bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gosling Growth and Survival in Relation to Brood Movements in Greater Snow Geese (Chen Caerulescens Atlantica)
Authors: Mainguy Julien , Gauthier Gilles , Giroux Jean-François , Bêty Joël 
Published: September 2019

AbstractPost-hatch brood movements to high-quality foraging sites are common in precocial birds but may entail costs for young. We assessed effects of overland movements of broods between the nesting and rearing areas in Greater Snow Geese (Chen caerulescens atlantica) breeding on Bylot Island, Nunavut, Canada, to determine whether these movements affected gosling survival and growth. We monitored 51 radiomarked females over five years to quantify movement distance, movement duration, and gosling survival. Gosling growth was compared over four years using a sample of web-tagged broods recaptured shortly before fledging among adults that (1) nested and reared their young in a dense colony, (2) left the colony and moved ≈30 km to reach the main brood-rearing area, or (3) nested and reared their young in the main brood-rearing area. Brood movements by radio-marked birds were highly variable (2.6-52.5 km, depending on rearing areas used) and fairly rapid (≤6 days after hatch for 72% of the females). Gosling survival was not related to distance moved between nesting and brood-rearing areas. However, gosling growth was influenced by areas used and whether or not they had to move to reach their brood-rearing area. Geese nesting at the main brood-rearing area generally reared heavier and larger goslings than those that moved ≈30 km from the main nesting colony to rear their brood at the main brood-rearing area. On the other hand, goslings leaving the nesting colony after hatch were heavier and larger than those that stayed there throughout brood rearing in one of two years. Although brood movements allow goslings access to high-quality habitats, they entail some costs. Thus, minimizing such movements through nest-site selection should provide a selective advantage by allowing goslings to maximize their growth.Croissance et Survie des Oisons en Relation avec les Déplacements des Familles chez Chen caerulescens atlantica
Sex-Related Natal Dispersal of White Storks (Ciconia Ciconia) in Poland: How Far and Where to?
Authors: Chernetsov Nikita , Chromik Wiesław , Dolata Pawel T. , Profus Piotr , Tryjanowski Piotr 
Published: September 2019

AbstractDistance and direction of natal dispersal were studied in a Polish White Stork (Ciconia ciconia) population on the basis of 25 years of banding and resighting data. Multiple regression analysis showed a significant sex-linked bias (females settled farther from the natal sites than males) and effect of banding year, in that dispersal distances were decreasing toward the end of the study period. Population indices in the hatching year and the presumed recruitment year did not help to explain the variance. The birds showed a trend toward settling southeast of the natal site, but this was significant only in individuals that settled within 50 km of the natal site. We suggest that when returning from winter sites in the southeast, young White Storks settle before they reach their presumed migratory target in the vicinity of the natal site. This is only possible if, in spite of a relatively high population density, many breeding areas and potential nesting sites remain vacant. This might also explain our failure to find density dependence in the interannual variation of dispersal distances.
Associations of Breeding Birds With Fire-Influenced and Riparian-Upland Gradients in a Longleaf Pine Ecosystem
Authors: Allen Jennifer C. , Krieger Sharlene M. , Walters Jeffrey R. , Collazo Jaime A. 
Published: September 2019

AbstractWe determined the effects of fire history and a riparian-upland gradient on the breeding bird community at Fort Bragg Military Installation in North Carolina, one of the largest remnant areas of the endangered longleaf pine (Pinus palustris) ecosystem. Study sites were classified into two treatments: fire-intense (areas experiencing growing-season burns) and fire-suppressed (areas lacking fires). Within each treatment, bird and vegetation data were recorded at point-count stations positioned at three distances from streamhead pocosins to characterize the riparian-upland habitat gradient: 0, 75, and ≥150 m. Total bird abundance and species richness varied significantly along the riparian-upland gradient, with pocosins contributing greatly to avian biodiversity. Our data revealed strong effects of fire history and riparian-upland gradient on bird species, which we described in terms of breeding-bird assemblages. Members of the open longleaf assemblage (e.g., Red- cockaded Woodpecker [Picoides borealis], Bachman's Sparrow [Aimophila aestivalis]) were most common in fire-intense areas and at upland locations. Members of the fire-suppressed assemblage (e.g., Wood Thrush [Hylocichla mustelina], Ovenbird [Seiurus aurocapilla]) were confined to pocosins in fire-intense areas, but became more abundant in fire-suppressed areas. Members of the pocosin assemblage (e.g., Eastern Towhee [Pipilo erythropthalamus], Common Yellowthroat [Geothlypis trichas]) were largely confined to pocosins and, in some cases, were most abundant in fire-intense pocosins. Fire suppression increased structural diversity of vegetation and promoted one breeding-bird assemblage (fire-suppressed), but at the expense of two others (open longleaf, pocosin). Continued management of Fort Bragg to promote longleaf pine restoration is essential for supporting conservation of the open-longleaf bird assemblage; in addition, it will benefit the pocosin assemblage.Asociaciones de Aves Reproductivas con Áreas Influenciadas por el Fuego y con Gradientes Ribereños-Tierras Altas en un Ecosistema de Pinus palustris
Carotenoids, Immunity, and Integumentary Coloration in Red Junglefowl (Gallus Gallus)
Authors: McGraw Kevin J. , Klasing Kirk C. 
Published: September 2019

Abstract
There is widespread interest in the roles that carotenoids play as yolk and shank pigments, antioxidants, and immune-system regulators in chickens, but nothing is known of such functions in the wild ancestors of chickens—the Red Junglefowl (Gallus gallus). We manipulated carotenoid access in the diet of captive male and female Red Junglefowl to investigate its effects on the coloration of the red comb and buff-brown legs and beak as well as on several indices of immunocompetence. Comb, leg, and beak did not differ in coloration between control and carotenoid-supplemented groups; in fact, biochemical analyses showed that, unlike in chickens, leg and beak tissue contained no carotenoids. Carotenoids showed variable effects on immunological performance, boosting the potency of whole blood in males to kill bacterial colonies, while inhibiting the ability of macrophages to phagocytize bacterial cells and having no significant effect on the accumulation of haptoglobin—an acute-phase protein whose production was induced by a simulated infectious challenge with lipopolysaccharide. These results bring into question interpretations of the evolutionary significance of carotenoid-based and sexually dichromatic shank coloration in domestic chickens, which was apparently derived through artificial selection, and suggest that carotenoids can exert different, mechanism-specific actions on the many lines of immune defense in birds.
Carotenoides, Inmunidad y Coloración Integumentaria en Gallus gallus
Estimating Detection Probabilities From Multiple-Observer Point Counts
Authors: Alldredge Mathew W. , Pollock Kenneth H. , Simons Theodore R. 
Published: September 2019

AbstractPoint counts are commonly used to obtain indices of bird population abundance. We present an independent-observer point-count method, a generalization of the dependent-observer approach, based on closed-population capture- recapture methods. The approach can incorporate individual covariates, such as detection distance, to account for individual differences in detection probabilities associated with measurable sources of variation. We demonstrate a negative bias in two-observer estimates by comparing abundance estimates from two- and four- observer point counts. Models incorporating data from four independent observers were capable of accounting for this bias. Modeling individual bird differences in detection probabilities produced abundance estimates 15–21% higher than models that did not account for individual differences, in four out of five data sets analyzed. Although independent-observer methods are expensive and impractical for large- scale applications, we believe they can provide important insights into the sources and degree of perception bias (i.e., probability of detecting an individual, given that it is available for detection) in avian point-count estimates. Therefore, they may be useful in a two-stage sampling framework to calibrate larger surveys based on single-observer estimates.Estimación de Probabilidades de Detección a Partir de Conteos en Puntos Hechos por Varios Observadores
Nesting Birds of a Tropical Frontier: The Lower Rio Grande Valley of Texas
Authors: Woodin Marc C. 
Published: September 2019

Abstract
The following critiques express the opinions of the individual evaluators regarding the strengths, weaknesses, and value of the books they review. As such, the appraisals are subjective assessments and do not necessarily reflect the opinions of the editors or any official policy of the American Ornithologists' Union.
Importance of Facial Pattern to Sexual Selection in Golden-Winged Warbler (Vermivora Chrysoptera)
Authors: Leichty Ellen R. , Grier James W. 
Published: September 2019

Abstract
The importance of the black facial pattern in sexual selection in Golden-winged Warblers (Vermivora chrysoptera) was evaluated through experimental plumage modification. We lightened the throat patch and eye mask with hair bleach, which essentially created artificial Brewster's Warbler (F1 generation of Golden-winged Warbler × Blue-winged Warbler [V. pinus]) plumage phenotypes. Experimental males lost their original territories and failed to obtain mates. We concluded that there is sexual selection against the Brewster's facial pattern. Sexual selection attributable to the face pattern may explain the apparent greater effect of hybridization on Golden-winged Warblers than on Blue-winged Warblers.
Importancia del Patrón Facial en la Selección Sexual de Vermivora chrysoptera
Courtship Ethology of Carola's Parotia (Parotia Carolae)
Authors: Scholes Edwin 
Published: September 2019

AbstractDetailed descriptions of behavior patterns are a major objective of ethology, because they serve as the basis for identifying the elements that constitute the behavioral component of the phenotype. In regard to avian courtship displays, the lack of detailed studies has limited the scope of modern ethological investigations. Recent advances in video technology have greatly improved the ability to analyze complex avian behaviors. I examined the ethology of courtship and mating in Carola's Parotia (Parotia carolae) using a modern approach intended to facilitate incorporation into existing bioinformatics databases. The questions addressed are as follows. (1) What are the courtship and mating behaviors of wild Carola's Parotias? (2) How are these behaviors structured? And (3) what are the units that constitute complex patterns of behavior? I used digital video to thoroughly characterize two wild populations of Carola's Parotias in Papua New Guinea. The results present a detailed picture of the species' complex courtship ethology, including description of 20 behaviors and the lower-level structure (or “anatomy”) of male displays, which alone comprise 58 distinct elements. The modular nature of displays is demonstrated through instances in which various units and subunits are used recurrently, differentially employed, and added or deleted.Etología del Cortejo en Parotia carolae
Singing Complexity of The Banded Wren (Thryothorus Pleurostictus): Do Switching Rate and Song-Type Diversity Send Different Messages?
Authors: Molles Laura E. 
Published: September 2019

AbstractMost species of songbird possess repertoires of song types or variations that allow singers to vary how they present their songs. “Complexity,” or the amount of variation in a singing performance, has several distinct components that include the number of song types used, variation within song types, and rate of switching between song types. Because singers can control each factor somewhat independently, different components may encode different kinds of information. In a series of interactive playbacks, I presented Banded Wrens (Thryothorus pleurostictus) with stimuli that altered song-type diversity and switching rates independently. My results show that switching rates affect males' aggressive approach responses, with lower switching rates eliciting stronger responses. By contrast, song-type diversity does not appear to affect males' approach responses when switching rates are held at a high and constant level. Although focal male switching rates and song-type diversity are not strongly influenced by playback type, males frequently respond to high-diversity playback with delayed matches. Delayed matching entails using one or more of the same song types from the playback, without immediate song- type matching. Although delayed matches occurred at levels above chance during high-diversity playbacks, focal males appeared to avoid them during other types of playback; immediate matches were rare and repertoire matches frequent for all playback treatments. Overall, males' responses to the three playback stimuli suggest that switching rate and song-type diversity encode different messages.Complejidad del Canto de Thryothorus pleurostictus: ¿Envían Diferentes Mensajes las Tasas de Cambio y la Diversidad de Tipos de Canto?
Stopover Habitat Along the Shoreline of Northern Lake Huron, Michigan: Emergent Aquatic Insects as a Food Resource for Spring Migrating Landbirds
Authors: Smith Robert J. , Moore Frank R. , May Christopher A. 
Published: September 2019

AbstractRecent work in Michigan's eastern Upper Peninsula suggests that terrestrial areas bordering northern Lake Huron provide important stopover habitat for spring migrating landbirds, principally because of the presence of emergent aquatic midges (Diptera: Chironomidae). Migrants were concentrated in lakeshore habitats abundant with midges during spring migration. American Redstarts (Setophaga ruticilla) and Black-throated Green Warblers (Dendroica virens) foraged and used habitat differently, depending on their distance from the lakeshore. Here, we describe results of an integrative study in which we sampled resources, quantified American Redstart foraging behavior, and estimated mass change in American Redstarts and five other common migrant landbird species to evaluate the importance of adult midges as an early season resource for spring migrants. Resource sampling and American Redstart foraging behavior suggested that more food was available in shoreline habitats than inland during spring migration. Furthermore, migrants gained mass in shoreline habitat during stopover, which supports the argument that nearshore areas provide important stopover habitat for spring migrants. Finally, resource sampling, mass change estimates, and American Redstart foraging behavior suggested that midges and spiders (Araneae: Arachnidae) provided an important early season resource for migrating landbirds. Evidence suggests that midges were responsible for elevated spider abundance at the shoreline and that birds foraged on both midges and spiders. Midges appear to play an important role in providing high-quality stopover habitat for landbirds migrating through Michigan's eastern Upper Peninsula.Hábitat de las Paradas Migratorias a lo Largo de la Costa Norte del Lago Huron, Michigan: Insectos Acuáticos Emergentes como Recurso Alimenticio para las Aves Terrestres Migratorias Durante la Primavera
Species Limits in Antbirds (Thamnophilidae): The Warbling Antbird (Hypocnemis Cantator) Complex
Authors: Isler Morton L. , Isler Phyllis R. , Whitney Bret M. 
Published: September 2019

Abstract
Six populations of Warbling Antbird (Hypocnemis cantator) currently considered subspecies are more appropriately recognized as species, given the multiplicity of vocal differences that distinguishes them. These vocal differences are as great or greater than vocal differences documented between syntopic species-pairs in the family Thamnophilidae (Isler et al. 1998). Evidence is also provided that two forms currently considered subspecies are syntopic and that two others are parapatric without apparent physical barriers. Vocally, the pair of syntopic taxa were distinguished dramatically, but solely, by common calls. The finding that common calls were as diversified as songs in this species-group suggests that calls may be as important as songs in reproductive isolation. Future field studies should therefore focus on clarifying the function of different types of thamnophilid vocalizations and elucidating their role in speciation. This is the first contribution to a multifaceted analysis of the vocalizations and genetic structure of typical antbirds (Thamnophilidae) in Amazonia. In future work, results of the vocal analysis will be compared with a parallel genetic study, after which the two analyses will be integrated to suggest a phylogeny. The present study and preliminary studies of genetic differentiation (e.g., Bates et al. 1999) make it clear that the H. cantator complex has had a long evolutionary history that produced greater species-level diversity than was recognized previously.
Límites de Especies en Thamnophilidae: El Complejo de Hypocnemis cantator
Daily Mass Changes in Landbirds During Migration Stopover on the South Shore of Lake Ontario
Authors: Bonter David N. , Donovan Therese M. , Brooks Elizabeth W. 
Published: September 2019

AbstractAssigning conservation priorities to areas used by birds during migration requires information on the relative quality of areas and habitats. The rate at which migratory birds replenish energy reserves during stopover may be used as an indicator of stopover-site quality. We estimated the rate of mass gain of 34 landbird species during stopover at a near-shore terrestrial site on the south shore of Lake Ontario in New York during 12 migration seasons from 1999 to 2004. The average rate of mass gain was estimated by relating a measure of condition to time of capture (hour after sunrise) with linear regression. Data from 25,385 captures were analyzed. Significantly positive rates of mass change were detected for 20 of 30 species during spring migration and 19 of 21 species during autumn migration. No significantly negative trends were detected in either season. Daily rates of mass gain across all species averaged 9.84% of average lean body weight during spring migration and 9.77% during autumn migration. Our regression estimates were significantly greater than estimates from traditional analyses that examine mass changes in recaptured birds. Analyses of mass changes in recaptured birds revealed a mean daily change of −0.68% of average lean mass in spring and 0.13% in autumn. Because of sampling biases inherent in recapture analyses, the regression approach is likely more accurate when the assumptions of the method are met. Similar studies in various habitats, landscapes, and regions are required to prioritize conservation efforts targeting migratory stages of the annual cycle.Cambios de Peso Diarios de Aves Terrestres durante las Paradas Migratorias en la Costa sur del Lago Ontario
Avian Visual Perspective on Plumage Coloration Confirms Rarity of Sexually Monochromatic North American Passerines
Authors: Eaton Muir D. 
Published: September 2019

AbstractMale and female birds can exhibit striking differences in morphology (dimorphism), including exaggerated plumage structures, size differences, and feather color differences, yet most species are considered to have identical sexes. Classification of a species as sexually monochromatic (identical coloration between the sexes) has traditionally been based on human visual perception. Research over the past two decades has shown that birds see each other and the world differently than their human investigators; these visual differences, combined with objective color measurements, suggest that traditional assessments of plumage coloration may be questionable from an avian visual perspective (Cuthill et al. 1999). I tested the avian reality of human categorization of sexually monochromatic plumages for North American passerines. I found, on the basis of plumage-reflectance data and modeled avian color-discrimination thresholds, that 91.6% of the presumed sexually monochromatic species I sampled are sexually dichromatic to birds, which confirms the rarity of sexually monochromatic bird species. This study informs future work as to potential sources of plumage signals hidden from human observers and generates testable predictions regarding avian sex-recognition via plumage signals.La Coloración del Plumaje desde la Perspectiva de la Visión de las Aves Confirma la Rareza del Monocromatismo Sexual en las Aves Paserinas de Norte América
Brood Sex Ratios are Related to Male Size but not to Attractiveness in Common Yellowthroats (Geothlypis Trichas)
Authors: Abroe Betsy , Garvin Julia C. , Pedersen Marc C. , Whittingham Linda A. , Dunn Peter O. 
Published: September 2019

AbstractWhen the reproductive value of sons differs from that of daughters, selection will favor broods biased toward the sex that can provide greater fitness benefits. In species where female choice is based on male ornamentation, females mated to highly ornamented males may experience a reproductive advantage by skewing the brood sex ratio toward sons. In the Common Yellowthroat (Geothlypis trichas), males with larger black facial masks are more likely to gain a social mate and sire extrapair young and, as a result, have increased seasonal reproductive success. Females mated to larger-masked males could benefit if they produced more sons. Given that larger- masked males are preferred as extrapair sires, females may also benefit by producing more extrapair sons. We tested these hypotheses during a five-year study of Common Yellowthroats in Wisconsin. Contrary to our predictions, females did not produce more sons when mated to males with larger masks, and extrapair young were not more likely to be male. However, sons were more likely to be sired by males with longer tarsi, which suggests that females may respond to male body size rather than to male ornament size.El Cociente de Sexos en las Nidadas Está Relacionado con el Tamaño de los Machos pero no con el Atractivo en Geothlypis trichas