, and accommodation areas) and in campfire sites, along hiking routes (recreational areas) and in a forest (control area) within the park. Compared with the forest, the disturbed urbanized areas had higher abundances of human-associated species, corvid species, cavity and building nesters, and edge species. The abundances of managed forest species were higher in campfire sites than in the forest. Hiking trails and campfire sites did not have a negative impact on open-nesting bird species. The most likely reason for this outcome is that most campfire sites were situated at forest edges; this species group prefers managed forests and forest edge as a breeding habitat. The abundances of virgin forest species did not differ among the areas studied. The results of the study suggest that the current recreation pressure has not caused substantial changes in the forest bird communities within the National Park. We suggest that the abundances of urban exploiter species could be used as indicators to monitor the level and changes of urbanization and recreational pressure at tourist destinations.
PMID: 24556796 [PubMed - indexed for MEDLINE]
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Wednesday, 19 November 2014

Generalist birds govern the seed dispersal of a parasitic plant with strong recruitment constraints.

Generalist birds govern the seed dispersal of a parasitic plant with strong recruitment constraints.
Oecologia. 2014 Sep;176(1):139-47





Authors: Mellado A, Zamora R

Abstract

Mistletoes constitute instructive study cases with which to address the role of generalist consumers in the study of plant-animal interactions. Their ranges of safe sites for recruitment are among the most restricted of any plant; therefore, frugivores specializing in mistletoe have been considered almost indispensable for the seed dispersal of these parasitic plants. However, the absence of such specialists in numerous regions inhabited by many mistletoe species raises the question of whether unspecialized vectors may successfully disperse mistletoe seeds to narrowly defined safe sites. Using the European mistletoe Viscum album subsp. austriacum as a study case, we recorded a broad range of 11 bird species that disperse mistletoe seeds. For these species, we studied the mistletoe-visitation rate and feeding behavior to estimate the quantity component of dispersal effectiveness, and the post-foraging microhabitat use, seed handling, and recruitment probabilities of different microhabitats as a measure of the quality component of effectiveness. Both endozoochory and ectozoochory are valid dispersal mechanisms, as the seeds do not need to be ingested to germinate, increasing seed-dispersal versatility. Thrushes were the most effective dispersers, although they were rather inefficient, whereas small birds (both frugivores and non-frugivores) offered low-quantity but high-quality services for depositing seeds directly upon safe sites. As birds behave similarly on parasitized and non-parasitized hosts, and vectors have broad home ranges, reinfection within patches and the colonization of new patches are ensured by an ample assemblage of generalist birds. Thus, a parasitic plant requiring precision in seed dispersal can rely on unspecialized dispersers.


PMID: 25004870 [PubMed - indexed for MEDLINE]

from pubmed: birdRS LINK

Tuesday, 18 November 2014

Age-dependent trait variation: the relative contribution of within-individual change, selective appearance and disappearance in a long-lived seabird.

Age-dependent trait variation: the relative contribution of within-individual change, selective appearance and disappearance in a long-lived seabird.

Journal of Animal Ecology 

LINK


He Zhang*, Oscar Vedder, Peter H. Becker and Sandra Bouwhuis

Institute of Avian Research ‘Vogelwarte Helgoland’, Wilhelmshaven, Germany

*Corresponding author: he.zhang04@googlemail.com

Summary
1. Within populations, the expression of phenotypic traits typically varies with age. Such age-dependent trait variation can be caused by within-individual change (improvement, senescence, terminal effects) and/or selective (dis)appearance of certain phenotypes among older age classes.

2. In this study we applied two methods (decomposition and mixed-modelling) to attribute age-dependent variation in seven phenological and reproductive traits to within-individual change and selective (dis)appearance, in a long-lived seabird, the common tern (Sterna hirundo). 

3.At the population level, all traits, except the probability to breed, improved with age (i.e., phenology advanced and reproductive output increased). Both methods identified within-individual change as the main responsible process, and within individuals, performance improved until age 6-13, before levelling off. In contrast, within individuals, breeding probability decreased to age 10, then levelled off. 

4. Effects of selective appearance and disappearance were small, but showed that longer-lived individuals had a higher breeding probability and bred earlier, and that younger recruits performed better throughout life than older recruits in terms of both phenology and reproductive performance. In the year prior to death, individuals advanced reproduction, suggesting terminal investment. 

5. The decomposition method attributed more age-dependent trait variation to selective disappearance than the mixed-modelling method: 14-36% versus 0-8%, respectively, which we identify to be due to covariance between rates of within-individual change and selective (dis)appearance leading to biased results from the decomposition method. 

6. We conclude that the decomposition method is ideal for visualising processes underlying population change in performance from one age class to the next, but that a mixed-modelling method is required to investigate the significance and relative contribution of age-effects. 

7. Considerable variation in the contribution of the different age-processes between the seven phenotypic traits studied, as well as notable differences between species in patterns of age-dependent trait expression, calls for better predictions regarding optimal allocation strategies with age. 

This article is protected by copyright. All rights reserved.


Monday, 17 November 2014

What's new for 'birdRS' in PubMed: November Week 2, 2014

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

1. Conserv Biol. 2014 Nov 13. doi: 10.1111/cobi.12422. [Epub ahead of print]

Effect of scale on trait predictors of species responses to agriculture.

Gilroy JJ1, Medina Uribe CA, Haugaasen T, Edwards DP.
Author information:
1Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.

Abstract

Species persistence in human-altered landscapes can depend on factors operating at multiple spatial scales. To understand anthropogenic impacts on biodiversity, it is useful to examine relationships between species traits and their responses to land-use change. A key knowledge gap concerns whether these relationships vary depending on the scale of response under consideration. We examined how local- and large-scale habitat variables influence the occupancy dynamics of a bird community in cloud forest zones in the Colombian Chocó-Andes. Using data collected across a continuum of forest and agriculture, we examined which traits best predict species responses to local variation in farmland and which traits best predict species responses to isolation from contiguous forest. Global range size was a strong predictor of species responses to agriculture at both scales; widespread species were less likely to decline as local habitat cover decreased and as distance from forest increased. Habitat specialization was a strong predictor of species responses only at the local scale. Open-habitat species were particularly likely to increase as pasture increased, but they were relatively insensitive to variation in distance to forest. Foraging plasticity and flocking behavior were strong predictors of species responses to distance from forest, but not their responses to local habitat. Species with lower plasticity in foraging behaviors and obligate flock-following species were more likely to decline as distance from contiguous forest increased. For species exhibiting these latter traits, persistence in tropical landscapes may depend on the protection of larger contiguous blocks of forest, rather than the integration of smaller-scale woodland areas within farmland. Species listed as threatened or near threatened on the International Union for Conservation of Nature Red List were also more likely to decline in response to both local habitat quality and isolation from forest relative to least-concern species, underlining the importance of contiguous forests for threatened taxa.
© 2014 Society for Conservation Biology.
PMID: 25395246 [PubMed - as supplied by publisher]
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2.

BMC Evol Biol. 2014 Nov 15;14(1):227. [Epub ahead of print]

Genetic and phenotypic characterization of a hybrid zone between polyandrous Northern and Wattled Jacanas in Western Panama.

Miller MJ, Lipshutz SE, Smith NG, Bermingham E.

Abstract

BackgroundHybridization provides a unique perspective into the ecological, genetic and behavioral context of speciation. Hybridization is common in birds, but has not yet been reported among bird species with a simultaneously polyandrous mating system; a mating system where a single female defends a harem of males who provide nearly all parental care. Unlike simple polyandry, polyandrous mating is extremely rare in birds, with only 1% of bird species employing this mating system. Although it is classically held that females are ¿choosy¿ in avian hybrid systems, nearly-exclusive male parental care raises the possibility that female selection against heterospecific matings might be reduced compared to birds with other mating systems.ResultsWe describe a narrow hybrid zone in southwestern Panama between two polyandrous freshwater waders: Northern Jacana, Jacana spinosa and Wattled Jacana, J. jacana. We document coincident cline centers for three phenotypic traits, mtDNA, and one of two autosomal introns. Cline widths for these six markers varied from seven to 142 km, with mtDNA being the narrowest, and five of the six markers having widths less than 100 km. Cline tails were asymmetrical, with greater introgression of J. jacana traits extending westward into the range of J. spinosa. Likewise, within the hybrid zone, the average hybrid index of phenotypic hybrids was significantly biased towards J. spinosa. Species distribution models indicate that the hybrid zone is located at the edge of a roughly 100 km wide overlap where habitat is predicted to be suitable for both species, with more westerly areas suitable only for spinosa and eastward habitats suitable only for J. jacana.ConclusionThe two species of New World jacanas maintain a narrow, and persistent hybrid zone in western Panama. The hybrid zone may be maintained by the behavioral dominance of J. spinosa counterbalanced by unsuitable habitat for J. spinosa east of the contact zone. Although the two parental species are relatively young, mitochondrial cline width was extremely narrow. This result suggests strong selection against maternally-inherited markers, which may indicate either mitonuclear incompatibilities and/or female choice against heterospecific matings typical of avian hybrid systems, despite jacana sex role reversal.
PMID: 25394718 [PubMed - as supplied by publisher]
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3. Springerplus. 2014 Oct 24;3:630. doi: 10.1186/2193-1801-3-630. eCollection 2014.

Molecular diagnosis of bird-mediated pest consumption in tropical farmland.

Karp DS1, Judson S2, Daily GC3, Hadly EA2.
Author information:
1Department of Biology, Stanford University, Stanford, CA 94305 USA ; Center for Conservation Biology, Stanford University, Stanford, CA 94305 USA ; Now at Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA 94720 USA.
2Department of Biology, Stanford University, Stanford, CA 94305 USA.
3Department of Biology, Stanford University, Stanford, CA 94305 USA ; Center for Conservation Biology, Stanford University, Stanford, CA 94305 USA ; Woods Institute for the Environment, Stanford University, Stanford, CA 94305 USA.

Abstract

Biodiversity loss will likely have surprising and dramatic consequences for human wellbeing. Identifying species that benefit society represents a critical first step towards predicting the consequences of biodiversity loss. Though natural predators prevent billions of dollars in agricultural pest damage annually, characterizing which predators consume pests has proven challenging. Emerging molecular techniques may illuminate these interactions. In the countryside of Costa Rica, we identified avian predators of coffee's most damaging insect pest, the coffee berry borer beetle (Coleoptera:Scolytidae Hypothenemus hampeii), by assaying 1430 fecal samples of 108 bird species for borer DNA. While feeding trials confirmed the efficacy of our approach, detection rates were low. Nevertheless, we identified six species that consume the borer. These species had narrow diet breadths, thin bills, and short wings; traits shared with borer predators in other systems. Borer predators were not threatened; therefore, safeguarding pest control necessitates managing species beyond those at risk of regional extinction by maintaining populations in farmland habitats. Generally, our results demonstrate potential for pairing molecular methods with ecological analyses to yield novel insights into species interactions.
PMID: 25392800 [PubMed]
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4. J Agric Food Chem. 2014 Nov 13. [Epub ahead of print]

Identification of edible bird's nest with amino acid and monosaccharide analysis.

Chua YG, Chan SH, Bloodworth BC, Li SF, Leong LP.

Abstract

This study describes the approach of amino acid and monosaccharide combined with Hotelling T2 range plot to identify edible bird nests (EBN) and non-EBN. Prior to the approach, an analytical method was developed and validated to quantify monosaccharides in EBN. Hotelling T2 range plot of both compounds were successful in predicting the different types of EBN and differentiating EBN and non-EBN. This outcome suggests EBN contains a group of glycoproteins which is not affected by the EBN's coloration, country of origin and/or the processing method of the food item. In addition, the glycoproteins were shown to be unique to EBN. EBN was revealed to be rich in protein and essential amino acids as well as contains a wider variety of monosaccharides than most food items. The overall findings suggest that amino acid and monosaccharide provide information not only on the detected compounds and also insights into the glycoproteins of EBN.
PMID: 25392186 [PubMed - as supplied by publisher]
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5
. J Neurophysiol. 2014 Nov 12:jn.00635.2014. doi: 10.1152/jn.00635.2014. [Epub ahead of print]

Origins of basal ganglia output signals in singing juvenile birds.

Pidoux M1, Bollu T1, Riccelli T1, Goldberg JH2.
Author information:
1Cornell University.
2 Cornell University jessehgoldberg@gmail.com.

Abstract

Across species, complex circuits inside the basal ganglia (BG) converge on pallidal output neurons that exhibit movement-locked firing patterns. Yet the origins of these firing patterns remain poorly understood. In songbirds during vocal babbling, BG output neurons homologous to those found in the primate internal pallidal segment (GPi) are uniformly activated in the tens of milliseconds prior to syllable onsets. To test the origins of this remarkably homogenous BG output signal, we recorded from diverse upstream BG cell types during babbling. Prior to syllable onsets, at the same time that GPi-like neurons were activated, putative medium spiny neurons (MSNs), fast spiking (FS) and tonically active (TAN) interneurons also exhibited transient rate increases. In contrast, pallidal neurons homologous to those found in primate external pallidal segment (GPe) exhibited transient rate decreases. To test origins of these signals, we performed recordings following lesion of corticostriatal inputs from premotor nucleus HVC. HVC lesions largely abolished these syllable-locked signals. Altogether, these findings indicate a striking homogeneity of syllable timing signals in the songbird BG during babbling, and are consistent with a role for the indirect and hyperdirect pathways in transforming cortical inputs into BG outputs during an exploratory behavior.
Copyright © 2009, Journal of Neurophysiology.
PMID: 25392171 [PubMed - as supplied by publisher]
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6. PLoS One. 2014 Nov 12;9(11):e111947. doi: 10.1371/journal.pone.0111947. eCollection 2014.

Spatial distribution of oak mistletoe as it relates to habits of oak woodland frugivores.

Wilson EA1, Sullivan PJ1, Dickinson JL2.
Author information:
1Department of Natural Resources, Cornell University, Ithaca, New York, 14850, United States of America.
2Department of Natural Resources, Cornell University, Ithaca, New York, 14850, United States of America; The Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, New York, 14850, United States of America.

Abstract

This study addresses the underlying spatial distribution of oak mistletoe, Phoradendron villosum, a hemi-parasitic plant that provides a continuous supply of berries for frugivorous birds overwintering the oak savanna habitat of California's outer coast range. As the winter community of birds consuming oak mistletoe varies from group-living territorial species to birds that roam in flocks, we asked if mistletoe volume was spatially autocorrelated at the scale of persistent territories or whether the patterns predicted by long-term territory use by western bluebirds are overcome by seed dispersal by more mobile bird species. The abundance of mistletoe was mapped on trees within a 700 ha study site in Carmel Valley, California. Spatial autocorrelation of mistletoe volume was analyzed using the variogram method and spatial distribution of oak mistletoe trees was analyzed using Ripley's K and O-ring statistics. On a separate set of 45 trees, mistletoe volume was highly correlated with the volume of female, fruit-bearing plants, indicating that overall mistletoe volume is a good predictor of fruit availability. Variogram analysis showed that mistletoe volume was spatially autocorrelated up to approximately 250 m, a distance consistent with persistent territoriality of western bluebirds and philopatry of sons, which often breed next door to their parents and are more likely to remain home when their parents have abundant mistletoe. Using Ripley's K and O-ring analyses, we showed that mistletoe trees were aggregated for distances up to 558 m, but for distances between 558 to 724 m the O-ring analysis deviated from Ripley's K in showing repulsion rather than aggregation. While trees with mistletoe were aggregated at larger distances, mistletoe was spatially correlated at a smaller distance, consistent with what is expected based on persistent group territoriality of western bluebirds in winter and the extreme philopatry of their sons.
Free Article
PMID: 25389971 [PubMed - in process]
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7. Parasit Vectors. 2014 Nov 12;7(1):502. [Epub ahead of print]

Molecular and morphological evidence for three species of Diplostomum (Digenea: Diplostomidae), parasites of fishes and fish-eating birds in Spain.

Pérez-Del-Olmo A, Georgieva S, Pula HJ, Kostadinova A.

Abstract

BackgroundRecent molecular studies have revealed high species diversity of Diplostomum in central and northern Europe. However, our knowledge of the distribution of Diplostomum spp. in the southern distributional range in Europe of the snail intermediate hosts (Lymnaea stagnalis and Radix spp.) is rather limited. This study aims to fill this gap in our knowledge using molecular and morphological evidence.MethodsNineteen fish species and six fish-eating bird species were sampled opportunistically in three regions (Catalonia, Extremadura and Aragon) in Spain. All isolates of Diplostomum spp. were characterised morphologically and molecularly. Partial sequences of the barcode region of the cox1 mitochondrial gene and complete sequences of the ribosomal ITS1-5.8S-ITS2 gene cluster were used for molecular identification of the isolates.ResultsIntegrated morphological and molecular analyses demonstrated the presence of three species among the larval and adult isolates of Diplostomum spp. sampled in Spain: Diplostomum spathaceum (in fish and birds), D. pseudospathaceum (in birds) and Diplostomum sp. referred to as Clade Q sensu Georgieva et al. (Int J Parasitol, 43:57¿72, 2013) (in fish). We detected ten cox1 haplotypes among the isolates of D. spathaceum with only one haplotype shared with adult isolates from central and northern Europe. No specific geographic pattern of the distribution of the novel haplotypes was found.ConclusionThis first molecular exploration of the diversity of Diplostomum spp. in southern Europe indicates much lower species richness compared with the northern regions of Europe.

PMID: 25388753 [PubMed - as supplied by publisher]
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8.

Genet Sel Evol. 2014 Nov 12;46(1):72. doi: 10.1186/s12711-014-0072-6.

Protein evolution of Toll-like receptors 4, 5 and 7 within Galloanserae birds.

Vinkler M1, Bainová H, Bryja J.
Author information:
1Department of Zoology, Faculty of Science, Charles University in Prague, Praha, Czech Republic. michal.vinkler@natur.cuni.cz.

Abstract

BACKGROUND:

Toll-like receptors (TLR) are essential activators of the innate part of the vertebrate immune system. In this study, we analysed the interspecific variability of three TLR (bacterial-sensing TLR4 and TLR5 and viral-sensing TLR7) within the Galloanserae bird clade, investigated their phylogeny, assessed their structural conservation and estimated site-specific selection pressures.

RESULTS:

Physiochemical properties varied according to the TLR analysed, mainly with regards to the surface electrostatic potential distribution. The predicted ligand-binding features (mainly in TLR4 and TLR5) differed between the avian proteins and their fish and mammalian counterparts, but also varied within the Galloanserae birds. We identified 20 positively selected sites in the three TLR, among which several are topologically close to ligand-binding sites reported for mammalian and fish TLR. We described 26, 28 and 25 evolutionarily non-conservative sites in TLR4, TLR5 and TLR7, respectively. Thirteen of these sites in TLR4, and ten in TLR5 were located in functionally relevant regions. The variability appears to be functionally more conserved for viral-sensing TLR7 than for the bacterial-sensing TLR. Amino-acid positions 268, 270, 343, 383, 444 and 471 in TLR4 and 180, 183, 209, 216, 264, 342 and 379 in TLR5 are key candidates for further functional research.

CONCLUSIONS:

Host-pathogen co-evolution has a major effect on the features of host immune receptors. Our results suggest that avian and mammalian TLR may be differentially adapted to pathogen-derived ligand recognition. We have detected signatures of positive selection even within the Galloanserae lineage. To our knowledge, this is the first study to depict evolutionary pressures on Galloanserae TLR and to estimate the validity of current knowledge on TLR function (based on mammalian and chicken models) for non-model species of this clade.
PMCID: PMC4228102 Free PMC Article
PMID: 25387947 [PubMed - in process]
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9
. J Exp Zool A Ecol Genet Physiol. 2014 Nov 11. doi: 10.1002/jez.1894. [Epub ahead of print]

House finch responses to Mycoplasma gallisepticum infection do not vary with experimentally increased aggression.

Adelman JS1, Moore IT, Hawley DM.
Author information:
1Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia.

Abstract

Aggression can alter infectious disease dynamics through two, non-exclusive mechanisms: 1) increasing direct contact among hosts and 2) altering hosts' physiological response to pathogens. Here we examined the latter mechanism in a social songbird by manipulating intraspecific aggression in the absence of direct physical contact. We asked whether the extent of aggression an individual experiences alters glucocorticoid levels, androgen levels, and individual responses to infection in an ecologically relevant disease model: house finches (Haemorhous mexicanus) infected with Mycoplasma gallisepticum (MG). Wild-caught male finches were housed in one of three settings, designed to produce increasing levels of aggression: 1) alone, with no neighbor ("no neighbor"), 2) next to a sham-implanted stimulus male ("sham neighbor"), or 3) next to a testosterone-implanted stimulus male ("testosterone neighbor"). Following one week of social treatment, focal males were experimentally infected with MG, which causes severe conjunctivitis and induces sickness behaviors such as lethargy and anorexia. While social treatment increased aggression as predicted, there were no differences among groups in baseline corticosterone levels, total circulating androgens, or responses to infection. Across all focal individuals regardless of social treatment, pre-infection baseline corticosterone levels were negatively associated with the severity of conjunctivitis and sickness behaviors, suggesting that corticosterone may dampen inflammatory responses in this host-pathogen system. However, because corticosterone levels differed based upon population of origin, caution must be taken in interpreting this result. Taken together, these results suggest that in captivity, although aggression does not alter individual responses to MG, corticosterone may play a role in this disease. J. Exp. Zool. 00A:1-13, 2014. © 2014 Wiley Periodicals, Inc.
© 2014 Wiley Periodicals, Inc.
PMID: 25387693 [PubMed - as supplied by publisher]
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10. An Acad Bras Cienc. 2014 Nov 11;0:0. [Epub ahead of print]

Reproductive phenology and sharing of floral resource among hummingbirds (Trochilidae) in inflorescences of Dahlstedtia pinnata (Benth.) Malme. (Fabaceae) in the Atlantic forest.

Missagia CC1, Verçoza FC2, Alves MA3.
Author information:
1Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
2Programa de Pós-Graduação em Ciências Biológicas (Botânica), Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
3Departamento de Ecologia, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.

Abstract

The purpose of this study was to investigate the reproductive phenology and sharing of floral resource (nectar) of Dahlstedtia pinnata (Benth.) Malme. (Fabaceae), endemic of Atlantic forest, among hummingbirds. For the phenology, we looked at the presence of reproductive structures in the plants, and for floral resource sharing, the frequency of potential pollinators and foraging behaviors were examined. This study was conducted in Pedra Branca State Park, in state of Rio de Janeiro, in a dense ombrophilous forest, between August 2010 and August 2011. Flowering occurred between December 2010 and March 2011, and fruiting between April and June 2011. Hummingbirds' foraging schedules differed significantly, with legitimate visits to the flowers occurring in the morning and illegitimate visits occurring during late morning and the afternoon. Five species visited flowers, three of which were legitimate visitors: Phaethornis ruber, P. pretrei, and Ramphodon naevius. Amazilia fimbriata and Thalurania glaucopis females only visited illegitimately. Phaethornis ruber robbed nectar (78% of illegitimate visits, n=337). Ramphodon naevius, with a territorial foraging behavior and a body size bigger than that of other observed hummingbird species, dominated the floral visits, which suggests that D. pinnata is an important nourishing resource for this endemic bird of the Atlantic forest, currently globally categorized as Near Threatened.

PMID: 25387391 [PubMed - as supplied by publisher]
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11. PLoS One. 2014 Nov 11;9(11):e112347. doi: 10.1371/journal.pone.0112347. eCollection 2014.

Temporal Changes in Randomness of Bird Communities across Central Europe.

Renner SC1, Gossner MM2, Kahl T3, Kalko EK4, Weisser WW2, Fischer M5, Allan E6.
Author information:
1Institute of Experimental Ecology, University of Ulm, Ulm, Germany; Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, Virginia, United States of America.
2Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, Centre for Food and Life Sciences Weihenstephan, Technische Universität München, Freising, Germany.
3Chair of Silviculture, University of Freiburg, Freiburg, Germany.
4Institute of Experimental Ecology, University of Ulm, Ulm, Germany.
5Institute of Plant Sciences and Botanical Garden, University of Bern, Bern, Switzerland.
6Institute of Plant Sciences, University of Bern, Bern, Switzerland.

Abstract

Many studies have examined whether communities are structured by random or deterministic processes, and both are likely to play a role, but relatively few studies have attempted to quantify the degree of randomness in species composition. We quantified, for the first time, the degree of randomness in forest bird communities based on an analysis of spatial autocorrelation in three regions of Germany. The compositional dissimilarity between pairs of forest patches was regressed against the distance between them. We then calculated the y-intercept of the curve, i.e. the 'nugget', which represents the compositional dissimilarity at zero spatial distance. We therefore assume, following similar work on plant communities, that this represents the degree of randomness in species composition. We then analysed how the degree of randomness in community composition varied over time and with forest management intensity, which we expected to reduce the importance of random processes by increasing the strength of environmental drivers. We found that a high portion of the bird community composition could be explained by chance (overall mean of 0.63), implying that most of the variation in local bird community composition is driven by stochastic processes. Forest management intensity did not consistently affect the mean degree of randomness in community composition, perhaps because the bird communities were relatively insensitive to management intensity. We found a high temporal variation in the degree of randomness, which may indicate temporal variation in assembly processes and in the importance of key environmental drivers. We conclude that the degree of randomness in community composition should be considered in bird community studies, and the high values we find may indicate that bird community composition is relatively hard to predict at the regional scale.

PMID: 25386924 [PubMed - in process]
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12. Front Zool. 2014 Oct 31;11(1):80. doi: 10.1186/s12983-014-0080-y. eCollection 2014.

Reproductive responses of birds to experimental food supplementation: a meta-analysis.

Ruffino L1, Salo P1, Koivisto E1, Banks PB2, Korpimäki E1.
Author information:
1Section of Ecology, Department of Biology, University of Turku, FI-20014 Turku, Finland.
2School of Biological Sciences, The University of Sydney, Sydney, Australia.

Abstract

INTRODUCTION:

Food availability is an important environmental cue for animals for deciding how much to invest in reproduction, and it ultimately affects population size. The importance of food limitation has been extensively studied in terrestrial vertebrate populations, especially in birds, by experimentally manipulating food supply. However, the factors explaining variation in reproductive decisions in response to food supplementation remain unclear. By performing meta-analyses, we aim to quantify the extent to which supplementary feeding affects several reproductive parameters in birds, and identify the key factors (life-history traits, behavioural factors, environmental factors, and experimental design) that can induce variation in laying date, clutch size and breeding success (i.e., number of fledglings produced) in response to food supplementation.

RESULTS:

Food supplementation produced variable but mostly positive effects across reproductive parameters in a total of 201 experiments from 82 independent studies. The outcomes of the food effect were modulated by environmental factors, e.g., laying dates advanced more towards low latitudes, and food supplementation appeared not to produce any obvious effect on bird reproduction when the background level of food abundance in the environment was high. Moreover, the increase in clutch size following food addition was more pronounced in birds that cache food, as compared to birds that do not. Supplementation timing was identified as a major cause of variation in breeding success responses. We also document the absence of a detectable food effect on clutch size and breeding success when the target species had poor access to the feed due to competitive interactions with other animals.

CONCLUSIONS:

Our findings indicate that, from the pool of bird species and environments reviewed, extra food is allocated to immediate reproduction in most cases. Our results also support the view that bird species have evolved different life-history strategies to cope with environmental variability in food supply. However, we encourage more research at low latitudes to gain knowledge on how resource allocation in birds changes along a latitudinal gradient. Our results also emphasize the importance of developing experimental designs that minimise competition for the supplemented food and the risk of reproductive bottle-necks due to inappropriate supplementation timings.
PMCID: PMC4222371 Free PMC Article
PMID: 25386221 [PubMed]
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13. PLoS One. 2014 Nov 10;9(11):e112905. doi: 10.1371/journal.pone.0112905. eCollection 2014.

Social information embedded in vocalizations induces neurogenomic and behavioral responses.

Lin LC1, Vanier DR1, London SE2.
Author information:
1Department of Psychology, University of Chicago, Chicago, Illinois, United States of America.
2Department of Psychology, University of Chicago, Chicago, Illinois, United States of America; Institute for Mind and Biology, University of Chicago, Chicago, Illinois, United States of America; Committee on Neurobiology, University of Chicago, Chicago, Illinois, United States of America.

Abstract

Social cues facilitate relationships within communities. Zebra finches form long-term stable mate pairs and produce offspring within a multi-family, multi-generational community that can include hundreds of birds. Males use song to communicate in this complex environment. Males sing as part of their courtship display but also abundantly throughout each day, suggesting a role for their vocal signature outside of a reproductive context. One advantage of a vocal social cue is that it can be exchanged when birds are out of visual contact, as regularly occurs in a zebra finch community. Previous works have demonstrated that females hearing song are affected by their social relationship to the bird singing it, and the immediate social context. Here, we probed the question of whether or not the song itself carried social information, as would be expected from the situations when males sing outside of view of the female. We quantified behavioral and neurogenomic responses to two songs we predicted would have distinct "attractive" qualities in adult females housed in either mixed sex or female-only social communities. Our results show that only mixed sex-housed females show distinctive behavioral and neurogenomic responses to attractive songs. These data are consistent with the idea that the acoustic properties of song carry social information, and that the current social situation modulates the neural and behavioral responses to these signals.
PMCID: PMC4226578 Free PMC Article
PMID: 25384071 [PubMed - in process]
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14. Anat Rec (Hoboken). 2014 Nov 8. doi: 10.1002/ar.23088. [Epub ahead of print]

Morphological features of Herbst corpuscles in the oropharynx of the ostrich (Struthio camelus) and emu (Dromaius novaehollandiae).

Crole MR1, du Plessis L, Soley JT.
Author information:
1Anatomy section, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.

Abstract

The distribution of Herbst corpuscles in the oropharynx of the ostrich and emu has recently been documented. However, although the morphology of these mechanoreceptors is well known in neognathous birds, little structural information is available on the Herbst corpuscles of ratites. Tissue sections from those regions of the oropharynx known to possess a high concentration of Herbst corpuscles were sampled from ostrich and emu heads collected after slaughter and prepared for light and transmission electron microscopy. Intra-oral Herbst corpuscles in the ostrich and emu displayed the same basic components (capsule, outer zone, inner core and axon) described in neognathous birds. However, some important differences were observed, notably, the presence of myofibroblasts in the capsule, sensory cilia in cells of the outer layers, a relatively larger, less organised outer zone and narrower inner core, and variations in the shape of the axon. The previously unreported presence of myofibroblasts in the capsule possibly indicates its ability to contract, thus altering the tension of the capsule, which in turn has implications for the conduction of vibrational stimuli. The sensory cilia in the myofibroblasts of the capsule bordering the outer zone, and in the fibroblasts of the outer zone itself, may play a regulatory role in controlling the contraction of the capsule. Such a function has not previously been reported for Herbst corpuscles in any species of bird. Anat Rec, 2014. © 2014 Wiley Periodicals, Inc.
Copyright © 2014 Wiley Periodicals, Inc.
PMID: 25382625 [PubMed - as supplied by publisher]
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15. Transbound Emerg Dis. 2014 Nov 10. doi: 10.1111/tbed.12290. [Epub ahead of print]

A Transitional Model for the Evaluation of West Nile Virus Transmission in Italy.

Calistri P1, Savini L, Candeloro L, Di Sabatino D, Cito F, Bruno R, Danzetta ML.
Author information:
1Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy.

Abstract

In August 2008, after 10 years of apparent silence, West Nile virus (WNV) infection re-emerged in northern Italy, spreading through the territories of three regions. In the following years, new cases occurred in the same area and additional foci of infection were observed in central and southern Italy, involving also Sicily and Sardinia islands. The Italian Ministry of Health ordered to test by RT-PCR all blood and organ donors from 15th June to 15th November of each year in the infected areas. The period at risk of WNV transmission was defined on the basis of literature data, but a more scientific estimation of the transmission season, under Italian circumstances, needs to be performed. A transitional model previously developed by other Authors was applied and adapted to Italian circumstances, to describe and quantify the WNV transmission cycle between birds and mosquitoes. Culex spp. was considered the main vector, and mosquito parameters were adapted to this genus. Magpies (Pica pica) were considered the main bird host. The model was partially validated through the results of the entomological surveys carried out in central Italy and in Po Valley. The results of the transitional model permitted to calculate the basic reproduction number (R0 ) during 2010 for the whole Italian territory at 1 km of spatial resolution, estimating the risk of WNV transmission during the year and creating detailed risk maps for Italy. The mean values of R0 for the whole Italy varied between 0.4 and 4.8, with values >1 from the end of May to the middle of September. The coastal and flat zones of Italy showed the highest R0 values. Although partially validated, the model showed a substantial acceptable capacity of defining the period at major risk of WNV transmission in Italy, helping Public health authorities in the application of appropriate and timely control and preventive measures.
© 2014 Blackwell Verlag GmbH.
PMID: 25382294 [PubMed - as supplied by publisher]
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16. Anim Cogn. 2014 Nov 9. [Epub ahead of print]

Problem-solving and learning in Carib grackles: individuals show a consistent speed-accuracy trade-off.

Ducatez S1, Audet JN, Lefebvre L.
Author information:
1Department of Biology, McGill University, 1205, Avenue Docteur Penfield, Montreal, QC, H3A 1B1, Canada, simon.ducatez@gmail.com.

Abstract

The generation and maintenance of within-population variation in cognitive abilities remain poorly understood. Recent theories propose that this variation might reflect the existence of consistent cognitive strategies distributed along a slow-fast continuum influenced by shyness. The slow-fast continuum might be reflected in the well-known speed-accuracy trade-off, where animals cannot simultaneously maximise the speed and the accuracy with which they perform a task. We test this idea on 49 wild-caught Carib grackles (Quiscalus lugubris), a tame opportunistic generalist Icterid bird in Barbados. Grackles that are fast at solving novel problems involving obstacle removal to reach visible food perform consistently over two different tasks, spend more time per trial attending to both tasks, and are those that show more shyness in a pretest. However, they are also the individuals that make more errors in a colour discrimination task requiring no new motor act. Our data reconcile some of the mixed positive and negative correlations reported in the comparative literature on cognitive tasks, suggesting that a speed-accuracy trade-off could lead to negative correlations between tasks favouring speed and tasks favouring accuracy, but still reveal consistent strategies based on stable individual differences.
PMID: 25381576 [PubMed - as supplied by publisher]
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17. Int J Biometeorol. 2014 Nov 8. [Epub ahead of print]

Trophic level responses differ as climate warms in Ireland.

Donnelly A1, Yu R, Liu L.
Author information:
1Department of Geography, University of Wisconsin-Milwaukee, Milwaukee, WI, 53201, USA, alison.c.donnelly@gmail.com.

Abstract

Effective ecosystem functioning relies on successful species interaction. However, this delicate balance may be disrupted if species do not respond to environmental change at a similar rate. Here we examine trends in the timing of spring phenophases of groups of species occupying three trophic levels as a potential indicator of ecosystem response to climate warming in Ireland. The data sets were of varying length (1976-2009) and from varying locations: (1) timing of leaf unfolding and May Shoot of a range of broadleaf and conifer tree species, (2) first appearance dates of a range of moth species, and (3) first arrival dates of a range of spring migrant birds. All three groups revealed a statistically significant (P<0.01 and P<0.001) advance in spring phenology that was driven by rising spring temperature (P<0.05; 0.45 °C /decade). However, the rate of advance was greater for moths (1.8 days/year), followed by birds (0.37 days/year) and trees (0.29 days/year). In addition, the length of time between (1) moth emergence and leaf unfolding and (2) moth emergence and bird arrival decreased significantly (P<0.05 and P<0.001, respectively), indicating a decrease in the timing between food supply and demand. These differing trophic level response rates demonstrate the potential for a mismatch in the timing of interdependent phenophases as temperatures rise. Even though these data were not specifically collected to examine climate warming impacts, we conclude that such data may be used as an early warning indicator and as a means to monitor the potential for future ecosystem disruption to occur as climate warms.
PMID: 25380974 [PubMed - as supplied by publisher]
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18. Mol Ecol. 2014 Oct;23(19):4677-8. doi: 10.1111/mec.12905.

Genome scans and elusive candidate genes: detecting the variation that matters for speciation.

Sætre GP.
Author information:
Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P. O. Box 1066 Blindern, N-0316, Oslo, Norway.

Comment on

Abstract

Next-generation sequencing is providing us with vast amounts of genetic data, yet we are currently struggling in our attempts to make sense of them. In particular, it has proven difficult to link phenotypic divergence and speciation to genome level divergence. In the current issue of Molecular Ecology, Ruegg et al. () present new empirical results from two closely related bird taxa. They use a promising approach combining genome scan and candidate gene analysis. Their results suggest that we may have been looking in vain for candidate speciation genes by focusing only on genes found within genomic islands of divergence. This is because genes important in divergence and speciation may not be detected by genome scans and because features of the genomic architecture per se may have a large effect on the pattern of genome divergence.
© 2014 John Wiley & Sons Ltd.
PMID: 25263403 [PubMed - indexed for MEDLINE]
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