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Thursday, 19 November 2015

What's new for 'birdRS' in PubMed: November Week 2, 2015

birdRS - Latest News

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).

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

PubMed Results

1. Benef Microbes. 2015 Nov 13:1-10. [Epub ahead of print] 

Selection, characterisation and evaluation of potential probiotic Lactobacillus spp. isolated from poultry droppings. 
Asghar S(1), Arif M(1), Nawaz M(1), Muhammad K(1), Ali MA(1), Ahmad MD(2), Iqbal S(3), Anjum AA(1), Khan M(1), Nazir J(1). Author information: (1)1 Department of Microbiology, University of Veterinary and Animal Sciences, Out-Fall Road Lahore, 54000 Lahore, Pakistan. (2)2 Department of Epidemiology and Public Health, University of Veterinary and Animal Sciences, Out-Fall Road Lahore, 54000 Lahore, Pakistan. (3)3 Department of Food Science and Human Nutrition, University of Veterinary and Animal Sciences, Out-Fall Road Lahore, 54000 Lahore, Pakistan. 

Aim of the present study was to characterise and evaluate probiotic potential of lactobacilli isolated from indigenous poultry. Lactobacilli were isolated from poultry droppings and identified by genus specific polymerase chain reaction and 16S rRNA gene sequencing. Isolates were characterised in vitro by their ability to tolerate low pH and bile salts, phytase activity, antimicrobial activity, antibiotic susceptibility profile, and autoaggregation and coaggregation with poultry gut pathogens. In vivo evaluation of selected isolates was done by their effect on the body weight gain and immune response of broiler chicks. Total of 90, one-day old chicks, were randomly divided in 9 groups and given selected lactobacilli alone and in combinations (10(8) cfu/bird, daily) from day 7 to day 35. Body weight gain and humoral immune response to New Castle Disease Virus (NDV) vaccine were determined weekly. Three lactobacilli isolates (SMP52, SMP64 and SMP70) were selected as potentially probiotic bacteria on the basis of in vitro characterisation and identified as Lactobacillus crispatus, Lactobacillus casei and L. crispatus, respectively. Chicks supplemented with 'SMP52', 'SMP64', 'SMP70' and 'SMP64+SMP70' and a commercial probiotic product (Protexin) showed significantly higher mean weight gain per bird (1,584±35.2, 1,629±30.6, 1,668±34.7, 1,619±29.5 and 1,576±31.7 g/bird, respectively) as compared to negative control group (1,394±26.7 g/bird), on day 35. SMP 70 also showed significantly higher geometric mean titre against NDV vaccine at day 21 as compared to negative control. It is concluded that L. crispatus SMP52, L. casei SMP64 and L. crispatus SMP70 are potential probiotic candidates which alone or in different combinations may increase body weight of broilers. PMID: 26565086 [PubMed - as supplied by publisher] 

2. Environ Sci Pollut Res Int. 2015 Nov 13. [Epub ahead of print] 

Brain cholinesterase reactivation as a marker of exposure to anticholinesterase pesticides: a case study in a population of yellow-legged gull Larus michahellis (Naumann, 1840) along the northern coast of Portugal. 
Santos CS(1,)(2), Monteiro MS(3), Soares AM(3,)(4), Loureiro S(3). Author information: (1)Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal. (2)Department of Biology, Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium. (3)Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal. (4)Programa de Pós-Graduação em Produção Vegetal, Universidade Federal do Tocantins, Campus de Gurupi. Rua Badejós, Zona Rural, Cx. Postal 66-CEP: 77402-970, Gurupi-TO, Brasil. 

Between late 2010 to early 2011, an increased mortality in gulls was observed along the northern coast of Portugal, with individuals exhibiting neurologic disorders consistent with an eventual anticholinesterase pesticide poisoning event. To clarify if this mortality was related to organophosphate (OP) and/or carbamate (CB) poisoning, chemical and spontaneous cholinesterase (ChE) reactivation was tested in the brain of the yellow-legged gull (Larus michahellis). Initial brain ChE activity in L. michahellis was 40.92 ± 5.23 U/mg of protein (average ± SE). Following chemical and spontaneous reactivation, ChE activity increased in average 70.38 ± 48.59 % and 131.95 ± 92.64 %, respectively. ChE reactivation was found to decrease at increasing concentrations of the oxime pyridine-2-aldoxime methochloride and dilution factor, underscoring the importance of first optimizing the assay conditions prior to its use on bird species. These results suggest that birds analysed could have been exposed to OP and CB pesticide compounds and that in most cases CB exposure appeared to be the main cause of birds poisoning. These results are an important contribution to environmental monitoring as it demonstrates the suitability of L. michaellis as sentinel species of OP and CB pesticides within an urban environment. PMID: 26564198 [PubMed - as supplied by publisher] 

3. Physiol Rep. 2015 Nov;3(11). pii: e12599. doi: 10.14814/phy2.12599. 

Reduced vocal variability in a zebra finch model of dopamine depletion: implications for Parkinson disease. 
Miller JE(1), Hafzalla GW(2), Burkett ZD(2), Fox CM(3), White SA(2). Author information: (1)Departments of Neuroscience and Speech, Language and Hearing Sciences of the University of Arizona, Tucson, Arizona (2)Integrative Biology & Physiology, University of California, Los Angeles, California. (3)National Center for Voice and Speech, Denver, Colorado. 

Midbrain dopamine (DA) modulates the activity of basal ganglia circuitry important for motor control in a variety of species. In songbirds, DA underlies motivational behavior including reproductive drive and is implicated as a gatekeeper for neural activity governing vocal variability. In the zebra finch, Taeniopygia guttata, DA levels increase in Area X, a song-dedicated subregion of the basal ganglia, when a male bird sings his courtship song to a female (female-directed; FD). Levels remain stable when he sings a less stereotyped version that is not directed toward a conspecific (undirected; UD). Here, we used a mild dose of the neurotoxin 6-hydroxydopamine (6-OHDA) to reduce presynaptic DA input to Area X and characterized the effects on FD and UD behaviors. Immunoblots were used to quantify levels of tyrosine hydroxylase (TH) as a biomarker for DA afferent loss in vehicle- and 6-OHDA-injected birds. Following 6-OHDA administration, TH signals were lower in Area X but not in an adjacent subregion, ventral striatal-pallidum (VSP). A postsynaptic marker of DA signaling was unchanged in both regions. These observations suggest that effects were specific to presynaptic afferents of vocal basal ganglia. Concurrently, vocal variability was reduced during UD but not FD song. Similar decreases in vocal variability are observed in patients with Parkinson disease (PD), but the link to DA loss is not well-understood. The 6-OHDA songbird model offers a unique opportunity to further examine how DA loss in cortico-basal ganglia pathways affects vocal control. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. PMID: 26564062 [PubMed] 

4. Sci Rep. 2015 Nov 13;5:16600. doi: 10.1038/srep16600. 

Large diurnal temperature range increases bird sensitivity to climate change. 
Briga M(1), Verhulst S(1). Author information: (1)Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands. 

Climate variability is changing on multiple temporal scales, and little is known of the consequences of increases in short-term variability, particularly in endotherms. Using mortality data with high temporal resolution of zebra finches living in large outdoor aviaries (5 years, 359.220 bird-days), we show that mortality rate increases almost two-fold per 1°C increase in diurnal temperature range (DTR). Interestingly, the DTR effect differed between two groups with low versus high experimentally manipulated foraging costs, reflecting a typical laboratory 'easy' foraging environment and a 'hard' semi-natural environment respectively. DTR increased mortality on days with low minimum temperature in the easy foraging environment, but on days with high minimum temperature in the semi-natural environment. Thus, in a natural environment DTR effects will become increasingly important in a warming world, something not detectable in an 'easy' laboratory environment. These effects were particularly apparent at young ages. Critical time window analyses showed that the effect of DTR on mortality is delayed up to three months, while effects of minimum temperature occurred within a week. These results show that daily temperature variability can substantially impact the population viability of endothermic species. PMID: 26563993 [PubMed - as supplied by publisher] 

5. Rapid Commun Mass Spectrom. 2015 Dec 30;29(24):2328-36. doi: 10.1002/rcm.7401. 

Analysis of stable isotope ratios in blood of tracked wandering albatrosses fails to distinguish a δ(13) C gradient within their winter foraging areas in the southwest Atlantic Ocean. 
Ceia FR(1), Ramos JA(1), Phillips RA(2), Cherel Y(3), Jones DC(2), Vieira RP(1,)(4,)(5), Xavier JC(1,)(2). Author information: (1)MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, Universidade de Coimbra, 3004-517, Coimbra, Portugal. (2)British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK. (3)Centre d'Etudes Biologiques de Chizé, UPR 7372 du CNRS-Université de La Rochelle, 79360, Villiers-en-Bois, France. (4)Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal. (5)Ocean and Earth Science, National Oceanography Centre, Southampton, European Way, Southampton, SO14 3ZH, UK. 

RATIONALE: The main limitation of isotopic tracking for inferring distribution is the lack of detailed reference maps of the isotopic landscape (i.e. isoscapes) in the marine environment. Here, we attempt to map the marine δ(13) C isoscape for the southwestern sector of the Atlantic Ocean, and assess any temporal variation using the wandering albatross as a model species. METHODS: Tracking data and blood and diet samples were collected monthly from wandering albatrosses rearing chicks at Bird Island, South Georgia, during the austral winter between May and October 2009. The δ(13) C and δ(15) N values were measured by mass spectrometry in plasma and blood cells, and related to highly accurate data on individual movements and feeding activity obtained using three types of device: GPS, activity (immersion) loggers and stomach temperature probes. RESULTS: The tracked birds foraged in waters to the north or northwest of South Georgia, including the Patagonian shelf-break, as far as 2000 km from the colony. The foraging region encompassed the two main fronts in the Southern Ocean (Polar and Subantarctic fronts). The δ(13) C values varied by only 2.1 ‰ in plasma and 2.5 ‰ in blood cells, and no relationships were found between the δ(13) C values in plasma and the mean latitude or longitude of landings or feeding events of each individual. CONCLUSIONS: The failure to distinguish a major biogeographic gradient in δ(13) C values suggest that these values in the south Atlantic Ocean are fairly homogeneous. There was no substantial variation among months in either the δ(13) C or the δ(15) N values of plasma or blood cells of tracked birds. As birds did not show a significant change in diet composition or foraging areas during the study period, these results provide no evidence for major temporal variation in stable isotope ratios in consumer tissues, or in the regional marine isoscape in the austral winter of 2009. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd. PMID: 26563703 [PubMed - in process] 

6. Nat Commun. 2015 Nov 13;6:8902. doi: 10.1038/ncomms9902. 

Bird embryos uncover homology and evolution of the dinosaur ankle. 
Ossa-Fuentes L(1), Mpodozis J(2), Vargas AO(1). Author information: (1)Departamento de Biología, Laboratorio de Ontogenia y Filogenia, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile. (2)Departamento de Biología, Laboratorio de Neurobiología y Biología del Conocer, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile. 

The anklebone (astragalus) of dinosaurs presents a characteristic upward projection, the 'ascending process' (ASC). The ASC is present in modern birds, but develops a separate ossification centre, and projects from the calcaneum in most species. These differences have been argued to make it non-comparable to dinosaurs. We studied ASC development in six different orders of birds using traditional techniques and spin-disc microscopy for whole-mount immunofluorescence. Unexpectedly, we found the ASC derives from the embryonic intermedium, an ancient element of the tetrapod ankle. In some birds it comes in contact with the astragalus, and, in others, with the calcaneum. The fact that the intermedium fails to fuse early with the tibiale and develops an ossification centre is unlike any other amniotes, yet resembles basal, amphibian-grade tetrapods. The ASC originated in early dinosaurs along changes to upright posture and locomotion, revealing an intriguing combination of functional innovation and reversion in its evolution. PMID: 26563435 [PubMed - as supplied by publisher] 

7. Jpn J Vet Res. 2015 Aug;63(3):95-105. 

Quantitative and qualitative morphologic, cytochemical and ultrastructural characteristics of blood cells in the Crested Serpent eagle and Shikra. 
Salakij C, Kasorndorkbua C, Salakij J, Suwannasaeng P, Jakthong P. 

The Crested Serpent eagle (Spilornis cheela) is a bird of prey found in the tropical rain forest in Thailand. The Shikra (Accipiter badius) is a sparrow hawk and common resident in Thailand. Blood samples from 9 Crested Serpent eagles and 12 Shikras were obtained from September 2010 to November 2014. They were clinically healthy and negative for blood parasites detectable by light microscopy and molecular techniques (partial cytochrome b gene for avian malaria and partial 18S rRNA gene for trypanosome). Cytochemical staining (Sudan black B, peroxidase, α-naphthyl acetate esterase, and β-glucuronidase) and transmission electron microscopy were performed. Hematological results were reported as the mean ± standard deviation and median. Heterophils were the most prevalent leukocytes in the Crested Serpent eagle, but in the Shikra, lymphocytes were the most prevalent leukocytes. In the Shikra, some vacuoles were observed in the cytoplasm of the eosinophils. All blood cells in both types of raptors stained positively for β-glucuronidase but negatively for peroxidase. The ultrastructure of heterophils showed more clearly differentiate long rod granules in Crested Serpent eagle and spindle-shaped granules in Shikra. The ultrastructure of the eosinophils in the Crested Serpent eagle revealed varied electron-dense, round-shaped granules with round, different electron-dense areas in the centers of some granules, which differed from the structure reported for other raptors. These quantitative results may be useful for clinical evaluations of Crested Serpent eagles and Shikras that are undergoing rehabilitation for release. PMID: 26563029 [PubMed - in process] 

8. Toxicol Lett. 2015 Nov 9. pii: S0378-4274(15)30098-9. doi: 10.1016/j.toxlet.2015.11.002. [Epub ahead of print] 

Toxicokinetics of perfluorooctane sulfonate in rabbits under environmentally realistic exposure conditions and comparative assessment between mammals and birds. 
Tarazona JV(1), Rodríguez C(2), Alonso E(1), Sáez M(3), González F(4), San Andrés MD(4), Jiménez B(3), San Andrés MI(4). Author information: (1)Laboratory for Ecotoxicology, INIA, Madrid, Spain. (2)Toxicology and Pharmacology Department. Veterinary Faculty, UCM, Madrid, Spain. Electronic address: (3)Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, Spanish National Research Council (IQOG-CSIC), Madrid, Spain. (4)Toxicology and Pharmacology Department. Veterinary Faculty, UCM, Madrid, Spain. 

This article describes the toxicokinetics of perfluorooctane sulfonate (PFOS) in rabbits under low repeated dosing, equivalent to 0.085μg/kg per day, and the observed differences between rabbits and chickens. The best fitting for both species was provided by a simple pseudo monocompartmental first-order kinetics model, regulated by two rates, and accounting for real elimination as well as binding of PFOS to non-exchangeable structures. Elimination was more rapid in rabbits, with a pseudo first-order dissipation half-life of 88 days compared to the 230 days observed for chickens. By contrast, the calculated assimilation efficiency for rabbits was almost 1, very close to full absorption, significantly higher than the 0.66 with confidence intervals of 0.64 and 0.68 observed for chickens. The results confirm a very different kinetics than that observed in single-dose experiments confirming clear dose-related differences in apparent elimination rates in rabbits, as previously described for humans and other mammals; suggesting the role of a capacity-limited saturable process resulting in different kinetic behaviours for PFOS in high dose versus environmentally relevant low dose exposure conditions. The model calculations confirmed that the measured maximum concentrations were still far from the steady state situation, and that the different kinetics between birds and mammals should may play a significant role in the biomagnifications assessment and potential exposure for humans and predators. For the same dose regime, the steady state concentration was estimated at about 36μg PFOS/L serum for rabbits, slightly above one-half of the 65μg PFOS/L serum estimated for chickens. The toxicokinetic parameters presented here can be used for higher-tier bioaccumulation estimations of PFOS in rabbits and chickens as starting point for human health exposure assessments and as surrogate values for modeling PFOS kinetics in wild mammals and bird in exposure assessment of predatory species. Copyright © 2015. Published by Elsevier Ireland Ltd. PMID: 26562771 [PubMed - as supplied by publisher] 

9. PLoS One. 2015 Nov 11;10(11):e0141505. doi: 10.1371/journal.pone.0141505. eCollection 2015. 

Likeability of Garden Birds: Importance of Species Knowledge & Richness in Connecting People to Nature. 
Cox DT(1), Gaston KJ(1). Author information: (1)Environment & Sustainability Institute, University of Exeter, Penryn, Cornwall, United Kingdom. 

Interacting with nature is widely recognised as providing many health and well-being benefits. As people live increasingly urbanised lifestyles, the provision of food for garden birds may create a vital link for connecting people to nature and enabling them to access these benefits. However, it is not clear which factors determine the pleasure that people receive from watching birds at their feeders. These may be dependent on the species that are present, the abundance of individuals and the species richness of birds around the feeders. We quantitatively surveyed urban households from towns in southern England to determine the factors that influence the likeability of 14 common garden bird species, and to assess whether people prefer to see a greater abundance of individuals or increased species richness at their feeders. There was substantial variation in likeability across species, with songbirds being preferred over non-songbirds. Species likeability increased for people who fed birds regularly and who could name the species. We found a strong correlation between the number of species that a person could correctly identify and how connected to nature they felt when they watched garden birds. Species richness was preferred over a greater number of individuals of the same species. Although we do not show causation this study suggests that it is possible to increase the well-being benefits that people gain from watching birds at their feeders. This could be done first through a human to bird approach by encouraging regular interactions between people and their garden birds, such as through learning the species names and providing food. Second, it could be achieved through a bird to human approach by increasing garden songbird diversity because the pleasure that a person receives from watching an individual bird at a feeder is dependent not only on its species but also on the diversity of birds at the feeder. PMID: 26560968 [PubMed - in process] 

10. Braz J Biol. 2015 Nov 10. pii: S1519-69842015005003414. [Epub ahead of print] 

Hematological, morphological and morphometric characteristics of blood cells from rhea, Rhea Americana (Struthioniformes: Rheidae): a standard for Brazilian birds. 
Gallo SS(1), Ederli NB(2), Bôa-Morte MO(1), Oliveira FC(1). Author information: (1)Laboratório de Sanidade Animal, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, Brazil. (2)Universidade Federal do Pará, Marajó-Breves, PA, Brazil. 

Blood exams are an indispensable tool in bird medicine. This study aimed at describing values and aspects of rheas' hematology, Rhea americana, as well as analyzing the morphology and morphometry of all blood cells. Fifty eight adult rheas of both sexes from two farms, one in Cachoeiro de Itapemirim, Espírito Santo State and the other in São Carlos, São Paulo State, were selected. Blood samples were taken and RBC count, PCV and Hb levels measured and used in hematimetric indexes calculations. The total and differentiated leukocyte counts, as well as the TPP and fibrinogen were determined. Erythrocytes, leukocytes and thrombocytes were identified and characterized morphologically. The values for the red series and hematimetric indexes were: RBC (2.81±0.15×106/μL), PCV (44.20±2.86%), Hb (12.12±0.74 g/dL), MCV (15.75±0.89 fL), MCH (43.18±1.82 pg), MCHC (27.44±0.80 g/dL); the values of white series were: WBC (12.072±4116/μL), heterophils (64.10±9.90%), eosinophils (2.05±2.06%), monocytes (6.40±2.99%), lymphocytes (26.93±9.62%), basophils (0.52±1.27%). One may conclude that on average, rheas' blood cells are larger than those of other birds, but these cells in smears cannot be differentiated only by their size. Besides rheas' leukocytes have different components and coloring as in other bird species, however, there are no components or staining aspects unique to the species. PMID: 26560670 [PubMed - as supplied by publisher] 

11. Braz J Biol. 2015 Nov 10. pii: S1519-69842015005005714. [Epub ahead of print] 

The impact of anthropogenic food supply on fruit consumption by dusky-legged guan (Penelope obscura Temminck, 1815): potential effects on seed dispersal in an Atlantic forest area. 
Vasconcellos-Neto J(1), Ramos RR(1), Pinto LP(1). Author information: (1)Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brazil. 

Frugivorous birds are important seed dispersers and influence the recruitment of many plant species in the rainforest. The efficiency of this dispersal generally depends on environment quality, bird species, richness and diversity of resources, and low levels of anthropogenic disturbance. In this study, we compared the sighting number of dusky-legged guans (Penelope obscura) by km and their movement in two areas of Serra do Japi, one around the administrative base (Base) where birds received anthropogenic food and a pristine area (DAE) with no anthropogenic resource. We also compared the richness of native seeds in feces of birds living in these two areas. Although the abundance of P. obscura was higher in the Base, these individuals moved less, dispersed 80% fewer species of plants and consumed 30% fewer seeds than individuals from DAE. The rarefaction indicated a low richness in the frugivorous diet of birds from the Base when compared to the populations from DAE. We conclude that human food supply can interfere in the behavior of these birds and in the richness of native seeds dispersed. PMID: 26560665 [PubMed - as supplied by publisher] 

12. Braz J Biol. 2015 Nov 10. pii: S1519-69842015005002914. [Epub ahead of print] 

Trace elements concentrations in Buff-breasted Sandpiper sampled in Lagoa do Peixe National Park, Southern Brazil. 
Scherer JF(1), Scherer AL(1), Barbieri E(2), Petry MV(1), Valiati VH(1). Author information: (1)Centro de Ciências da Saúde, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil. (2)Instituto de Pesca, Cananéia, SP, Brazil. 

Cadmium, cobalt, chromium, copper, manganese, nickel, zinc and lead concentrations were detected in feathers of Buff-breasted Sandpipers (Calidris subruficollis) captured during the non-breeding season and analyzed with relationship to body mass. Of these metals tested for, only copper levels (2.28 µg/g) were positively correlated with bird body mass. Zinc levels showed higher concentration (67.97 µg/g) than the other metals, and cadmium levels showed the lowest concentration (0.14 µg/g). Trace element concentrations were below toxicity levels for all tested chemicals and we suggest that this probably reflects that essential elements are maintained there by normal homeostatic mechanism and that no excessive environmental exposure to these elements during migration or on the wintering area is suggested by these results. PMID: 26560652 [PubMed - as supplied by publisher] 

13. PLoS One. 2015 Nov 11;10(11):e0141194. doi: 10.1371/journal.pone.0141194. eCollection 2015. 

Analysis of the Optimal Duration of Behavioral Observations Based on an Automated Continuous Monitoring System in Tree Swallows (Tachycineta bicolor): Is One Hour Good Enough? 
Lendvai ÁZ(1,)(2), Akçay Ç(1), Ouyang JQ(1,)(3), Dakin R(4,)(5), Domalik AD(5), St John PS(5), Stanback M(6), Moore IT(1), Bonier F(1,)(5). Author information: (1)Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America. (2)Department of Evolutionary Zoology and Human Biology, University of Debrecen, Debrecen, Hungary. (3)The Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands. (4)Department of Zoology, University of British Columbia, Vancouver, BC, Canada. (5)Department of Biology, Queen's University, Kingston, ON, Canada. (6)Department of Biology, Davidson College, North Carolina, United States of America. 

Studies of animal behavior often rely on human observation, which introduces a number of limitations on sampling. Recent developments in automated logging of behaviors make it possible to circumvent some of these problems. Once verified for efficacy and accuracy, these automated systems can be used to determine optimal sampling regimes for behavioral studies. Here, we used a radio-frequency identification (RFID) system to quantify parental effort in a bi-parental songbird species: the tree swallow (Tachycineta bicolor). We found that the accuracy of the RFID monitoring system was similar to that of video-recorded behavioral observations for quantifying parental visits. Using RFID monitoring, we also quantified the optimum duration of sampling periods for male and female parental effort by looking at the relationship between nest visit rates estimated from sampling periods with different durations and the total visit numbers for the day. The optimum sampling duration (the shortest observation time that explained the most variation in total daily visits per unit time) was 1h for both sexes. These results show that RFID and other automated technologies can be used to quantify behavior when human observation is constrained, and the information from these monitoring technologies can be useful for evaluating the efficacy of human observation methods. PMID: 26559407 [PubMed - in process] 

14. Sci Rep. 2015 Nov 10;5:16150. doi: 10.1038/srep16150. 

Virulence of recurrent infestations with Borrelia-infected ticks in a Borrelia-amplifying bird. 
Heylen DJ(1), Müller W(2), Vermeulen A(2), Sprong H(3), Matthysen E(1). Author information: (1)Evolutionary Ecology Group, Department of Biology, University of Antwerp, Belgium. (2)Ethology Group, Department of Biology, University of Antwerp, Belgium. (3)Laboratory for Zoonoses and Environmental Microbiology, National Institute for Public Health and Environment (RIVM), Bilthoven, the Netherlands. 

Lyme disease cases caused by Borrelia burgdorferi s.l. bacteria is increasing steadily in Europe, in part due to the expansion of the vector, Ixodes ricinus. Wild reservoir hosts are typically recurrently infested. Understanding the impact of these cumulative parasite exposures on the host's health is, therefore, central to predict the distribution of tick populations and their pathogens. Here, we have experimentally investigated the symptoms of disease caused by recurrent infestations in a common songbird (Parus major). Birds were exposed three times in succession to ticks collected in a Borrelia endemic area. Health and immune measures were analyzed in order to investigate changes in response to tick infestation and Borrelia infection rate. Nitric oxide levels increased with the Borrelia infection rate, but this effect was increasingly counteracted by mounting tick infestation rates. Tick infestations equally reduced haematocrit during each cycle. But birds overcompensated in their response to tick feeding, having higher haematocrit values during tick-free periods depending on the number of ticks they had been previously exposed to. Body condition showed a similar overshooting response in function of the severity of the Borrelia infection. The observed overcompensation increases the bird's energetic needs, which may result in an increase in transmission events. PMID: 26553505 [PubMed - in process] 

15. J Anat. 2015 Nov 10. doi: 10.1111/joa.12406. [Epub ahead of print] 

A reappraisal of Cerebavis cenomanica (Aves, Ornithurae), from Melovatka, Russia. 
Walsh SA(1,)(2), Milner AC(3), Bourdon E(4). Author information: (1)Department of Natural Sciences, National Museums Scotland, Edinburgh, UK. (2)School of Geosciences, University of Edinburgh, Edinburgh, UK. (3)Department of Earth Sciences, The Natural History Museum, London, UK. (4)Natural History Museum of Denmark, Section of Biosystematics, Copenhagen, Denmark. 

The evolution of the avian brain is of crucial importance to studies of the transition from non-avian dinosaurs to modern birds, but very few avian fossils provide information on brain morphological development during the Mesozoic. An isolated specimen from the Cenomanian of Melovatka in Russia was described by Kurochkin and others as a fossilized brain, designated the holotype of Cerebavis cenomanica Kurochkin and Saveliev and tentatively referred to Enantiornithes. We have previously highlighted that this specimen is an incomplete skull, rendering the diagnostic characters invalid and Cerebavis cenomanica a nomen dubium. We provide here a revised diagnosis of Cerebavis cenomanica based on osteological characters, and a reconstruction of the endocranial morphology (= brain shape) based on μCT investigation of the braincase. Absence of temporal fenestrae indicates an ornithurine affinity for Cerebavis. The brain of this taxon was clearly closer to that of modern birds than to Archaeopteryx and does not represent a divergent evolutionary pathway as originally concluded by Kurochkin and others. No telencephalic wulst is present, suggesting that this advanced avian neurological feature was not recognizably developed 93 million years ago. © 2015 Anatomical Society. PMID: 26553244 [PubMed - as supplied by publisher] 

16. Evolution. 2015 Nov 10. doi: 10.1111/evo.12817. [Epub ahead of print] 

No substitute for real data: a cautionary note on the use of phylogenies from birth-death polytomy resolvers for downstream comparative analyses. 
Rabosky DL(1). Author information: (1)Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, MI, 48103. 

The statistical estimation of phylogenies is always associated with uncertainty, and accommodating this uncertainty is an important component of modern phylogenetic comparative analysis. The birth-death polytomy resolver is a method of accounting for phylogenetic uncertainty that places missing (unsampled) taxa onto phylogenetic trees, using taxonomic information alone. Recent studies of birds and mammals have used this approach to generate pseudo-posterior distributions of phylogenetic trees that are complete at the species level, even in the absence of genetic data for many species. Many researchers have used these distributions of phylogenies for downstream evolutionary analyses that involve inferences on phenotypic evolution, geography, and community assembly. I demonstrate that the use of phylogenies constructed in this fashion is inappropriate for many questions involving traits. Because species are placed on trees at random with respect to trait values, the birth-death polytomy resolver breaks down natural patterns of trait phylogenetic structure. Inferences based on these trees are predictably and often drastically biased in a direction that depends on the underlying (true) pattern of phylogenetic structure in traits. I illustrate the severity of the phenomenon for both continuous and discrete traits using examples from a global bird phylogeny. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved. PMID: 26552857 [PubMed - as supplied by publisher] 

17. Ecol Appl. 2015 Sep;25(6):1669-80. 

Evaluating species richness: Biased ecological inference results from spatial heterogeneity in detection probabilities. 
McNew LB, Handel CM. 

Accurate estimates of species richness are necessary to test predictions of ecological theory and evaluate biodiversity for conservation purposes. However, species richness is difficult to measure in the field because some species will almost always be overlooked due to their cryptic nature or the observer's failure to perceive their cues. Common measures of species richness that assume consistent observability across species are inviting because they may require only single counts of species at survey sites. Single-visit estimation methods ignore spatial and temporal variation in species detection probabilities related to survey or site conditions that may confound estimates of species richness. We used simulated and empirical data to evaluate the bias and precision of raw species counts, the limiting forms of jackknife and Chao estimators, and multispecies occupancy models when estimating species richness to evaluate whether the choice of estimator can affect inferences about the relationships between environmental conditions and community size under variable detection processes. Four simulated scenarios with realistic and variable detection processes were considered. Results of simulations indicated that (1) raw species counts were always biased low, (2) single-visit jackknife and Chao estimators were significantly biased regardless of detection process, (3) multispecies occupancy models were more precise and generally less biased than the jackknife and Chao estimators, and (4) spatial heterogeneity resulting from the effects of a site covariate on species detection probabilities had significant impacts on the inferred relationships between species richness and a spatially explicit environmental condition. For a real data set of bird observations in northwestern Alaska, USA, the four estimation methods produced different estimates of local species richness, which severely affected inferences about the effects of shrubs on local avian richness. Overall, our results indicate that neglecting the effects of site covariates on species detection probabilities may lead to significant bias in estimation of species richness, as well as the inferred relationships between community size and environmental covariates. PMID: 26552273 [PubMed - in process] 

18. Br Poult Sci. 2015 Nov 9. [Epub ahead of print] 

The influence of feeding crimped kernel maize silage on broiler production, nutrient digestibility and meat quality. 
Ranjitkar S(1), Karlsson AH(2), Petersen MA(2), Bredie WL(2), Petersen JS(3), Engberg RM(1). Author information: (1)a Department of Animal Science (Immunology & Microbiology) , Aarhus University , Tjele, Skejby , Aarhus , Denmark. (2)b Department of Food Science , University of Copenhagen , Frederiksberg C., Skejby , Aarhus , Denmark. (3)c SEGES , Skejby , Aarhus , Denmark. 1. 

Two experiments were carried out in parallel with male Ross 308 broilers over 37 d. An experiment with a total of 736 broilers was performed to study the effect of dietary inclusion of crimped kernel maize silage (CKMS) on broiler production and meat quality. Another study with 32 broilers was carried out from 21-25 d to investigate the inclusion of CKMS on nutrient digestibility. 2. In both trials, 4 dietary treatments were used: wheat based feed (WBF), maize based feed (MBF), maize based feed supplemented with 15% CKMS (CKMS-15) and maize based feed supplemented with 30% CKMS (CKMS-30). 3. Compared with MBF, the DM intakes of broilers receiving CKMS-15 and CKMS-30 respectively were numerically 7.5 and 6.2 % higher, and FCR were 6 and 12 % poorer (significant for CKMS 30%), although there were no significant differences in AME content between the three diets. At 37 d, the body weight of birds receiving 15% CKMS was similar to birds fed with MBF. However, the inclusion of 30% CKMS decreased broiler growth. Dietary supplementation with CKMS significantly reduced the apparent digestibility of phosphorus. The fat digestibility was significantly lower for CKMS-30 than for the other 3 diets. 4. Broiler mortality decreased significantly when CKMS was added to the diet. 5. The consumption of drinking water was significantly lower in all maize based diets as compared to WBF and was lowest in broilers fed CKMS-30. 6. An improved litter quality in terms of dry matter content and a lower frequency of foot pad lesions was observed with broilers supplemented with both dietary levels of CKMS. 7. The addition of CKMS to maize based diets increased juiciness, tenderness and crumbliness of the meat. 8. In conclusion, the dietary supplementation of 15% CKMS had no negative effect on broiler growth and positively influenced bird welfare in terms of mortality and foot pad health. Therefore, the addition of 15% CKMS to maize based diets is considered an advantageous feeding strategy in broiler production. PMID: 26551864 [PubMed - as supplied by publisher] 

19. Comp Biochem Physiol A Mol Integr Physiol. 2015 Nov 5. pii: S1095-6433(15)00283-4. doi: 10.1016/j.cbpa.2015.11.006. [Epub ahead of print] 

Circulatory changes associated with the closure of the ductus arteriosus in hatching emu (Dromaius novaehollandiae). 
Castilla L(1), Burggren W(1), Muirhead D(2), Nelson TC(3), Dzialowski EM(4). Author information: (1)Developmental Integrative Biology Research Group, Department of Biological Sciences, 1155 Union Circle #305220, University of North Texas, Denton, TX 76203, United States. (2)City of Hope, 1500 East Duarte Road, Duarte, CA 91010, United States. (3)Department of Biological Sciences, Kalamazoo College, Kalamazoo, MI 49008, United States. (4)Developmental Integrative Biology Research Group, Department of Biological Sciences, 1155 Union Circle #305220, University of North Texas, Denton, TX 76203, United States. Electronic address: 

In developing avian embryos, the right and left ductus arteriosi (DA) allow for a shunt of systemic venous return away from the lungs to the body and chorioallantoic membrane (CAM). Unlike in mammals where the transition from placental respiration to lung respiration is instantaneous, in birds the transition from embryonic CAM respiration to lung respiration can take over 24h. To understand the physiological consequences of this long transition we examined changes and DA morphological changes during hatching in the emu (Dromaius novaehollandiae), a primitive ratite bird. By tracking microspheres injected into a CAM vein, we observed no change in DA blood flow between the pre-pipped to internally pipped stages. Two hours after external pipping, however, a significant decrease in DA blood flow occurred, evident from a decreased systemic blood flow and subsequent increased lung blood flow. Upon hatching, the right-to-left shunt disappeared. These physiological changes in DA blood flow correspond with a large decrease in DA lumen diameter from the pre-pipped stages to Day 1 hatchlings. Upon hatching, the right-to-left shunt disappeared and, at the same time apoptosis of smooth muscle cells began remodeling the DA for permanent closure. After the initial smooth muscle contraction, the lumen disappeared as intimal cushioning formed, the internal elastic lamina degenerated, and numerous cells underwent regulated apoptosis. The DA closed rapidly between the initiation of external pipping and hatching, resulting in circulatory patterns similar to the adult. This response is most likely produced by increased DA constriction in response to increased arterial oxygen levels and the initiation of vessel remodeling. Copyright © 2015. Published by Elsevier Inc. PMID: 26549875 [PubMed - as supplied by publisher] 

20. BMC Res Notes. 2015 Nov 6;8:655. doi: 10.1186/s13104-015-1643-5.  

Development and characterization of microsatellite loci for common raven (Corvus corax) and cross species amplification in other Corvidae. 
Pruett CL(1), Wan L(2), Li T(3), Spern C(4), Lance SL(5), Glenn T(6), Faircloth B(7), Winker K(8). Author information: (1)Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA. (2)Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA. (3)Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA. (4)Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA. (5)Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, 29802, USA. (6)Department of Environmental Health Science, University of Georgia, Athens, GA, 30602, USA. (7)Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA. (8)University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA. 

BACKGROUND: A priority for conservation is the identification of endemic populations. We developed microsatellite markers for common raven (Corvus corax), a bird species with a Holarctic distribution, to identify and assess endemic populations in Alaska. RESULTS: From a total of 50 microsatellite loci, we isolated and characterized 15 loci. Eight of these loci were polymorphic and readily scoreable. Eighteen to 20 common ravens from Fairbanks, Alaska were genotyped showing the following variability: 3-8 alleles per locus, 0.25-0.80 observed heterozygosity (Ho), and 0.30-0.80 expected heterozygosity (He). All loci were in Hardy-Weinberg equilibrium and linkage equilibrium and many loci amplified and were polymorphic in related taxa. CONCLUSIONS: These loci will be used to identify endemic populations of common raven and assess their genetic diversity and connectivity. PMCID: PMC4636899 PMID: 26545581 [PubMed - in process]

Tuesday, 10 November 2015

The Condor, Volume 117: Issue 4. November 2015

The Condor

Volume 117, Issue 4. November 2015



Winter site fidelity and winter movements in Common Loons (Gavia immer) across North America

James D. Paruk, Michael D. Chickering, Darwin Long, Hannah Uher-Koch, Andrew East, Daniel Poleschook, Virginia Gumm, William Hanson, Evan M. Adams, Kristin A. Kovach and David C. Evers
Biodiversity Research Institute, Portland, Maine, USA

In many avian species, breeding site fidelity has been more thoroughly investigated than winter site fidelity, yet the latter may have a greater impact on survivorship. The Common Loon (Gavia immer) is an example of a species whose breeding site fidelity has been well established, but whether it exhibits winter site fidelity remains unknown. Because Common Loons primarily winter in marine waters off coastal shores, winter site fidelity has been challenging to document. We investigated winter site fidelity in Common Loons across North America using satellite transmitters, recaptures, and resightings of previously color-marked individuals. Color-marked adults returned in consecutive years to the same coastal wintering locations in California, Washington, Louisiana, Maryland, and Massachusetts, USA. We estimated adult annual apparent survival as 77% (0.48–0.93) and adult winter site fidelity as 85% (0.35–0.98). This finding has important conservation implications in the aftermath of recent marine oil spills; if Common Loons return to the same contaminated wintering areas annually, decreased fitness and survivorship could result in population-level effects.

Comparing models of Red Knot population dynamics

Conor P. McGowan

U.S. Geological Survey, Alabama Cooperative Fish and Wildlife Research Unit, School of Forestry and Wildlife Science, Auburn University, Auburn, Alabama, USA

Predictive population modeling contributes to our basic scientific understanding of population dynamics, but can also inform management decisions by evaluating alternative actions in virtual environments. Quantitative models mathematically reflect scientific hypotheses about how a system functions. In Delaware Bay, mid-Atlantic Coast, USA, to more effectively manage horseshoe crab (Limulus polyphemus) harvests and protect Red Knot (Calidris canutus rufa) populations, models are used to compare harvest actions and predict the impacts on crab and knot populations. Management has been chiefly driven by the core hypothesis that horseshoe crab egg abundance governs the survival and reproduction of migrating Red Knots that stopover in the Bay during spring migration. However, recently, hypotheses proposing that knot dynamics are governed by cyclical lemming dynamics garnered some support in data analyses. In this paper, I present alternative models of Red Knot population dynamics to reflect alternative hypotheses. Using 2 models with different lemming population cycle lengths and 2 models with different horseshoe crab effects, I project the knot population into the future under environmental stochasticity and parametric uncertainty with each model. I then compare each model's predictions to 10 yr of population monitoring from Delaware Bay. Using Bayes' theorem and model weight updating, models can accrue weight or support for one or another hypothesis of population dynamics. With 4 models of Red Knot population dynamics and only 10 yr of data, no hypothesis clearly predicted population count data better than another. The collapsed lemming cycle model performed best, accruing ~35% of the model weight, followed closely by the horseshoe crab egg abundance model, which accrued ~30% of the weight. The models that predicted no decline or stable populations (i.e. the 4-yr lemming cycle model and the weak horseshoe crab effect model) were the most weakly supported.

Will representation targets based on area protect critical resources for the conservation of the Tucuman Parrot?

Anna M. Pidgeon, Luis Rivera, Sebastian Martinuzzi, Natalia Politi and Brooke Bateman
Department of Forest and Wildlife Ecology, University of Wisconsin–Madison, Madison, Wisconsin, USAFacultad de Ciencias Agrarias, Universidad Nacional de Jujuy, CONICET, Jujuy, Argentina

The Tucuman Parrot (Amazona tucumana), which is restricted to Southern Yungas forest of Argentina and Bolivia, has not recovered from severe population declines in the 1980s. We assessed habitat conservation targets for this species and asked, “What constitutes the right target?” For species with small ranges, maximizing the proportion of the range under protection is an established strategy to safeguard against threats. However, designating an amount for protection based on range alone (i.e. a ‘representation target') may set a misguided conservation target if critical resources are not considered. We used an ensemble model (‘biomod2’) to map suitable breeding and nonbreeding habitat of the Tucuman Parrot based on environmental variables and key resources (breeding) or the species' occurrence (nonbreeding). Pino blanco (Podocarpus parlatorei) seeds are critical food for Tucuman Parrot nestlings, so we modeled the distribution of this tree as a proxy for potential breeding habitat. We then examined the adequacy of current habitat protection relative to representation targets and in light of known threats, including forest degradation and loss, and poaching. Overall, 17% of the 110,122 km2Southern Yungas is protected, which is close to the proportion recommended (the target; 22%), based on the ecoregion's size, for inclusion in a conservation network. Similarly, 26% of the 46,263 km2 of nonbreeding habitat is protected, also relatively successful at 71% of the target (36%). However, of the scant ~21,000 km2of breeding habitat, only 15% is protected, much less than the representation target (49%) recommended for maximizing the probability of population persistence. Poaching of nestlings further undermines the value of some nesting habitat in Bolivia. For Tucuman Parrots, increased enforcement of protection in Bolivia and protection of additional nesting habitat in Argentina are the most efficient ways to enhance persistence. Our results illustrate how habitat conservation targets based on area alone may be inadequate if important biological information is overlooked.

Wintering ecology of sympatric subspecies of Sandhill Crane: Correlations between body size, site fidelity, and movement patterns

Gary L. Ivey, Bruce D. Dugger, Caroline P. Herziger, Michael L. Casazza and Joseph P. Fleskes

International Crane Foundation, Bend, Oregon, USADepartment of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, USA Western Ecological Research Center, U.S. Geological Survey, Dixon, California, USA
Body size is known to correlate with many aspects of life history in birds, and this knowledge can be used to manage and conserve bird species. However, few studies have compared the wintering ecology of sympatric subspecies that vary significantly in body size. We used radiotelemetry to examine the relationship between body size and site fidelity, movements, and home range in 2 subspecies of Sandhill Crane (Grus canadensis) wintering in the Sacramento–San Joaquin Delta of California, USA. Both subspecies showed high interannual return rates to the Delta study area, but Greater Sandhill Cranes (G. c. tabida) showed stronger within-winter fidelity to landscapes in our study region and to roost complexes within landscapes than did Lesser Sandhill Cranes (G. c. canadensis). Foraging flights from roost sites were shorter for G. c. tabida than for G. c. canadensis (1.9 ± 0.01 km vs. 4.5 ± 0.01 km, respectively) and, consequently, the mean size of 95% fixed-kernel winter home ranges was an order of magnitude smaller for G. c. tabida than for G. c. canadensis (1.9 ± 0.4 km2 vs. 21.9 ± 1.9 km2, respectively). Strong site fidelity indicates that conservation planning to manage for adequate food resources around traditional roost sites can be effective for meeting the habitat needs of these cranes, but the scale of conservation efforts should differ by subspecies. Analysis of movement patterns suggests that conservation planners and managers should consider all habitats within 5 km of a known G. c. tabida roost and within 10 km of a G. c. canadensis roost when planning for habitat management, mitigation, acquisition, and easements.

Genetic structure of Greater Sage-Grouse (Centrocercus urophasianus) in a declining, peripheral population

Dawn M. Davis, Kerry P. Reese, Scott C. Gardner and Krista L. Bird
U.S. Fish and Wildlife Service, Portland, Oregon, USADepartment of Fish and Wildlife Sciences, University of Idaho, Moscow, Idaho, USA California Department of Fish and Wildlife, Sacramento, California, USA
Loss of suitable habitat and subsequent fragmentation of populations are recognized as important factors in the decline and extinction of many species because they result in smaller, more isolated populations with reduced genetic diversity. The Greater Sage-Grouse (Centrocercus urophasianus), having declined in distribution and abundance throughout its range, is a candidate species under the U.S. Endangered Species Act and a species of special concern in California. Because the relationships between dispersal, gene flow, and genetic structure are interrelated and affect the long-term persistence of Greater Sage-Grouse, we assessed the genetic structure and patterns of dispersal among Greater Sage-Grouse in a declining, peripheral population in northeastern California. We genotyped 19 microsatellite loci from 167 individuals from 13 leks and 20 individuals captured off lek. Greater Sage-Grouse in northeastern California appear to maintain gene flow and genetic diversity across the sampled region. Despite population declines and habitat loss, leks were not genetically differentiated. Our results showed significant isolation-by-distance among males, which suggests that male Greater Sage-Grouse are more philopatric than females. Spatial autocorrelation analysis revealed stronger spatial structuring for males than for females. Results from the corrected assignment index also confirmed female-biased dispersal, although differences between sexes were not significant. While more research is needed on the proximate and ultimate causes behind the patterns we observed, our results serve as an important step toward understanding genetic structure and patterns of sex-biased dispersal in Greater Sage-Grouse occupying the periphery of the species' geographic distribution.

Scalar considerations in population trend estimates: Implications for recovery strategy planning for species of conservation concern

Danielle M. Ethier and Thomas D. Nudds
Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada

Broad-scale population trends are often used to identify and list species of conservation concern and as baselines to surmise which recovery actions might arrest or reverse declines. It is therefore important that trends are quantified regionally, so that finer-scale assessments can be made about the plausible causes of declines and targeted conservation actions can be implemented. We estimated regional population trends for a grassland bird, the Bobolink (Dolichonyx oryzivorus), to compare with trends from provincial analyses used for risk assessment, to identify the regions contributing most substantially to population declines. We used 45 yr of count data from the North American Breeding Bird Survey, across 35 agricultural census divisions in southern Ontario, Canada, to develop spatially explicit hierarchical Bayesian models of regional population trends. Population trends were negative in 30 of 35 census divisions, 6 of which had 95% credibility intervals (CI) that did not include zero. In 34 of 35 census divisions, the CI included the provincial short-term recovery goal of a population trend of −1%. Between 1998 and 2011, corresponding to the time series used for provincial risk assessment, the CI for 3 of 21 negative trends did not include 0 or −1. Our results indicate that most regional trend estimates currently exceed the goal set out in the recovery strategy, insofar as they have been stable and not necessarily declining. This suggests a more optimistic picture of the state of Bobolink population trends than that obtained from analyses at broader spatial scales, which masked important regional variation. This result demonstrates the need for consideration of scale variance in trend estimation during risk assessment and management planning, and the application of spatially explicit trend estimation for small geographic areas to aid in this process.

Summer vs. winter: Examining the temporal distribution of avian biodiversity to inform conservation

Kristen E. Dybala, Melanie L. TruanAndrew Engilis
Point Blue Conservation Science, Petaluma, California, USAMuseum of Wildlife and Fish Biology, Department of Wildlife, Fish & Conservation Biology, University of California, Davis, California, USA

Winter habitat quality plays a key role in avian population regulation, and conservation of winter habitat is a priority for waterfowl, shorebirds, and Neotropical migrant landbirds. Yet, there has been little discussion of the importance of conserving temperate wintering habitat for landbirds, including the billions of Neotemperate migratory landbirds that winter in the United States. The value and impact of conservation initiatives in the U.S. could be maximized by accommodating the habitat requirements of bird communities throughout the full annual cycle, particularly in the southern and western U.S. where winter species richness is concentrated. To estimate the degree to which winter bird communities should be a conservation priority, we examined the temporal distribution of avian diversity using riparian habitat in the lower Cosumnes River and lower Putah Creek watersheds in California's Central Valley. We used hierarchical multispecies occupancy models to estimate seasonal species richness and phylogenetic diversity in each watershed. We found that total species richness was equally as high in winter as in summer, and that phylogenetic diversity was higher in winter, with a considerable proportion of the winter avian diversity attributable to boreal-breeding Neotemperate migrants. Our results provide evidence that maintaining and restoring high-quality riparian habitat for winter bird communities in California is an important conservation opportunity. Broader recognition of the diversity of temperate winter bird communities and additional research into the factors affecting body condition and survival would facilitate effective conservation of high-quality winter habitat, benefiting Neotemperate migrants and year-round residents during a season that can have important impacts on their population dynamics.

Biases in nest survival associated with choice of exposure period: A case study in North American upland game birds

Erik J. Blomber, Daniel Gibson and James S. Sedinger
Department of Wildlife Ecology, University of Maine, Orono, Maine, USAProgram in Ecology, Evolution and Conservation Biology, Department of Natural Resources and Environmental Science, University of Nevada Reno, Reno, Nevada, USA
Estimated probability of daily nest survival is commonly used to derive cumulative nest survival for a specified nest-exposure period. For many species of birds, the presence of a parent is an important cue used by researchers to locate nests, but in some cases nest detection rates are reduced during egg laying, when parents spend a greater amount of time away from the nest. As a result, sample size becomes limited during the laying stage. Researchers must then choose between 2 alternative strategies for deriving cumulative nest survival, based on either (1) exposure length for only the incubation period or (2) exposure length for laying plus incubation. Both approaches carry implicit assumptions, the violation of which can result in bias. We reviewed recent literature and describe the extent to which these 2 strategies were used in studies of galliform birds (including grouse, quail, and Wild Turkey [Meleagris gallopavo]) in North America. We then evaluated the theoretical potential for bias under each approach across a range of daily nest survival probabilities and for 3 different life-history scenarios. The incubation-only strategy was most commonly applied, with 62% of publications reporting its use. We found that the incubation-only strategy was biased except under an assumption of zero nest failure during egg laying. Fewer studies reported using the laying-plus-incubation strategy, which was unbiased in situations where risk of failure was equivalent among laying and incubation stages. This strategy also minimized bias across the broadest range of situations, and accordingly we recommend its use where the daily survival rate during egg laying is unknown. We recommend that both the laying and incubation periods should be used to define the length of nest exposure when estimating cumulative nest survival, particularly for species with large clutches and long laying periods.

Physical, human disturbance, and regional social factors influencing Common Loon occupancy and reproductive success

Maxwell Field and Thomas M. Gehring
Department of Biology, Central Michigan University, Mount Pleasant, Michigan, USA

Common Loons (Gavia immer) appear to use physical habitat, human disturbance, and social cues when selecting territories; however, recent loon habitat models suggest that the importance of each of these cues may vary depending on population density. We conducted loon detection surveys on lakes (n = 42) in the Lower Peninsula of Michigan, USA, during 2007–2008, and developed territory occupancy and nest success models. We found that occupancy was positively associated with lake area and the presence of islands, whereas road density (human disturbance) and the number of loon pairs within 10 km (social cue) were not important predictors of occupancy. Similarly, loon nest success was positively associated with lake area and the presence of islands. Both models performed well when applied to an independent dataset of 85 lakes (AUC = 0.743 and 0.724, respectively), indicating that these models could be used for identifying suitable habitat during conservation efforts. Our results suggest that managers should first focus efforts on maintaining or creating nesting islands on lakes, and then assess regional loon occupancy rates once physical habitat conditions are met. Comparing our results with recent loon habitat models, we suggest that social cue covariates are most important at low population densities, whereas physical habitat covariates are dominant predictors of occupancy at higher population densities of loons. Loon response to human disturbance appears to be location-specific, depending on the level of human development around lakes and local conservation efforts, particularly the provision of artificial nest platforms.

Using local dispersal data to reduce bias in annual apparent survival and mate fidelity

Caz M. Taylor, David B. Lank and Brett K. Sandercock

Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, USACentre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, CanadaDivision of Biology, Kansas State University, Manhattan, Kansas, USA


In mark–recapture studies conducted on fixed-area study sites, apparent (or “local”) survival (ϕ) is the product of the probabilities of true survival (S) and site fidelity to the sampling area (F). If marked individuals permanently emigrate from the study site, apparent survival will be biased low relative to true survival. Similarly, estimates of mate fidelity will be biased high because site fidelity is typically higher for individuals that reunite with their previous mates than among pairs that divorce. Here, we develop a method for calculating site fidelity that takes plot boundaries into account, based on a dispersal model estimated from local movements within a fixed study site. We use dispersal estimates to adjust apparent survival and mate fidelity for the effects of short-distance movements out of a fixed area. We demonstrate our method with a retrospective analysis of a published study of 2 species of sandpipers breeding sympatrically at a field site in western Alaska. Estimates of survival probability increased by 0.01–0.03 for males and 0.07–0.08 for females in both species. The larger adjustments for females were expected based on their longer local dispersal movements. Adjusted mate fidelity estimates were lower than the original estimates by 0.04–0.07. Use of local movement data to estimate site fidelity cannot account for permanent emigration due to long-distance movements and, if such movements occur, our adjusted estimates of ϕ remain a function of true survival and site fidelity. Nevertheless, our method can reduce bias in demographic parameters resulting from local dispersal movements, improving estimates of annual survival and mate fidelity for use in demographic models.

Habitat selection, nest survival, and nest predators of Rusty Blackbirds in northern New England, USA

Shannon H. Buckley Luepold, Thomas P. Hodgman, Stacy A. McNulty, Jonathan Cohen and Carol R. Foss

Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York, USA
Bird Group, Maine Department of Inland Fisheries and Wildlife, Bangor, Maine, USA
Adirondack Ecological Center, State University of New York College of Environmental Science and Forestry, Newcomb, New York, USA
Audubon Society of New Hampshire, Concord, New Hampshire, USA

Rusty Blackbird (Euphagus carolinus) populations have plummeted since the mid-20th century. Recent research in New England, USA, suggests that an ecological trap, created through timber harvesting on the breeding grounds, may be responsible. Red squirrels (Tamiasciurus hudsonicus) were hypothesized to be the primary nest predator, but definitive identification was lacking. The potential for mast cone crops to affect Rusty Blackbird nest predation via trophic interactions also remains unexamined. Our objectives were to identify the mechanisms by which an ecological trap may be operating in New England through a multiscale analysis of Rusty Blackbird habitat selection and nest survival, as well as predator identification and quantification. We located 72 Rusty Blackbird nests in Maine and New Hampshire in 2011 and 2012, and modeled habitat selection and nest survival as a function of habitat characteristics at the nest patch (5 m) and home range (500 m) scale. We placed camera traps at 29 nests to identify nest predators, and conducted ground surveys to obtain an index of squirrel abundance each year. We found that Rusty Blackbirds selected nest patches with a high basal area of small conifers and low canopy closure. Nest survival was not reduced in harvested stands, but increased with increasing basal area. Percent cover of wetlands and young softwood stands were the best predictors of Rusty Blackbird selection at the home range scale. At the home range scale, we found that nests that were closer to a road were less successful in 2011, but not in 2012. Red squirrels were the most frequent predator of Rusty Blackbird nests in 2012, when they were abundant following a mast year in 2011. These results suggest that dense cover of small softwoods is important for habitat selection and survival of Rusty Blackbird nests, and that precommercial thinning and possibly road-building could reduce habitat quality for this species.

Can interrupting parent–offspring cultural transmission be beneficial? The case of Whooping Crane reintroduction

Vladimir Dinets

Psychology Department, University of Tennessee, Austin Peay Building, University of Tennessee, Knoxville, Tennessee, USASchool of Renewable Natural Resources, Louisiana State University, Baton Rouge, Louisiana, USA
Inheriting behavioral patterns culturally (i.e. by learning from parents) rather than genetically is considered an integral part of individual development for many bird and mammal species. I discuss the possibility that in some cases, particularly when only heavily modified habitat remains available, such transmission might have a negative effect on the individual's adaptability and chances of survival. Instead, animals deprived of normal parental care may be better suited for survival in novel environments. I describe this possible scenario with captive-reared Whooping Cranes (Grus americana) released in southwestern Louisiana, primarily in the context of human-modified habitats used by this reintroduced population. Captive-rearing techniques based on this approach may be beneficial for other threatened species, particularly those that have little or no nonmodified habitat left and are amenable to alternative habitats if cultural transmission is interrupted.

Understanding the distribution of a threatened bird at multiple levels: A hierarchical analysis of the ecological niche of the Santa Marta Bush-Tyrant (Myiotheretes pernix)

Esteban Botero-Delgadillo, Nicholas J. Bayly, Sandra Escudero-Páez and María Isabel Moreno

Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, ChileSELVA: Investigación para la Conservación en el Neotrópico, Bogotá D.C., Colombia
An understanding of the ecological factors determining bird species' distributions is essential for making informed conservation decisions. These data are especially important for range-restricted species, such as the Santa Marta Bush-Tyrant (Myiotheretes pernix), a threatened endemic of the Sierra Nevada de Santa Marta (SNSM) in Colombia. Here we adopt a novel hierarchical analysis to describe the bush-tyrant's ecological niche and infer the regional and local determinants of its limited distribution. We first describe habitat selection based on local habitat use and microhabitats used for foraging. We then use a geoprocessing modeling algorithm to combine habitat selection data with a climatic niche model. The resulting model produced an index of habitat suitability, which we converted into a predicted geographic distribution. Santa Marta Bush-Tyrants showed no clear habitat preferences, but favored forested and secondary growth habitats over open areas, at elevations between 2,100 and 3,300 m. The species' predicted distribution was restricted to the northern flanks of the SNSM, with an estimated extent of ~352 km2. This estimate is more restricted than previous estimates (570 km2), but does not alter the species' status as Endangered based on IUCN criteria. The model predicted that the presence of Santa Marta Bush-Tyrants was regionally dependent on cold and humid climates, with low annual variation in temperature and precipitation. Locally, the species' presence was determined by the availability of habitat edges between forests and open areas. Conservation actions should aim to reduce rates of forest loss, while maintaining the presence of areas with good light and exposed perches, microhabitat conditions typically found in habitat edges or areas of natural disturbance. An explicit integration of quantitative data on habitat use and foraging patterns into niche models would help to obtain more realistic and detailed projections of the occupied distribution of range-restricted birds.

Morphometrics of mid-Atlantic dabbling ducks for use in thermoregulation models

Mark C. Livolsi, Christopher K. Williams, John M. Coluccy and Matthew T. DiBona

Department of Entomology and Wildlife Ecology, University of Delaware, Newark, Delaware, USADucks Unlimited Inc., Ann Arbor, Michigan, USADelaware Department of Natural Resources and Environmental Control, Division of Fish & Wildlife, Dover, Delaware, USA
Bioenergetics modeling is a popular tool used by waterfowl biologists to estimate carrying capacity based on food energy availability and daily energy expenditure (DEE). For wintering waterfowl, estimates of DEE may incorporate a cost of thermoregulation (CT) component, which accounts for metabolic heat production when ambient temperatures fall below a species-specific Lower Critical Temperature (LCT). Typically, DEE estimates have utilized either a fixed CT component or a simple CT model based solely on the magnitude of the difference between ambient temperature and LCT. Using a more complex CT model that accounts for differential heat loss from individual body regions due to temperature, wind speed, and contact with air or water may provide more detailed estimates of CT and, in turn, carrying capacity. However, such models required detailed morphometrics as model inputs in addition to environmental data. We present morphometrics for 8 dabbling duck species for use in thermoregulation models, as well as regression equations that may substitute for measurements of unmeasured species. We compared CT values produced via simple and complex CT models for American Black Ducks (Anas rubripes) wintering on the Delaware Bayshore, 2011–2013. We found that the complex CT model produced significantly higher CT estimates (5.38 ± SE 0.38 kJ bird−1 hr−1) compared with the simple model (1.26 ± 0.04 kJ bird−1 hr−1). Applying these CT values to bioenergetics models for American Black Ducks wintering in southern New Jersey suggested that this disparity in CT could produce substantial differences in estimated carrying capacity. Thus, we recommend that researchers consider incorporating detailed CT models into their estimates of DEE to reduce bias in carrying capacity estimates.

Anthropogenic features influencing occurrence of Black Vultures (Coragyps atratus) and Turkey Vultures (Cathartes aura) in an urban area in central Amazonian Brazil

Weber G. Novaes and Renato Cintra

WGN Environmental Consulting, Lauro de Freitas, Bahia, BrazilGraduate Program in Ecology, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, BrazilCoordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil
Recent increases in Black Vulture (Coragyps atratus) and Turkey Vulture (Cathartes aura) numbers, particularly in urban–suburban settings, have led to more frequent human–vulture interactions, including vulture–aircraft strikes. This problem highlights the need for vulture management strategies, including determining habitat use by these species in urban settings. We investigated the effects of structures and landscape features on habitat use by Black and Turkey vultures in and around the city of Manaus in central Amazonian Brazil. We repeatedly surveyed 80 sites (3–9 visits per site in 2009–2010) and used detection histories to derive maximum-likelihood estimates of (1) vulture occurrence and detection probabilities and (2) environmental covariate effects on occupancy. Hierarchical logistic models showed that Black Vultures were associated with urban features such as open garbage containers and streams, but Turkey Vultures were associated with forest fragments. These results suggest that Black Vultures select environments where the food supply is abundant, whereas Turkey Vultures may avoid sites that attract Black Vultures in favor of forest remnants, a habitat for which they have specific foraging adaptations. Black Vulture management should focus on reducing the amount of food waste available to the birds in urban open garbage containers and streams, but Turkey Vulture management could be improved through removal of animal carcasses, and perhaps also removal of nests and roosts from forest remnants, especially near airfields.

Genetic structure, diversity, and interisland dispersal in the endangered Mariana Common Moorhen (Gallinula chloropusguami)

Mark P. Miller, Thomas D. Mullins, Susan M. Haig, Leilani Takano and Karla García

U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon, USAU.S. Fish and Wildlife Service, Honolulu, Hawaii, USA
The Mariana Common Moorhen (Gallinula chloropus guami) is a highly endangered taxon, with fewer than 300 individuals estimated to occur in the wild. The subspecies is believed to have undergone population declines attributable to loss of wetland habitats on its native islands in the Mariana Islands. We analyzed mitochondrial DNA (mtDNA) sequences (control region and ND2 genes) and nuclear microsatellite loci in Mariana Common Moorhens from Guam and Saipan, the two most distal islands inhabited by the subspecies. Our analyses revealed similar nuclear genetic diversity and effective population size estimates on Saipan and Guam. Birds from Guam and Saipan were genetically differentiated (microsatellites: FST = 0.152; control region: FST = 0.736; ND2: FST = 0.390); however, assignment tests revealed the presence of first-generation dispersers from Guam onto Saipan (1 of 27 sampled birds) and from Saipan onto Guam (2 of 28 sampled birds), suggesting the capability for long-distance interpopulation movements within the subspecies. The observed dispersal rate was consistent with long-term estimates of effective numbers of migrants per generation between islands, indicating that movement between islands has been an ongoing process in this system. Despite known population declines, bottleneck tests revealed no signature of historical bottleneck events, suggesting that the magnitude of past population declines may have been comparatively small relative to the severity of declines that can be detected using genetic data.

Patterns of migratory connectivity in Vaux's Swifts at a northern migratory roost: A multi-isotope approach

Matthew W. Reudink, Steven L. Van Wilgenburg, Lauren S. Steele, Andrew G. Pillar, Peter P. Marra and Ann E. McKellar

Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, CanadaEnvironment Canada, Saskatoon, Saskatchewan, CanadaMigratory Bird Center, Smithsonian Conservation Biology Institute, Washington, D.C., USA

The strength of migratory connectivity between breeding, stopover, and wintering areas can have important implications for population dynamics, evolutionary processes, and conservation. For example, patterns of migratory connectivity may influence the vulnerability of species and populations to stochastic events. For many migratory songbirds, however, we are only beginning to understand patterns of migratory connectivity. We investigated the potential strength of migratory connectivity within a population of Vaux's Swifts (Chaetura vauxi). Like many aerial insectivores, this species is currently experiencing population declines. In 2012, a mass mortality event at a spring migratory roost on Vancouver Island, British Columbia, Canada, resulted in the deaths of >1,000 individuals (~2% of the British Columbia population). In these individuals, we examined variation in 3 stable isotopes (δ2H, δ13C, and δ15N) from claw samples to determine whether spring migrants showed inherent isotopic similarity in the habitats they used on their Mexican and Central American wintering grounds. Our results indicated the presence of 2 or 3 broad isotopic clusters, which suggests that Vaux's Swifts that migrated through Vancouver Island most likely originated from 2 or 3 overwintering locales or habitat types. We found no evidence of sex- or morphology-based segregation, which suggests that these groups likely share a similar overwintering ecology and, thus, may be equally vulnerable to stochastic events or habitat loss on the wintering grounds. Our results highlight the need for more studies on the nonbreeding-season ecology and migratory connectivity of this species.