bluuebunny/crossref_metadata_2025_split huggingface dataset:
What Makes a Good Nest? Benefits of Nest Choice to Female Baya Weavers (Ploceus Philippinus)
Authors: Quader Suhel 
Published: September 2019

Abstract
The nests of some birds are built exclusively by males and then displayed to females. In such species, one expects females to choose those nests that provide maximum safety to themselves and their offspring. What attributes of a nest should females use in making these choices? Here, I examine the correlates of nesting success in the Baya Weaver (Ploceus philippinus), a species in which males provide nests and little else. In particular, I examine which of two suites of nest attributes best predicts nesting success: nest location (which reflects male competitive ability) or nest architecture (which reflects male building skill). Because whether a nest has successfully fledged young is sometimes uncertain, I supplement generalized linear model analyses with survival analyses, which can incorporate ambiguity in nest fate. Together, these analyses reveal that nests built in thorny trees and woven with fine fiber have high success. Nesting success also increases with nest height and with thickness of the supporting branch. Overall, nest location is a slightly better predictor of success than nest architecture; this is consistent with previous findings that female choice of nests is influenced more by location than by architecture.
¿Qué Hace a un Nido un Buen Nido? Beneficios de la Selección de Nidos para las Hembras en Ploceus philippinus
A Molecular Phylogeny of Kingfishers (Alcedinidae) With Insights Into Early Biogeographic History
Authors: Moyle Robert G. 
Published: September 2019

AbstractThe phylogeny of kingfishers was reconstructed by comparing mitochondrial and nuclear DNA sequences representing 38 ingroup species. Analysis of the combined data and the nuclear data alone recovered the Alcedininae as the basal lineage in the family. This basal arrangement, and support for many relationships within the three subfamilies, allows discussion of biogeographic issues. The Australian region and Pacific islands display the highest diversity of kingfishers, but this diversity is not a reflection of a long history in the region. Rather, high diversity and endemism in the Australian region is inferred to result from relatively recent radiations from southern Asia. The most parsimonious explanation for the origin of New World taxa is two dispersal events from the Old World. Within the large Halcyon radiation, the phylogeny is well resolved and allows evaluation of generic assignments. The phylogeny supports splitting Todiramphus from Halcyon. Todiramphus and Syma are sister taxa, as are Halcyon and Pelargopsis. Thus, merging or retaining those genera is a more subjective decision. Although not fully resolved, relationships within the alcedinines indicate that Ceyx and Alcedo, as currently delimited, are not natural groups.Phylogénie Moléculaire des Alcedinidae avec un Aperçu de l'Histoire Biogéographique Ancienne
Tracking Dispersal in Birds: Assessing the Potential of Elemental Markers
Authors: Donovan Therese , Buzas Jeffrey , Jones Peter , Lisle Gibbs H. 
Published: September 2019

AbstractNatal dispersal in vagile species such as songbirds can shape a population's range and structure. Although effective conservation practices depend on knowledge of the scale and frequency of natal dispersal, these issues remain poorly understood because of methodological gaps. In this exploratory study, we assessed whether element signatures within natal feathers might be used to identify the geographic birth site of first-year breeders. We used two related techniques, inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma with optical emission spectrometry (ICP-AES), to quantify element levels in natal feather samples from 7 species at 27 sites across the eastern United States. The techniques differed in the manner in which elements were quantified and in their detection limits. Our goal was to determine whether element analyses of feathers could discriminate (1) different species within a site and (2) different sites within a species. Additionally, because spatial autocorrelation of element levels is needed for element analysis to be an effective tool in assessing natal dispersal, we also evaluated the spatial autocorrelation of ICP-AES samples at 18 sites across the eastern United States.Both ICP-MS and ICP-AES analyses separated species within a site with fairly high accuracy, though the discriminating elements varied with site. However, within a species, natal feather locations were not identified with high accuracy on the basis of feather elements. We were not able to determine whether there is spatial correlation among individual elements or a principal component analysis (PCA) score that described the elemental makeup of a feather. A kriging model was fit to the semivariogram of PCA scores to produce a base-map of element signatures across the eastern United States. This map was ineffective at predicting feather-element values at sample sites. Whether elemental analyses can identify natal dispersal distances requires further study. We suggest that future studies evaluate elements with ICP-MS methodologies on a single, box-nesting species that is sampled more intensively at smaller geographic scale, or on species that occur in very discrete populations. Additionally, this methodology should be evaluated in concert with stable-isotope analyses of feathers and, potentially, genetic analyses.Suivre la Dispersion chez les Oiseaux: Évaluer le Potentiel de Marqueurs Élémentaires
Do Partial and Regular Migrants Differ in Their Responses to Weather?
Authors: Nilsson Anna L. K. , Alerstam Thomas , Nilsson Jan-Åke 
Published: September 2019

AbstractPartial migration is often considered a transitory stage between migration and residency, and whether partial migrants take weather conditions into account during migration is largely unknown. To assess whether partial migrants differ from regular migrants in their responses to weather, we compared the migratory intensity of a partial migrant, the Blue Tit (Cyanistes caeruleus), with more regular migrants in relation to weather at a migratory passage site in southern Sweden (Falsterbo) during the years 1993–2002. The regular migrants in the study were Linnet (Carduelis cannabina), Common Chaffinch (Fringilla coelebs), Brambling (F. montifringilla), and European Robin (Erithacus rubecula). The Blue Tit differed from the regular migrants mainly in showing a striking negative correlation between migratory activity and cloud cover. Also, weather had the highest explanatory power for migratory intensity in the Blue Tit. This suggests that the Blue Tit is more sensitive to weather conditions on migration than the regular migrants and that it preferably awaits days with wholly or partly clear skies before migrating past Falsterbo. As a consequence, Blue Tits usually restrict their migratory flights to the safest occasions, with relatively calm weather, good visibility, and all orientation cues (solar as well as magnetic) available.¿Difieren los Migrantes Parciales y Regulares en sus Respuestas al Clima?
Testosterone Treatment to Free-Ranging Male Dark-Eyed Juncos (Junco Hyemalis) Exacerbates Hemoparasitic Infection
Authors: Deviche Pierre , Parris Jennifer 
Published: September 2019

AbstractThe “immunocompetence handicap” hypothesis predicts that reproductive hormones, in particular testosterone (T), are immunosuppressive and consequently increase susceptibility to diseases and parasite infections, but this prediction has not been evaluated in free-living birds and the factors mediating the immunosuppressive influence of T remain poorly known. To address these issues, we administered supplemental T via implants to free-ranging adult male Dark-eyed Juncos (Junco hyemalis) and characterized the effects of this treatment on infection with the two most prevalent hematozoan parasites in this species, Leucocytozoon fringillinarum and Trypanosoma avium. Males caught at the beginning of their breeding season (May) received T-filled, empty (control), or no Silastic capsules, and were recaptured five weeks later. Capsule implantation had, by itself, no effect on parasite infections, body mass, or size of an androgen-dependent secondary sexual characteristic, the cloacal protuberance. Testosterone treatment maintained physiologically high plasma levels of the steroid for the duration of the study, thus preventing the seasonal decline in these levels that occurred in control males. As predicted by the immunocompetence handicap hypothesis, the hormone treatment increased blood L. fringillinarum abundance. This increase was specific, in that implanted T did not affect (1) either the prevalence or the incidence of L. fringillinarum, (2) body mass, or (3) size of the cloacal protuberance. Trypanosoma avium prevalence was not influenced by T treatment either, but it increased between May and June, which suggests that it is regulated by factors other than the activity of the reproductive system. These findings provide the first demonstration in free-ranging birds that experimentally elevated physiological T levels increase hematozoan infection.El Tratamiento de Testosterona en Machos Silvestres de Junco hyemalis Exacerba la Infección de Hemoparásitos
Landscape-Scale Physiology: Site Differences in Refueling Rates Indicated by Plasma Metabolite Analysis in Free-Living Migratory Sandpipers
Authors: Seaman Dana A. Acevedo , Guglielmo Christopher G. , Elner Robert W. , Williams Tony D. 
Published: September 2019

Abstract
Variation in plasma metabolite profiles can provide information on physiological state and relative rates of mass change in free-living birds caught only once, and this technique could be used to compare rates of mass change (fattening) among populations or sites in relation to habitat quality. We compared plasma metabolite levels, as an index of relative refueling rates, in migratory Arctic-nesting Western Sandpipers (Calidris mauri), on a landscape scale at as many as nine sites over two years and during three different migratory stages within the Georgia Basin-Puget Sound region of British Columbia and Washington. There was significant intersite variation in plasma triglyceride levels in both years, but only for the northward migration. By contrast, there was little evidence of intrasite variability (i.e. metabolite profiles of birds using the same site were consistent between years and migratory stages), though we documented intrasite variation resulting from birds' use of different microhabitats at the same site. Plasma glycerol levels did not vary systematically among sites, though they varied among years; on average, birds had higher glycerol levels during northward migration than during southward migration. For the northward migration only, there was a positive relationship between plasma triglyceride levels and total macrofaunal prey abundance among sites. Birds using smaller sites with a lower index of mudflat exposure (mean number of kilometer-hours of mudflat exposed in a 24-h period, reflecting the opportunity to forage at each site) tended to have lower triglyceride levels.
Fisiología a Escala de Paisaje: Diferencias entre Sitios en las Tasas de Reabastecimiento Indicadas por Análisis de Metabolitos del Plasma en Chorlos Migratorios Silvestres
Estimating Detection Probablities of River Birds using Double Surveys
Authors: Fletcher Robert J. , Hutto Richard L. 
Published: September 2019

AbstractWe describe a method for surveying birds in river habitats that allows for rapid assessment across broad spatial scales and estimation of detection probabilities. Our river survey approach incorporates a double-survey technique, whereby observers in two canoes simultaneously survey birds along a river reach. Data are in the form of a two-sample mark-recapture history, and covariates suspected of influencing detection probabilities can be included in the modeling process and evaluated using information-theoretic approaches. We provide an example using the method along the Madison and upper Missouri rivers in Montana. Overall, detection probabilities for each observer ranged from 57% to 89%, and combined detection probabilities (the likelihood of at least one observer detecting an individual) were consistently high (88% across all species). Detection probabilities across species were positively correlated with body mass. Detection probabilities for some species were influenced by observer, river conditions, and whether species were in groups or alone; groups were more detectable, and individuals in slow-flowing and wide sections of river were more detectable. Boat-based double surveys are a viable method for estimating detection probabilities of birds in river habitats, and double surveys should be considered in other aquaticEstimaciones de Probabilidades de Detección de Aves de Río Utilizando Muestreos Dobles systems.
Growth and Allocation in Captive Common Murre (Uria Aalge) Chicks
Authors: Benowitz-Fredericks Z Morgan , Kitaysky Alexander S. , Thompson Christopher W. 
Published: September 2019

AbstractIn birds, relative growth rates of morphological characters change in response to restricted food intake during development. Differential allocation of limited resources is hypothesized to reflect functional priorities for developing chicks. Body mass, wing, and flight feathers have been identified as potential priorities for seabird chicks. We used allometry to examine allocation in captive Common Murre chicks fed within a range of natural provisioning. During days 10–45 post-hatch, chicks were fed one of four diets that varied in biomass, energy content, and composition. Energy intake had a more profound effect on growth and development than diet composition; it significantly reduced absolute growth of body mass, manus, and tarsus. Between day 15 and day 20, allocation changed in all treatments: growth of manus was maintained at the expense of body mass. Chicks in more restricted treatments shifted allocation to manus at a lower body mass than those in less restricted groups, but subsequently allocated similarly. Wing loading was higher for chicks than for adult alcids, but scaled similarly. Growth of primary feathers was the most sensitive to small differences in diet composition. Our data also suggest that some changes in allocation may be ontogenetically determined rather than part of an adaptive response to reduced food intake.Croissance et Allocation chez des Oisillons Uria aalge
Breeding Biology and Success of a Reintroduced Population of the Critically Endangered Puaiohi (Myadestes Palmeri)
Authors: Tweed Erik J. , Foster Jeffrey T. , Woodworth Bethany L. , Monahan William B. , Kellerman Jherime L. , Lieberman Alan 
Published: September 2019

AbstractThe ultimate success of reintroduction programs for endangered species depends on the ability of reintroduced animals to breed in the wild. We studied the nesting success and breeding biology of a reintroduced population of Puaiohi (Myadestes palmeri) on the island of Kaua'i, Hawaii. Thirty-four captive-bred Puaiohi were released into the Alaka'i Swamp in 1999-2001 and monitored using radiotelemetry. Ten females and two males paired with wild and other released birds, including one polygynous trio. From March to September, 31 nests were built. Mean clutch size was 2.0 eggs, daily nest survival was 0.97 ± 0.01 (mean ± SE) and overall nest success was 0.40 ± 0.02. We confirmed predation, most probably by rats (Rattus spp.), as the greatest cause of nest failure, occurring at 38% of active nests with known fates, and causing the death of two nesting adult females. Ground-based rodent control proved ineffective at protecting nest attempts. Successful nests fledged an average of 1.4 young each (n = 10), and 85% of fledglings survived at least two weeks. Importantly, breeding behavior and success were comparable to those of wild Puaiohi. This is the first record of breeding in the wild from captive-bred endangered Hawaiian passerines. The ability of captive-bred Puaiohi to survive and breed successfully in the wild bodes well for future releases of this and other endangered passerines, but high predation rates on nests and nesting females highlights the importance of maintaining and restoring safe habitat for recovery.Biología y Éxito Reproductivo de una Población Reintroducida de Myadestes palmeri, una Especie en Peligro Crítico
Nest Depredation, Brood Parasitism, and Reproductive Variation in Island Populations of Song Sparrows (Melospiza Melodia)
Authors: Wilson Scott , Arcese Peter 
Published: September 2019

AbstractTheory suggests that the persistence of metapopulations will be influenced by the degree of synchrony in the dynamics of their component populations. Various studies have shown that climate can promote synchrony in the size of adjacent populations linked by dispersal, but fewer studies have examined the effects of climate on underlying demographic rates. We studied annual variation in the timing of breeding and reproductive rates in Song Sparrow (Melospiza melodia) on islands linked by dispersal to determine whether biotic factors acting at local scales or climatic factors acting at a regional scale were more influential of variation in demography. The onset of egg laying varied markedly among years but was roughly synchronous across islands within years. Despite this synchrony, island populations varied markedly in reproductive rate, mainly from spatial variation in nest depredation and brood parasitism. In general, populations farther from Vancouver Island and with fewer resident predators experienced less nest depredation and brood parasitism, and higher reproductive rates, than populations closer to Vancouver Island. Our results show that even when climate acts regionally to synchronize reproductive timing in adjacent populations, its effects on reproductive rate may be overridden by biotic factors that vary among populations.Depredación de Nidos, Parasitismo de Cría y Variación Reproductiva en Poblaciones Isleñas de Melospiza melodia
Within-Territory Habitat Use and Microhabitat Selection by Male Cerulean Warblers (Dendroica Cerulea)
Authors: Barg Jennifer J. , Aiama Deviah M. , Jones Jason , Robertson Raleigh J. 
Published: September 2019

Abstract
Although most habitat characteristics are known to be continuously variable in space, practicality dictates that most habitat-selection studies at the spatial scale of the territory treat within-territory habitat as essentially homogeneous. However, the limitations associated with such a compromise have remained largely unexamined. Male Cerulean Warblers (Dendroica cerulea) exhibit nonrandom space- use patterns within their territories, in that all territories contain areas of intensive use or core areas. In addition to documenting territory-wide habitat and behavioral use patterns in this species, we asked two specific questions about core-area structure and function. (1) Are core-area habitats distinct in their vegetative composition and structure from the rest of the territory? (2) What behavioral mechanisms underlie the nonrandom space-use patterns? On a territory-wide basis, males used trees in proportion to their availability; however, core areas were predominantly composed of bitternut hickory (Carya cordiformis), which was a highly preferred song-post tree. Core areas were not consistently associated with any other habitat feature, including canopy gaps. Core areas were singing centers; song-post densities within core areas were 10× higher than in noncore areas. In our study area, bitternut hickories have significant delayed leaf-out patterns, potentially offering minimal acoustic hindrance to song transmission until late in the breeding season. These singing centers may be strategically placed to simultaneously maintain vigilance over social nests and maximize communication with conspecifics. Core areas are potentially as important to males as nesting habitat is to females, and their provision should be taken into account when implementing conservation or management strategies.
Uso de Hábitat en los Territorios y Selección de Microhábitats por los Machos en Dendroica cerulea
Mixed-Grass Prairie Passerines Exhibit Weak and Variable Responses to Patch Size
Authors: Davis Stephen K. , Brigham R. Mark , Shaffer Terry L. , James Paul C. 
Published: September 2019

AbstractMuch of our current understanding of the demographic effects of habitat fragmentation on bird populations is derived from studies of passerines in forests and tallgrass prairie surrounded by woody vegetation. We quantified grassland bird density, nest survival, and productivity in 41 native mixed-grass prairie pastures during 1997-2000 in southern Saskatchewan, Canada. Pastures ranged in size from 18 ha to 11,600 ha and were typically surrounded by agriculture (i.e., ranching and annual cropping). Grassland passerines did not respond strongly or uniformly to patch size. Sprague's Pipit (Anthus spragueii) was the only species whose density increased with pasture size. Patch size had minimal influence on nest survival of Sprague's Pipit or Clay-colored Sparrow (Spizella pallida); whereas nest survival increased with patch size for Savannah Sparrow (Passerculus sandwichensis) and declined for Baird's Sparrow (Ammodramus bairdii), Chestnut-collared Longspur (Calcarius ornatus), and Western Meadowlark (Sturnella neglecta). Time-specific factors (i.e., nest age, date, and year) were more important predictors of nest survival than patch size. Exploratory analyses indicated that effects of edge distance, pasture shape, or landscape on nest survival were just as likely as patch-size effects. However, effects of edge on Chestnut-collared Longspurs may be governed by landscape-level factors, because nest survival decreased with distance to edge in landscapes with increased amounts of cropland. Our results indicate that mixed-grass prairie parcels ≥18 ha play a role in the conservation of several grassland passerine species currently in decline, but the conservation of Sprague's Pipit likely depends on maintaining larger tracts of native prairie.Les Passereaux des Prairies Herbacées Montrent des Réponses Faibles et Variables en Réponse à la Taille des Parcelles d'Habitats