bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adult Survival Estimates From Two Atlantic Puffin (Fratercula Arctica) Colonies in The Gulf of Maine
Authors: Breton André R. , Diamond Antony W. , Kress Stephen W. 
Published: September 2019

AbstractWe report survival probabilities for 148 breeding adult Atlantic Puffins (Fratercula arctica) monitored through capture-mark-resight at two colonies for 11 years (1992–2003). The colonies, Eastern Egg Rock and Seal Island, are ∼42 km apart in the Gulf of Maine. Support for competing models in the program MARK suggests constant survival of 0.95 ± 0.01 (SE) that is independent of colony. Our high survival probability is consistent with published estimates for Atlantic Puffins and other long-lived seabirds. No time-variance contrasts with many long-term seabird studies, which often report high survival in most years, broken occasionally by low-survival events. However, a post-hoc observation of survival estimates from the time-dependent model suggests that there may have been at least two low-survival events in our time-series; sparse data may have precluded detection by our models. In this study, each bird received an individually engraved, plastic, field-readable leg band, as well as the standard metal band. Using an index of band readability, we show that plastic bands wore rapidly, resulting in accumulating losses of engraved characters through time. Degradation and loss of marks is a common source of overdispersion in capture-mark-re-encounter data and results in underestimated sampling variances. In the presence of a 70% reduction in band readability over eight years, an estimate of the adjusted overdispersion factor (ĉ = 1.14) identified very little overdispersion in our data. Overdispersion was avoided by double banding and intensively resighting metal bands.Estimation de la Survie Adulte de Deux Colonies de Fratercula arctica dans le Golfe du Maine
Quantifying Differential Responses to Fruit Abundance by Two Rainforest Birds Using Long-Term Isotopic Monitoring
Authors: Herrera M. L. Gerardo , Hobson Keith A. , Hernández C. Patricia , Rodríguez G. Malinalli 
Published: September 2019

AbstractMost tropical passerines feed on insects, fruit, or a combination of the two. The sugary pulps of fruit have lower amounts of protein than insects. We used stable-nitrogen isotope analysis (δ15N) of blood from two tropical rainforest birds that regularly feed on fruit—Red-throated Ant-Tanager (Habia fuscicauda) and Ochre-bellied Flycatcher (Mionectes oleagineus)—to quantify the relative amounts of assimilated protein from animal and plant sources. Because fruit and insect abundances vary seasonally in the tropics, the study was conducted during one year in Los Tuxtlas, Mexico. The study site has one major fruiting peak between April and July and a secondary peak between September and October. Some insects are more abundant from May to August. Red-throated Ant-Tanagers and Ochre-bellied Flycatchers rely heavily on insect protein when fruit is scarce, and then steadily increase their input of fruit protein as fruit abundance increases. Red-throated Ant-Tanagers rely almost entirely on fruit protein during the major fruiting peak, whereas Ochre-bellied Flycatchers have the largest input of fruit protein during the secondary fruit peak. Incubation in both species occurs from June to August, and most incubating individuals rely on a mixture of insects and fruit. In both species, examination of fecal contents showed the ingestion of the largest number of fruit species during the major fruiting peak.Cuantificación de la Respuesta Diferencial a la Abundancia de Frutos por Dos Especies de Aves Selváticas Mediante el Monitoreo Isotópico a Largo Plazo
Large-Scale Movement Patterns Between Song Dialects in Brown-Headed Cowbirds (Molothrus Ater)
Authors: Anderson Kurt E. , Rothstein Stephen I. , Fleischer Robert C. , O’Loghlen Adrian L. 
Published: September 2019

AbstractExtensive past research has attempted to determine whether song dialects represent reproductively isolated social systems, with individuals tending to spend their entire lives in a single dialect. We addressed that issue by analyzing banding data for Brown-headed Cowbirds (Molothrus ater) on the eastern slope of the Sierra Nevada of California. For 14 years, 1,393 juveniles and 2,568 mature individuals were banded along a 40-km span encompassing three dialects. Of those juvenile and mature birds, 7.9% and 12.1%, respectively, were recaptured in a later year. All classes of mature birds (second-year males, older males, and females) had significantly higher recapture rates than birds banded as juveniles, but there were no differences among the mature classes. Overall, 22.7% of 110 juveniles recaptured in a subsequent year were trapped in a dialect region other than the one in which they were banded, as compared with 8.1% of 310 mature birds. Neither juvenile nor mature birds showed sex-related differences in proportions recaptured in subsequent years in different dialect regions. Birds in all sex-age classes were more likely to have moved to a new dialect region when recaptured in a subsequent year than when recaptured within the year, which suggests that apparent movements between years were cases of dispersal, rather than short-term foraging trips. Although our banding data cannot confirm gene flow, the high levels of movement they show agree with genetic and morphometric studies indicating high levels of gene flow among these cowbird dialects.Patrones de Movimiento de Gran Escala entre Dialectos del Canto de Molothrus ater
Cultural Divergence Within Novel Song in The Black-Capped Chickadee (Poecile Atricapillus)
Authors: Gammon David E. , Baker Myron C. , Tipton John R. 
Published: September 2019

AbstractGeographic variation in learned vocalizations is commonly attributed, in part, to imperfect song learning, but rarely has this been documented. Additionally, we know little about how spatial structure of populations affects geographic divergence in song. Using novel fee-bee song in Black-capped Chickadees (Poecile atricapillus) in Fort Collins, Colorado, we investigated both of those concepts by recording songs from juveniles at the time of natal dispersal and from adults at study sites along a continuous riparian corridor and in small isolated populations north of Fort Collins. Acoustic differences within juveniles' songs corresponded to acoustic differences distinguishing the songs of adults from separate study sites. We also found more acoustic divergence among the small isolated populations than among the continuously distributed riparian populations, and we found that the song-type grouping most similar in acoustic structure to the stereotyped continental fee-bee diverged the least. These findings suggest that song variants introduced by developing juveniles can indeed account for geographic variation and that song diverges more in small isolated populations.Divergencia Cultural en los Cantos Aprendidos en Poecile atricapillus
Wing Morphology and Flight Behavior of Some North American Hummingbird Species
Authors: Stiles F. Gary , Altshuler Douglas L. , Dudley Robert 
Published: September 2019

AbstractWe explored the relationship between wing morphology and flight behavior with respect to sex and age in five species of North American hummingbirds. We first measured the length, chord or “width,“ and area of entire hummingbird wing planforms. We then calculated additional parameters of wing shape and size, including aspect and shape ratios, degree of taper or “pointedness,“ wing loading, and wing disc loading (WDL). Wings of adult males are not only shorter but also more narrow and tapered than those of adult or immature females; immature males have larger wings and lower WDL, more like those of females. A proposed relationship between WDL and territorial behavior and dominance is not supported, given that adult and immature males show similar feeding territoriality outside the breeding season but females rarely do. The more extreme and divergent wings of adult males probably reflect sexual selection in connection with aerial displays that include species-specific sound effects given during the breeding season. North American species are unusual among hummingbirds in showing reversed sexual size-dimorphism (males smaller, with relatively shorter wings), a feature shared with some other small hummingbirds, notably the “Pygmornis“ hermits. Attempts to explain hummingbird foraging and territorial behavior on the basis of differences in WDL have failed because many aspects of wing morphology, physiology, and flight behavior were not taken into account. Several wing parameters appear more related to other modes of flight than to strategies of nectar exploitation, and the morphology of any given wing represents a compromise between the often conflicting aerodynamic demands of different flight modes. Understanding hummingbird flight will require broad comparative studies of wing morphology and wingbeat kinematics in relation to flight behavior, and new theoretical models and experimental data will be needed to elucidate physiological and aerodynamic mechanisms underlying forward flight and maneuvering.Morfología Alar y Comportamiento de Vuelo de Unas Especies de Colibríes de Norteamérica
Overlap in Diets and Foraging of Common Murres (Uria Aalge) and Rhinoceros Auklets (Cerorhinca Monocerata) After the Breeding Season
Authors: Lance Monique M. , Thompson Christopher W. 
Published: September 2019

AbstractCommon Murres (Uria aalge; hereafter “murres“) and Rhinoceros Auklets (Cerorhinca monocerata; hereafter “auklets“) breed and forage sympatrically over much of their range. They have similar diets during the breeding season, which suggests that they partition prey during the breeding season by foraging (1) at different locations, (2) at different times of day, (3) at different water depths, (4) on different proportions of the same prey species, or (5) some combination of the four. We examined possible mechanisms of niche partitioning during late summer and fall in Puget Sound, Washington, in 1993-1996. Murres and auklets fed mainly on Pacific herring (Clupea pallasii, occurring in 74.2% and 48.1%, respectively, of gastrointestinal tracts with contents), Pacific sand lance (Ammodytes hexapterus; 45.8% and 62.3%), and salmonid (Oncorhynchus spp.) species (21.9% and 9.7%). Auklets also consumed considerable amounts of threespine stickleback (Gasterosteus aculeatus; 26.6%). Murres and auklets did not differ significantly (1) in their diet (between age classes or sexes of either species, or among years); (2) in mean lengths of Pacific herring (101 and 109 mm, respectively) and Pacific sand lance (82 and 86 mm) they consumed; or (3) in the mean depth (7–8 m) at which they were entangled in gill nets. Dietary diversity was low, with most gastrointestinal tracts containing only one or two prey species in both murres and auklets. Murres were caught and therefore presumably feed more frequently in the afternoon and evening; whereas auklets were entangled more often in early morning. We found differences between murres and auklets in the diel chronology of prey taken, which may partly explain how murres and auklets coexist during the breeding season and months thereafter, prior to auklet emigration from Puget Sound.Chevauchement du Régime Alimentaire et de la Quête Alimentaire chez Uria aalge et Cerorhinca monocerata après la Saison de Reproduction
Temporal and Geographic Patterns of Age-Specific Gull Plumage in Relation to Potential Exposure to Polychlorinated Biphenyls
Authors: Sampieri Sara J. , Clotfelter Ethan D. 
Published: September 2019

AbstractStudy skins of Herring Gulls (Larus argentatus) and Great Black-backed Gulls (L. marinus) collected over a period of ∼150 years in the northeastern United States were used to test the hypothesis that potential exposure to polychlorinated biphenyls (PCBs) has an effect on age-related plumage coloration. We found no changes in the average age class (as determined by plumage) of gulls collected before and after 1930 (date PCBs began to be used) and no differences in average age class in birds collected near PCB-contaminated sites versus those collected far from such sites. We found significant skews in the age distributions of birds in our sample because of an under-representation of birds of intermediate age classes, but those skews were similar in pre- and post-1930 data sets and thus likely represent sampling errors and not the effects of PCBs. There was no difference in the age distribution of gulls collected near or far from contaminated sites. Our study, albeit indirectly, shows no evidence that PCB exposure affects plumage maturation rate in piscivorous gulls.Patrons Géographiques et Temporels du Plumage chez les Laridés en Fonction de l’\bcp\A\ecp\ge et de l’Exposition Potentielle aux Polychlorobiphényles
Body Composition and Flight Ranges of Bar-Tailed Godwits (Limosa Lapponica Baueri) From New Zealand
Authors: Battley Phil F. , Piersma Theunis 
Published: September 2019

AbstractBody composition analysis was performed on 37 Bar-tailed Godwits (Limosa lapponica baueri) that had been illegally shot during migratory fueling in northern New Zealand in March 1992. Adults (n = 35) were heavy (442–721 g), with fat loads of 30–45% of body mass. Two first-year males had only 5.4% and 8.9% fat, respectively, and had 13% less lean (fat-free dry) tissue than the average adult male. Males and females scaled along the same size axes, with little overlap between the sexes (females were larger). Larger birds carried more fat, but fat loads did not differ systematically with size (and, therefore, sex). Fatter birds (after accounting for body size) had larger flight muscle and lung masses, implying premigratory hypertrophy. Males that were not in body molt were fatter, but less colorful, than molting birds. They were also longer-winged and had larger testes but smaller intestines and salt glands, which suggests that they may belong to a subpopulation with a different fueling and molt strategy. Comparison between L. l. baueri and a smaller subspecies (L. l. taymyrensis) indicated that although the two subspecies scaled along the same lean mass-size axes, L. l. baueri deposited much more fat for their body size (1.7 × more than the equivalent-sized L. l. taymyrensis). On the basis of estimated travel costs for L. l. taymyrensis, predicted flight ranges for L. l. baueri ranged from 6,000 to 8,600 km, depending on whether wind assistance is assumed. That suggests that direct flights from New Zealand to southeastern or eastern Asia are possible (e.g. Philippines, 7,200 km; Japan, 8,700; South Korea, 9,100 km).Composition Corporelle et Distance de Vol chez Limosa lapponica baueri de Nouvelle-Zélande
Evidence of Latitudinal Sexual Segregation Among Migratory Birds Wintering in Mexico
Authors: Komar Oliver , O’Shea B. J. , Peterson A. Townsend , Navarro-Sigüenza Adolfo G. 
Published: September 2019

AbstractLatitudinal sexual segregation during the nonbreeding season, in which males tend to winter farther north than females, is known to occur in many temperate-zone bird species. This pattern, however, has rarely been reported in species wintering in tropical regions. We investigated latitudinal sexual segregation in 45 Nearctic-Neotropical migratory bird species that winter in Mexico, using specimen records from 35 natural-history museums. We found significant latitudinal segregation in nine species: Yellow-bellied Sapsucker (Sphyrapicus varius), Swainson’s Thrush (Catharus ustulatus), Orange-crowned Warbler (Vermivora celata), Yellow Warbler (Dendroica petechia; aestiva group), Yellow-rumped Warbler (Dendroica coronata; coronata group), Black-and-white Warbler (Mniotilta varia), Ovenbird (Seiurus aurocapilla), Wilson’s Warbler (Wilsonia pusilla), and Indigo Bunting (Passerina cyanea). In most cases, males predominated in the northern part of species’ winter ranges and females in the south, but the trend was reversed in Indigo Buntings. Discovering the frequency of latitudinal sexual segregation in Neotropical migratory birds will influence understanding of avian ecology and migration systems.Evidencia de la Segregación Latitudinal Sexual en Aves Migratorias durante el Invierno en México
Phylogeography of The Mallard (Anas Platyrhynchos): Hybridization, Dispersal, and Lineage Sorting Contribute to Complex Geographic Structure
Authors: Kulikova Irina V. , Drovetski Sergei V. , Gibson Daniel D. , Harrigan Ryan J. , Rohwer Sievert , Sorenson Michael D. , Winker Kevin , Zhuravlev Yuri N. , McCracken Kevin G. 
Published: September 2019

AbstractPopulation genetic variation in Mallards (Anas platyrhynchos; n = 152) from Western Russia, North Asia, the Aleutian Islands, and mainland Alaska was investigated using 667 base pairs of the 5′-end of the mitochondrial DNA (mtDNA) control region. DNA sequencing revealed two clades that correspond to Avise et al.’s (1990) group A and B mtDNA haplotypes. Group A haplotypes (80.3%) were wide- spread in all localities from Western Russia to Alaska. Group B haplotypes (19.7%), by contrast, were found primarily in mainland Alaska, where they occurred at high frequency (77.4%), but they also occurred at low frequencies (declining east to west) in the Aleutian Islands (11.8%) and the Primorye region of North Asia (4.4%). Group B haplotypes were not observed in Western Russia or elsewhere in North Asia outside Primorye. Consequently, Mallards exhibited substantial genetic structure between Old World and New World (ΦST = 0.4112–0.4956) but possessed little genetic structure within the Old World continental area (ΦST = 0.0018). Nonetheless, when only group A haplotypes were included in the analysis, Mallards from the Aleutian Islands differed (albeit with low levels of divergence) from each of the other three sampled regions in the Old World and New World (ΦST = 0.0728–0.1461, P < 0.05). Mallards inhabit the Aleutian Islands year-round, so these insular populations may be isolated from Asian and North American populations that occur in the Aleutian Islands only during migration. Overall weak phylogeographic structure and low genetic differentiation within Asia, and between Asia and North America when only group A haplotypes were evaluated, is probably explained by large long-term population sizes and significant intra-continental dispersal. The coexistence and nonrandom distribution of two divergent mtDNA haplotype lineages in Alaska, the Aleutian Islands, and the Primorye region of North Asia, but not in Western Russia or elsewhere in North Asia, is consistent with historical and contemporary hybridization and incomplete sorting of A and B mtDNA haplotype lineages in Mallards and closely related species inhabiting the Old World and New World.
A New Species of Scimitar-Babbler (Timaliidae: Jabouilleia) From the Sub-Himalayan Region of Myanmar
Authors: Rappole John H. , Renner Swen C. , Shwe Nay Myo , Sweet Paul R. 
Published: September 2019

AbstractAn expedition of representatives from the Myanmar Nature and Wildlife Conservation Division and the Smithsonian National Zoological Park's Conservation and Research Center visited the town of Naung Mung on the Nam Tisang River in the extreme northern portion of Kachin State, Myanmar, during February 2004. The town is located in the sub-Himalayan region of the country at 27°29′N, 97°48′E, elevation 540 m, 118 km south of the Tibetan border and 53 km west of the border with Yunnan Province, China. The purpose of the trip was to inventory the poorly known avifauna of the premontane temperate rainforest habitat at that site. On 6 February 2004, we captured two scimitar-babblers that appeared to be representatives of the genus Jabouilleia. An additional individual of the taxon was captured in the same vicinity on 8 February 2004. These were the first records for Jabouilleia from Myanmar, and subsequent investigation showed that these specimens were members of a previously undescribed species, which we designate Jabouilleia naungmungensis, the Naung Mung Scimitar-Babbler.Une Nouvelle Espèce de Jabouilleia (Timaliidae) dans la Région sub-Himalayenne de la Birmanie
Molt Strategies and Age Differences in Migration Timing Among Autumn Landbird Migrants in Southwestern Idaho
Authors: Carlisle Jay D. , Kaltenecker Gregory S. , Swanson David L. 
Published: September 2019

AbstractIntraspecific patterns of autumn migration timing are not well known, particularly in the western United States. Here, we (1) describe autumn migration timing and age ratios of landbird migrants in southwestern Idaho, (2) examine differences in timing among age and sex classes, and (3) demonstrate how prebasic molt strategies affect migration timing differences between age classes. As a group, Neotropical migrants were most common from late July through early September, whereas temperate migrants were most common from mid-September into early October. Proportion of hatch-year birds was 74.5% for all migrants combined and ranged from 33.3% to 100% for individual species. Timing differences between sex classes were detected in only a few species and no general patterns emerged. In 22 of 31 Neotropical and temperate migrants examined, there were significant differences in timing between adults and hatch-year birds. In species in which adults begin fall migration before replacing flight feathers, adults migrated earlier than hatch-year birds. Conversely, in species in which adults molt flight feathers on or near the breeding grounds before departing on fall migration, hatch-year birds migrated earlier than adults in all but one case. Therefore, it appears that molt strategy is a powerful determinant of intraspecific migration timing differences and, to our knowledge, this is the first study to document this pattern among migrant passerines of North America.Estrategias de Muda y Diferencias en el Momento de Migración Otoñal en Migrantes Terrestres en el Suroeste de Idaho
Resource Availability Controls Bird-Assemblage Composition Through Interspecific Aggression
Authors: Mac Nally Ralph , Timewell Christopher A. R. 
Published: September 2019

AbstractHigh-value resources are often defended aggressively by consumers, which can alter assemblage structure and dynamics. Here, we describe a system of nectarivorous bird assemblages exploiting pockets of eucalypt woodlands that differ dramatically in flowering and provision of nectar. The behavioral dominant, the Red Wattlebird (Anthochaera curunculata), aggressively reduces the occurrence and activities of other honeyeaters of the genera Lichenostomus and Melithreptus on sites of intense flowering. The latter genera predominate in moderately flowering areas, but few honeyeaters occupy poorly flowering sites. To understand such systems, in which temporal variation in habitat quality can be great, one needs to consider not only the disparity in habitat quality among locations but also the spatial extent of habitats of different quality. Isoleg analysis is a theoretical tool developed to understand how dominant and subordinate species partition habitats as a function of their respective densities. Our results suggest that isoleg analysis needs to be developed with spatial explicitness to capture variation in extent of habitats of different qualities and consequent effects on the usefulness of aggression for domination of resources.La Disponibilidad de Recursos Controla la Composición de los Ensambles de Aves a través de las Agresiones Interespecíficas