bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tufted Puffins (Fratercula Cirrhata) Respond to Predation Danger During Colony Approach Flights
Authors: Addison BriAnne , Ydenberg Ronald C. , Smith Barry D. 
Published: September 2019

AbstractIn spite of their putative importance in the evolution of certain traits (e.g., nocturnality, coloniality, cliff nesting), the effects of aerial predators on behavior of adult seabirds at colonies have been poorly investigated. We hypothesized that Tufted Puffins (Fratercula cirrhata) respond to danger posed by aerial predators by modifying their behavior to mitigate danger. We observed Tufted Puffins making repeated colony fly-ins and departures and characterized (1) the timing of this behavior, (2) the activity rate (number of birds arriving or departing), and (3) the risk-level of activity, with respect to predation danger posed by Bald Eagles (Haliaeetus leucocephalus) and Peregrine Falcons (Falco peregrinus). As we predicted, we found that Tufted Puffins (1) dilute danger by synchronizing their fly-in and departure activities, (2) reduce fly-in and departure activity rates when predators are present, and (3) switch to lower-risk fly-in activities (e.g., staying over water where they have an escape route from an aerial attack) when predators are present.Réaction de Fratercula cirrhata au Danger de Prédation au cours des Vols d'Approche de la Colonie
Incorporating Availability for Detection in Estimates of Bird Abundance
Authors: Diefenbach Duane R. , Marshall Matthew R. , Mattice Jennifer A. , Brauning Daniel W. 
Published: September 2019

AbstractSeveral bird-survey methods have been proposed that provide an estimated detection probability so that bird-count statistics can be used to estimate bird abundance. However, some of these estimators adjust counts of birds observed by the probability that a bird is detected and assume that all birds are available to be detected at the time of the survey. We marked male Henslow's Sparrows (Ammodramus henslowii) and Grasshopper Sparrows (A. savannarum) and monitored their behavior during May-July 2002 and 2003 to estimate the proportion of time they were available for detection. We found that the availability of Henslow's Sparrows declined in late June to <10% for 5- or 10-min point counts when a male had to sing and be visible to the observer; but during 20 May-19 June, males were available for detection 39.1% (SD = 27.3) of the time for 5-min point counts and 43.9% (SD = 28.9) of the time for 10-min point counts (n = 54). We detected no temporal changes in availability for Grasshopper Sparrows, but estimated availability to be much lower for 5-min point counts (10.3%, SD = 12.2) than for 10-min point counts (19.2%, SD = 22.3) when males had to be visible and sing during the sampling period (n = 80). For distance sampling, we estimated the availability of Henslow's Sparrows to be 44.2% (SD = 29.0) and the availability of Grasshopper Sparrows to be 20.6% (SD = 23.5). We show how our estimates of availability can be incorporated in the abundance and variance estimators for distance sampling and modify the abundance and variance estimators for the double-observer method. Methods that directly estimate availability from bird counts but also incorporate detection probabilities need further development and will be important for obtaining unbiased estimates of abundance for these species.Incorporación de la Disponibilidad para la Detección en las Estimaciones de Abundancia de Aves
Postfledging Survival and Movement in Dickcissels (Spiza Americana): Implications for Habitat Management and Conservation
Authors: Berkeley Lorelle I. , McCarty John P. , Wolfenbarger L. LaReesa 
Published: September 2019

Abstract
When land managers incorporate the habitat needs of grassland birds into their planning, they typically rely on management recommendations based on habitat use by adults during nesting. Habitat requirements for other critical life stages are seldom known and may differ from those of nesting adults. Using radio-telemetry, we examined survival and habitat use by juvenile Dickcissels (Spiza americana) during the postfledging period. In 2003 and 2004, we monitored 60 fledgling Dickcissels for ≤30 days after they left the nest. Mortality rates were highest during the first week after leaving the nest, and only 33% of the fledglings survived the first four weeks after leaving the nest. Estimated mean survival times were 16.9 ± 1.6 days after birds left the nest. In both years, fledgling survival was positively associated with dense vertical and horizontal structure of forbs at nests. Survival tended to be positively associated with vertical grass density on adult territories and negatively associated with patchily distributed forbs on adult territories. Fledgling habitat use was restricted to areas where Dickcissels nested and adjacent fields. Habitats used included corn and soybean fields, grasslands, and wetlands. Our results suggest that the fledgling period is a critical stage for Dickcissels and that fledglings require habitat similar to habitat used for nesting.
Supervivencia Durante el Período Posterior al Emplumamiento en Spiza americana: Implicancias para el Manejo de Hábitat y Conservación
Population Structure and Mitochondrial Polyphyly in North American Gadwalls (Anas Strepera)
Authors: Peters Jeffrey L. , Omland Kevin E. 
Published: September 2019

AbstractWe examined population genetic structure in Gadwalls (Anas strepera) to test the prediction that female philopatry and fidelity to migratory flyways have contributed to the partitioning of mitochondrial variation across North America. Sequencing a 658–659 base-pair fragment of the mitochondrial DNA (mtDNA) control region from 348 Gadwalls, we found two distinct clades that were broadly intermixed across both breeding and nonbreeding populations. Clade A was abundant in North America as well as among published sequences from Eurasia. Clade B was sequenced from 5.5% of North American Gadwalls and was more similar to Asian Falcated Duck (A. falcata) haplotypes than to clade A haplotypes. Maximum likelihood indicated that Gadwall clade B haplotypes were a monophyletic group nested within Falcated Duck haplotypes, which suggests mtDNA introgression of clade B into Gadwalls. However, that topology was weakly supported, and we could not reject topologies that were consistent with incomplete lineage-sorting as the cause of mitochondrial polyphyly. Migratory flyways did not contribute significantly to population structure and, in general, we found a lack of genetic structure among most populations. However, Gadwalls sampled in Alaska and Washington were well differentiated from other populations. Coalescent analyses supported a historical population expansion for clade A, and this expansion could have contributed to the high genetic similarity among some populations but the strong differentiation of others. Female-mediated gene flow, along with both historical and contemporary population and range expansions, has likely contributed to the overall weak mtDNA structure in North American Gadwalls.Estructura Poblacional y Polifilia Mitocondrial en Anas strepera
Patterns of Molecular and Morphological Variation in Some Solomon Island Land Birds
Authors: Smith Catherine E. , Filardi Christopher E. 
Published: September 2019

AbstractThe Solomon Archipelago is the largest and most biologically complex archipelago in northern Melanesia. We collected tissues and voucher specimens from codistributed bird species found on five island groups that provided the first opportunity to apply molecular methods to this avifauna. Using the mitochondrial marker ND2, we constructed a series of intraspecific phylogenies for 23 ecologically and taxonomically diverse species (13 families from 5 orders). Intraspecific comparisons across islands revealed a broad range of genetic differentiation, from 0% in widespread dispersive species such as Eurystomus orientalis and Nectarinia jugularis, to as high as 4–8% in species such as Ceyx lepidus and Dicaeum aeneum. Fifteen of the 23 species had well-supported phylogeographic structure, and for many of these, endemic and otherwise, molecular phylogenetic relationships closely matched those delineated by morphology. However, degrees of genetic differentiation appeared to be inconsistent across taxonomic designations, and the monophyly of some endemic taxa was not well supported. The data reveal the limits of morphology in tracking complex evolutionary histories and suggest that taxonomic revision of some Solomon Islands birds is warranted. As the first molecular analyses of this avifauna, results presented here create a platform for further biogeographic and evolutionary studies of bird diversity in this influential region.Patrons de variation moléculaire et morphologique chez quelques oiseaux terrestres des îles Salomon
A Cautionary Tale: Cryptic Sexual Size Dimorphism in a Socially Monogamous Passerine
Authors: Murphy Michael T. 
Published: September 2019

AbstractAmong socially monogamous birds, standard metrics suggest that males are only ∼5% larger than females. An untested assumption is that, with the exception of reproductive systems, males and females are scaled mirror images of one another. I used external morphological and skeletal data, and information on muscle mass and organ size, to test this assumption in a population of breeding Eastern Kingbirds (Tyrannus tyrannus). Male and female Eastern Kingbirds exhibited no differences in body mass or standard measures of size, except in a longer (∼6%) wing chord and tail in males. However, keel length, a character rarely measured in the field, was 9.7% larger in males. In principal component analysis, overall body size (PC1) failed to differ between the sexes unless keel length was included. Analysis of 16 skeletal characters also showed that only the bones associated with flight were larger in males. However, the most significant differences between the sexes was that lean dry pectoral muscle mass (LDPMM) was nearly 30% greater in males, whereas the alimentary tract was 27.5% heavier in females. Females also carried more fat. In both sexes, LDPMM scaled in a positive allometric manner with body mass (i.e., slope > 1.0), but the significantly higher slope of males suggested especially strong selection for large muscle mass and, presumably, greater power generation during flight. Eastern Kingbirds thus exhibit pronounced cryptic sexual size dimorphism, but it is not clear whether natural or sexual selection is responsible. These data call for a broader perspective for measuring and a re-evaluation of sexual size dimorphism in other socially monogamous species.Un Llamado de Atención: Dimorfismo Críptico en el Tamaño en un Paserino Socialmente Monógamo
Color Variation Among Nestling Brown-Headed Cowbirds (Molothrus Ater) Does Not Reflect Differential Success With Hosts in Texas
Authors: Ellison Kevin , Sealy Spencer G. , McGaha Hope R. 
Published: September 2019

AbstractAs brood parasites, nestling Brown-headed Cowbirds (Molothrus ater) may exhibit characters that improve their fledging success when reared alongside host young. The coloration of mouthparts of nestlings can influence adult care and, thus, the polymorphism of yellow or white rictal flanges among nestling Brown-headed Cowbirds may reflect differential success with different hosts on the basis of flange color. Moreover, because Brown-headed Cowbirds in the southern United States co-occur with Bronzed Cowbirds (M. aeneus), whose young have white flanges, cowbird nestlings' flange colors may reflect a means for reducing interspecific competition through partitioning of host species on the basis of nestling flange color. To determine whether flange color influences cowbird fledging success with hosts of either color, we recorded the flange colors of cowbirds and their hosts at a site in Texas. We also tested whether flange color was influenced by nestling sex. Most hosts of Brown-headed Cowbirds had young with yellow flanges (81%, n = 16 spp.), yet Brown-headed Cowbirds with white flanges were more common (61%, n = 107). Bronzed Cowbirds parasitized primarily species whose young had white flanges (86%, n = 348 eggs). Despite the differential use of hosts with regard to flange color, the frequencies of each were similar among nestling and juvenile Brown-headed Cowbirds. Likewise, the frequencies of each color did not differ significantly between the sexes. Therefore, we suggest that a flange color matching that of nestmates is not strongly selected for by hosts.La Variación del Color entre Polluelos de Molothrus ater no Refleja Éxito Diferencial al Ser Criados por Especies Hospederas en Texas
Flood Tides Affect Breeding Ecology of Two Sympatric Sharp-Tailed Sparrows
Authors: Shriver W. Gregory , Vickery Peter D. , Hodgman Thomas P. , Gibbs James P. 
Published: September 2019

AbstractBreeding synchrony with the lunar cycle has been reported for many marine organisms but is essentially unknown for birds. Most organisms shown to breed synchronously with the lunar cycle provide no parental care to young, and such explosive breeding assemblages are usually promiscuous. Saltmarsh Sharp-tailed Sparrows (Ammodramus caudacutus caudacutus) nest exclusively on salt marshes and are subjected to predictable, catastrophic flooding caused during flood tides every 28 days. Here, we show that Saltmarsh Sharp-tailed Sparrow males were nonterritorial and promiscuous and provided no parental care to young. Breeding behaviors of both sexes were synchronized with the lunar cycle. By contrast, males of a sympatric sister species, Nelson's Sharp-tailed Sparrow (A. nelsoni subvirgatus), consistently mate-guarded females, and breeding was not synchronized with the lunar cycle, yielding 21% lower reproductive success compared with Saltmarsh Sharp-tailed Sparrows. Saltmarsh and Nelson's sharp-tailed sparrows renested 2.9 ± 0.6 (SE) days and 10.3 ± 1.7 days after nest flooding, respectively. Patterns of vicariance between Nelson's and Saltmarsh sharp-tailed sparrows may explain the differences in social behavior and nesting ecology. Ancestral sharp-tailed sparrows diverged from Seaside Sparrows (A. maritimus) in tidal wetlands, and Nelson's Sharp-tailed Sparrows then diverged from Saltmarsh Sharp-tailed Sparrows in nontidal freshwater wetlands of interior North America. Nelson's Sharp-tailed Sparrows' range recently expanded into coastal salt marshes, where Saltmarsh Sharp-tailed Sparrows are better adapted to tidally influenced inundations. Adaptation to tidal flooding partially explains the evolution of the unique Saltmarsh Sharp-tailed Sparrow mating system.Las Inundaciones Mareales Afectan la Ecología Reproductiva de Dos Especies Simpátricas de Ammodramus
King Eider (Somateria Spectabilis) Brood Ecology: Correlates of Duckling Survival
Authors: Mehl Katherine R. , Alisauskas Ray T. 
Published: September 2019

AbstractEvents during duckling growth can influence waterfowl population dynamics. To gain insight into King Eider (Somateria spectabilis) brood ecology, we monitored 111 and 46 individually marked ducklings from broods of 23 and 11 radiomarked King Eiders during 2000 and 2001, respectively. We used capture-mark-resight data to model apparent survival of King Eider ducklings and broods, and multistratum analysis to estimate probabilities of (1) movement among habitats and (2) apparent survival of ducklings that used various habitats. In addition, we recorded length of stay for 7 and 18 radiomarked females with failed nesting attempts during 2000 and 2001, respectively. Complete loss of individual broods accounted for 84% of all duckling mortality (106 of 126 mortalities), with most brood loss (74%; 17 of 23 broods lost) within the first two days after hatch. Estimated apparent survival of ducklings to 24 days of age was 0.10 (95% CI: 0.05 to 0.15). Apparent survival of broods was estimated to be 0.31 (95% CI: 0.13 to 0.50). Our data suggested an interaction between female size and hatch date, whereby larger females whose ducklings also hatched earlier raised more ducklings than either small females or those with ducklings that hatched later. Overland brood movements ≥1 km occurred in both years, and survival was greatest for ducklings on smaller ponds away from the central nesting area at Karrak Lake, Nunavut. Females that experienced nest failure and total brood loss left the study area earlier than females with surviving ducklings.Écologie d'élevage des couvées de Somateria spectabilis : Corrélations avec la survie des canetons
Nest Light Environment and the Potential Risk of Common Cuckoo (Cuculus Canorus) Parasitism
Authors: Muñoz A. Román , Altamirano Maria , Takasu Fugo , Nakamura Hiroshi 
Published: September 2019

Abstract
Brood parasitism represents a significant cost in reproduction; thus, natural selection should favor the evolution of host defenses, which in turn may favor evolution of more sophisticated techniques by the parasite to overcome host defenses. These host defenses include egg rejection, attacking parasites near the nest, and avoiding parasitism by concealing nest sites. In all these antiparasitism strategies, nest light environment may play an important role. In the present study, the risk of Common Cuckoo (Cuculus canorus) parasitism for the Great Reed Warbler (Acrocephalus arundinaceus) was modeled in relation to the in situ nest light environment, from far ultraviolet (UV) to infrared (IR) radiation (280–1,100 nm), and nest situation and structure. The percentage of photosynthetically active radiation (PAR) plus IR radiation (400–1,100 nm) falling on the nest, maximum nest width, and distance between the nest and the nearest active conspecific neighbor were significantly related to the risk of parasitism. Photosynthetically active radiation alone explained 65% of variation in parasitism risk in the final model. Although solar radiation levels in nests were low (<4% for UV-B and UV-A radiation, 5% for PAR, and 22% for PAR plus IR radiation when cloudless), UV-B, UV-A, and visible-plus-IR radiation levels were significantly lower in nonparasitized nests. These findings provide the first evidence of a relationship between parasitism risk and nest concealment related to microhabitat light environment, with brighter nests suffering a higher risk of parasitism.
Ambiente Lumínico del Nido y el Riesgo Potencial de Parasitismo por Parte de Cuculus canorus
Validation of Thamnophilus Capistratus Lesson, 1840 (Passeriformes: Thamnophilidae)
Authors: Assis Claydson P. , Raposo Marcos A. , Stopiglia Renata , Parrini Ricardo 
Published: September 2019

Abstract
We reviewed the taxonomic status of Thamnophilus doliatus capistratus Lesson, 1840, which is endemic to eastern Brazil. The analyses of skins focused on plumage coloration and measurements. Morphometric skin analyses included descriptive statistics, analyses of variance, and discriminant-function analysis. The results provided a consistent morphological and morphometric diagnosis, and consequently validated Thamnophilus capistratus.
Validação de Thamnophilus capistratus Lesson, 1840 (Passeriformes: Thamnophilidae)
A New Species of Smoky Honeyeater (Meliphagidae: Melipotes) From Western New Guinea
Authors: Beehler Bruce M. , Prawiradilaga Dewi M. , de Fretes Yance , Kemp Neville 
Published: September 2019

AbstractWe describe a new species of smoky honeyeater from the Foja Mountains, an isolated range in western New Guinea (Papua Province, Indonesia). A common inhabitant of montane forest and forest-edge in this little-known north coastal range, this species possesses a fleshy pendant suborbital wattle, unique in the genus Melipotes, among other characteristics that distinguish it from all congeners. This fleshy wattle provides a morphological link between Melipotes and the monotypic genus Macgregoria, an alpine inhabitant of the Central Ranges of New Guinea, traditionally treated as a bird of paradise (e.g., Frith and Beehler 1998) but now regarded as the sister genus to Melipotes (Cracraft and Feinstein 2000). The presence of an endemic meliphagid species in the Foja Mountains highlights the biogeographic significance and conservation importance of this geographically isolated upland forest tract, which is also home to the endemic Golden-fronted Bowerbird (Amblyornis flavifrons) and Berlepsch's Parotia (Parotia berlepschi), a distinctive, recently rediscovered species of six-wired bird of paradise (B. M. Beehler unpubl. data).Una Especie Nueva de Melipotes (Meliphagidae) del Oeste de Nueva Guinea
Lifetime Reproductive Success of Female Eastern Kingbirds (Tyrannus Tyrannus): Influence of Lifespan, Nest Predation, and Body Size
Authors: Murphy Michael T. 
Published: September 2019

AbstractI report on the lifetime reproductive success (LRS) of female Eastern Kingbirds (Tyrannus tyrannus) in central New York. I investigated the major correlates of LRS and specifically tested the hypothesis that small body size yields reproductive benefits. Lifetime reproductive success varied widely: 15–20% of females failed to fledge young over their life, whereas 50% of young were fledged by 20% of females. Female lifespan varied between one and eight years, and females that died after one breeding season tended to be smaller-bodied than long-lived females (≥2 seasons). I therefore conducted analyses of LRS for the entire sample and for longer-lived females separately. As in other species, lifespan was the strongest predictor of LRS, followed by the proportion of eggs laid that resulted in fledged young (P). Lifetime reproductive success varied positively with clutch size and, as predicted, inversely with body size (i.e., tarsus length) of females. However, variance partitioning indicated that most variation in LRS was attributable to the effects of lifespan and P, but that a substantial negative covariance existed between lifespan and P. The latter result was consistent with experimental evidence of a cost of reproduction in Eastern Kingbirds. Analysis of the correlates of lifespan, P, and clutch size showed that over a female's lifetime, (1) the longest-lived birds fledged an intermediate proportion of the eggs that they laid, (2) the most productive birds were of intermediate wing length, and (3) females with small tarsi produced the largest clutches and lost the fewest nests to predators. Hence, although lifespan was the dominant influence on LRS, negative effects of large female size appeared to be expressed through the influence of body size on other demographic parameters that contribute to LRS.Éxito Reproductivo Completo de Vida de Hembras de Tyrannus tyrannus: Influencia de la Duración de la Vida, la Depredación de Nidos y el Tamaño Corporal