bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Geographic-Information-System Approach to Estimating the Origin of Migratory Raptors in North America Using Stable Hydrogen Isotope Ratios in Feathers
Authors: Lott Casey A. , Smith Jeff P. 
Published: September 2019

Abstract
Analysis of stable hydrogen isotope ratios in feathers (δDf) is a promising method for investigating population connectivity in migratory birds. Stable hydrogen isotope ratios in precipitation (δDp) vary across North America with respect to latitude, elevation, and seasonal air-mass trajectories. A strong relationship between δDf and δDp at locations of feather growth has been documented for several bird species. Some studies have used measurements of δDf to plot the origins of migrants on maps of long-term weighted-average, growing-season North American δDp (hereafter “δDp maps”) using the observed relationship between δDf and δDp from a reference sample of known-origin birds. The accuracy of this method depends on the strength of the δDf and δDp relationship and accuracy of the δDp maps. Recently, a high-resolution (1-km2) model of North American δDp was published (Meehan et al. 2004) that accounts for the effect of elevation on δDp where previous models did not. We compared δDf measurements from a geographically diverse sample of 264 raptor feathers with δDp estimates for feather-sample locations. We documented a strong relationship between raptor δDf and δDp across North America. However, we also documented substantial regional variation in this relationship. We created a “base map” of North American raptor δDf that incorporated the regional variation described by our sample. We plotted δDf values from migrant Sharp-shinned Hawks (Accipiter striatus) captured in eastern Nevada directly on this map to demonstrate how it can be used to view the origins of migrants.
Un Procedimiento Basado en Sistemas de Información Geográfica para Estimar el Origen de las Aves Rapaces Migratorias en Norte América Usando los Cocientes de Isótopos Estables de Hidrógeno Presentes en las Plumas
Dietary Effects on Prediction of Body Mass Changes in Birds by Plasma Metabolites
Authors: Cerasale David J. , Guglielmo Christopher G. 
Published: September 2019

AbstractConcentrations of plasma metabolites, including triglyceride, glycerol, and B-OH butyrate, can be used to determine refueling performance of migratory birds. We tested the effects of diet type and diet lipid content on the predictive relationships between metabolites and body mass changes in three species of passerines in captivity. In addition, we tested whether measurement of plasma phospholipids improved predictions of mass change. Rate of mass change was positively related to triglycerides in a captive frugivore (Cedar Waxwing; Bombycilla cedrorum) and a granivore (White-crowned Sparrow; Zonotrichia leucophrys). B-OH butyrate was negatively and nonlinearly related to mass change in Cedar Waxwings and White-crowned Sparrows. Glycerol was negatively related to mass change in Cedar Waxwings but not in White-crowned Sparrows. Mass change was positively related to triglycerides and negatively related to B-OH butyrate in Yellow-rumped Warblers (Dendroica coronata). There was no effect of diet lipid content (9% vs. 28% dry mass) on these predictive relationships. Plasma phospholipids were positively related to mass change in White-crowned Sparrows, but negatively related to mass change in Yellow-rumped Warblers and not related to mass change in Cedar Waxwings. Measurement of phospholipids did not improve prediction of mass change by metabolite profiles. Nevertheless, plasma metabolite profiles are predictive of short- term mass changes in captive birds regardless of diet type or diet lipid content, and can provide valuable information on refueling performance in studies of stopover ecology.Efectos de la Dieta sobre las Predicciones de los Cambios en el Peso Corporal de Aves por medio de Metabolitos Plasmáticos
Helper Effects on Offspring Production in Cooperatively Breeding Brown Jays (Cyanocorax Morio)
Authors: Williams Dean A. , Hale Amanda M. 
Published: September 2019

AbstractMost studies of cooperatively breeding species have revealed that indirect fitness gains from helping are lower than benefits gained from direct reproduction. Exceptions to this “best of a bad job” strategy are rare. Brown Jays (Cyanocorax morio) in Monteverde, Costa Rica, live in large groups (mean = 10 individuals) and have never been observed to breed as unaided pairs. Helpers provide a substantial percentage (70%) of all nestling feedings. Together, these observations suggest that helping may be crucial for reproductive success in this population. We used multivariate models to examine the effect of helpers on offspring production using a long-term data set. Data on nest-site success and brood reduction suggested that predation was the major cause of nesting failure. Nesting in an isolated tree was the major determinant of successful nestling production, and our data indicate that small groups (less than 9 individuals) may not be able to acquire or defend territories that contain suitable nesting sites. The number of juveniles (young surviving 30 days after leaving the nest) and yearlings was positively related to group size, even after removing groups that nested only in non-isolated trees. Small groups were also more likely than large groups to have total reproductive failure in a season. Helpers may increase juvenile survival by reducing predation, increasing juvenile condition, or providing learning opportunities for foraging and antipredator behaviors. Helpers on their natal territories receive some indirect benefits, though these are low compared with independent breeding. Immigrant male helpers may benefit primarily by gaining future breeding opportunities. Delayed benefits related to territory inheritance and dispersal coalitions may be the best explanation for helping in this population.Efectos de los Ayudantes sobre la Producción de Progenie en Cyanocorax morio, una Especie con Cría Cooperativa
Return of the Peregrine: A North American Saga of Tenacity and Teamwork
Authors: Anderson Daniel W. 
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.
Do Nectar- and Fruit-Eating Birds Have Lower Nitrogen Requirements Than Omnivores? an Allometric Test
Authors: Tsahar Ella , Arad Zeev , Izhaki Ido , Martínez del Rio Carlos 
Published: September 2019

AbstractWe used an allometric approach to compare the minimum nitrogen requirements (MNR) and the total endogenous nitrogen loss (TENL) of nectar- and fruit-eating birds with those of omnivorous birds. These two parameters were 4× higher in omnivores than in nectarivores and frugivores. In nectarivorous-frugivorous birds, MNR was 152.8 mg N kg−0.76 day−1; in omnivorous birds, it was 575.4 mg N kg−0.76 day−1. Similarly, TENL was 54.1 mg N kg−0.69 day−1 in nectarivores-frugivores, and 215.3 mg N kg−0.69 day−1 in omnivores. The residuals of the allometric relationships between TENL and MNR and body mass were positively correlated, which suggests that a large proportion of the interspecific variation in MNR is explained by variation in TENL. Although our results show that nectar- and fruit-eating birds have low nitrogen requirements, the mechanisms that these animals use to conserve nitrogen remain unclear.¿Tienen las Aves Nectrarívoras y Frugívoras Requerimientos de Nitrógeno Menores que las Omnívoras? Una Prueba Alométrica
Genetic Structure of Mexican Spotted Owl (Strix Occidentalis Lucida) Populations in a Fragmented Landscape
Authors: Barrowclough George F. , Groth Jeff G. , Mertz Lisa A. , Gutiérrez R. J. 
Published: September 2019

AbstractWe used mitochondrial DNA control-region sequences to investigate the genetic structure of Mexican Spotted Owl (Strix occidentalis lucida) populations in the southwestern United States. This subspecies is federally listed as threatened, and its preferred habitat is naturally fragmented. We found that intrapopulation genetic diversity was high in all but the southeastern Arizona “sky island” populations, where it was variable. Genetic variance partitioning indicated that ≈17% of the variation was distributed among populations and 7.5% was distributed among physiographic regions. Patterns of genetic correlation with geographic distance indicated that gene flow was substantial among populations within the relatively continuous habitat zone of the Mogollon Rim-Upper Gila Mountains in central Arizona and west-central New Mexico. However, there was significant isolation-by-distance elsewhere, and estimates of genetic divergence increased exponentially with geographic distance among fragmented populations on the scale of a few hundreds of kilometers; this implies that gene flow is restricted among those habitat fragments. Genetic heterogeneity among southeastern Arizona populations suggest that they have regularly received immigrants from the central Arizona populations. The Colorado population either was larger than thought or, more likely, has continuously received immigrants from elsewhere and is not a self-sustaining population.Estructura Genética de las Poblaciones de Strix occidentalis lucida en un Paisaje Fragmentado
Vocalizations and Associated Behaviors of the Sombre Hummingbird (Aphantochroa Cirrhochloris) and the Rufous-Breasted Hermit (Glaucis Hirsutus)
Authors: Ferreira Adriana R. J. , Smulders Tom V. , Sameshima Koichi , Mello Claudio V. , Jarvis Erich D. 
Published: September 2019

AbstractVocal behavior in tropical hummingbirds is a new area of study. Here, we present findings on the vocalizations and associated behaviors of two species: Sombre Hummingbird (Aphantochroa cirrhochloris) and Rufous-breasted Hermit (Glaucis hirsutus). These are the only hummingbirds in which the brain areas activated by singing have been demonstrated. They are also among the basal species of their respective subfamilies, Trochilinae and Phaethornithinae and, thus, represent early stages in the evolution of hummingbird vocal communication. We found that the two species exhibit distinctive vocalizations and behaviors. Sombre Hummingbird calls had more modulation and were often used during agonistic interactions, whereas Rufous-breasted Hermit calls had higher pitch and purer tones and were produced in less aggressive interactions. Sombre Hummingbird song was highly stereotyped in syllable structure and syntax, whereas Rufous-breasted Hermit song was highly variable. Comparative analysis points to consistent similarities in use of vocalizations by the Sombre Hummingbird and other trochilines, and by the Rufous-breasted Hermit and other phaethornithines. We hypothesize that differences in vocal behavior between hummingbird lineages arise as adaptations to their foraging strategies.Vocalizaciones y Comportamientos Asociados de Aphantochroa cirrhochloris y Glaucis hirsutus
Patch Colonization Dynamics in Carolina Chickadees (Poecile Carolinensis) in a Fragmented Landscape: A Manipulative Study
Authors: Groom Jeremiah D. , GrubbJr Thomas C. 
Published: September 2019

AbstractHabitat and landscape features that influence the rate of interpatch movement and colonization may determine the likelihood that a species will persist in fragmented landscapes. We simulated patch extinction by removing Carolina Chickadees (Poecile carolinensis) from woodland fragments in an Ohio agricultural landscape in January 2002. We then monitored the woodlands to determine their dates of reoccupation and subsequent use for breeding by the birds. All woodlots were eventually reoccupied, regardless of size or degree of isolation, but woodlots in less-forested landscapes connected to other woodland by habitat corridors were reoccupied sooner than unconnected woodlots. Reoccupation was more likely to occur during periods of mild wind chill. Following reoccupation, individual Carolina Chickadees were more often temporarily absent from smaller woodlots, which suggests that they may have used woodlots that insufficiently met foraging or breeding requirements. Carolina Chickadees were more likely to remain to breed in larger woodlots. Results indicate that habitat connectivity may affect the tendency of this species to move through a fragmented landscape. Habitat corridors may be important management tools for maintaining movement of animals between patches.Dinámica de Colonización de Parches en Poecile carolinensis en Paisajes Fragmentados: Un Estudio de Manipulación
Spatial and Temporal Migration Patterns of Wilson’s Warbler (Wilsonia Pusilla) in the Southwest as Revealed by Stable Isotopes
Authors: Paxton Kristina L. , Van Riper Charles , Theimer Tad C. , Paxton Eben H. 
Published: September 2019

AbstractWe used stable hydrogen isotopes (δD) to identify the breeding locations of Wilson’s Warbler (Wilsonia pusilla) migrating through five sites spanning a cross-section of the species’ southwestern migration route during the springs of 2003 and 2004. Determining the temporal and spatial patterns of migration and degree of population segregation during migration is critical to understanding long-term population trends of migrant birds. At all five migration sites, we found a significant negative relationship between the date Wilson’s Warblers passed through the sampling station and δD values of their feathers. These data were consistent with a pattern of “leap-frog” migration, in which individuals that bred the previous season at southern latitudes migrated through migration stations earlier than individuals that had previously bred at more northern latitudes. We documented that this pattern was consistent across sites and in multiple years. This finding corroborates previous research conducted on Wilson’s Warbler during the fall migration. In addition, mean δD values became more negative across sampling stations from west to east, with the mean δD values at each station corresponding to different geographic regions of the Wilson’s Warblers’ western breeding range. These data indicate that Wilson’s Warblers passing through each station represented a specific regional subset of the entire Wilson’s Warbler western breeding range. As a result, habitat alterations at specific areas across the east-west expanse of the bird’s migratory route in the southwestern United States could differentially affect Wilson’s Warblers at different breeding areas. This migration information is critical for management of Neotropical migrants, especially in light of the rapid changes presently occurring over the southwestern landscape.Patrones Espaciales y Temporales de la Migración de Wilsonia pusilla en el Sudoeste Detectados Mediante Isótopos Estables
Age Ratios as Estimators of Productivity: Testing Assumptions on a Threatened Seabird, The Marbled Murrelet (Brachyramphus Marmoratus)
Authors: Peery M. Zachariah , Becker Benjamin H. , Beissinger Steven R. 
Published: September 2019

AbstractThe ratio of hatch-year (HY) to after-hatch-year (AHY) individuals (HY:AHY ratio) can be a valuable metric for estimating avian productivity because it does not require monitoring individual breeding sites and can often be estimated across large geographic and temporal scales. However, rigorous estimation of age ratios requires that both young and adult age classes are sampled in an unbiased manner, an assumption that is rarely tested. We estimated HY:AHY ratios for Marbled Murrelets (Brachyramphus marmoratus), a threatened seabird, using at-sea surveys and captures to assess whether age-specific differences in behavior and distribution result in biased productivity estimates in central California. AHY and HY Marbled Murrelets were distributed similarly at sea, and HY individuals did not congregate in nursery areas. Moreover, dispersal by radiomarked AHY Marbled Murrelets out of our survey area occurred at a low rate, and AHY densities were constant over the survey period, which suggests that AHY immigration and emigration did not significantly bias productivity estimates. HY density increased linearly over the survey period as expected if little dispersal occurred, which suggests that productivity estimates were not significantly biased by HY dispersal. Finally, simulation analyses indicated that annual variation in the timing of breeding resulted in only small biases in HY:AHY ratios. HY:AHY ratios were corrected for the proportion of AHY Marbled Murrelets that were incubating and the proportion of HY individuals that had not fledged at the time of sampling. Mean corrected HY:AHY ratios were low on the basis of both at-sea surveys conducted from 1996 to 2003 (0.032; SE = 0.011) and captures conducted from 1999 to 2003 (0.037; SE = 0.028), implying that productivity was poor in central California. Estimating age ratios may be an effective way of monitoring changes in reproductive success and identifying environmental factors that affect Marbled Murrelet populations, though tests of assumptions are needed in other regions.Le Rapport des Âges comme Estimateur de la Productivité: Tester les Hypothèses avec un Oiseau de Mer Menacé, Brachyramphus marmoratus
Mound and Mate Choice in a Polyandrous Megapode: Females Lay More and Larger Eggs in Nesting Mounds With the Best Incubation Temperatures
Authors: Göth Ann 
Published: September 2019

AbstractMales of the polyandrous Australian Brush-turkey (Alectura lathami) build mounds of leaf litter, in which incubation heat is produced by microbial decomposition. Females lay eggs singly, at intervals of several days, over many months. For each egg, they select an incubation mound in which to lay, and they then typically copulate with the male mound-owner; mound choice is, thus, usually equal to mate choice. Freed from incubation and maternal care, these females can invest considerable time and energy in assessing and choosing their potential mates. Low or high incubation temperatures inside the mounds have negative effects on embryos and chicks, and temperatures vary considerably both between and within mounds. Here, I show that mounds with mean incubation temperatures ranging from approximately 32°C to 35°C received more eggs than cooler or warmer mounds. Similarly, when the size of each egg was compared with its temperature when found in the mound, larger eggs were deposited mainly in mound material at temperatures between approximately 32°C and 35°C, whereas smaller eggs were laid at temperatures above and below this range. Egg size was included as a factor describing female mate choice, because egg size in relation to body size is exceptionally large, which indicates considerable female investment. Overall, these results suggest that the temperature in the males’ incubation mounds considerably affects female mate choice.Selección del Montículo y de la Pareja en un Megápodo Poliándrico: Las Hembras Ponen Más y Mayores Huevos en los Montículos de Nidificación con las Mejores Temperaturas de Incubación
A Carriker Trilogy: Chapters in a Saga of Neotropical Ornithology
Authors: Olson Storrs L. 
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.
Phylogenetic Position of the New World Quail (Odontophoridae): Eight Nuclear Loci and Three Mitochondrial Regions Contradict Morphology and the Sibley-Ahlquist Tapestry
Authors: Cox W. Andrew , Kimball Rebecca T. , Braun Edward L. 
Published: September 2019

Abstract
The evolutionary relationship between the New World quail (Odontophoridae) and other groups of Galliformes has been an area of debate. In particular, the relationship between the New World quail and guineafowl (Numidinae) has been difficult to resolve. We analyzed >8 kb of DNA sequence data from 16 taxa that represent all major lineages of Galliformes to resolve the phylogenetic position of New World quail. A combined data set of eight nuclear loci and three mitochondrial regions analyzed with maximum parsimony, maximum likelihood, and Bayesian methods provide congruent and strong support for New World quail being basal members of a phasianid clade that excludes guineafowl. By contrast, the three mitochondrial regions exhibit modest incongruence with each other. This is reflected in the combined mitochondrial analyses that weakly support the Sibley-Ahlquist topology that placed the New World quail basal in relation to guineafowl and led to the placement of New World quail in its own family, sister to the Phasianidae. However, simulation-based topology tests using the mitochondrial data were unable to reject the topology suggested by our combined (mitochondrial and nuclear) data set. By contrast, similar tests using our most likely topology and our combined nuclear and mitochondrial data allow us to strongly reject the Sibley-Ahlquist topology and a topology based on morphological data that unites Old and New World quail.
Posición Filogenética de las Codornices del Nuevo Mundo (Odontophoridae): Ocho Loci Nucleares y Tres Regiones Mitocondriales Contradicen la Morfología y la Filogenia de Sibley y Ahlquist
Fossil Passerines From the Early Pliocene of Kansas and the Evolution of Songbirds in North America
Authors: Emslie Steven D. 
Published: September 2019

AbstractSeven living species of passerines are identified or tentatively identified from the early Pliocene Fox Canyon locality (4.3–4.8 mya), Rexroad Formation, Meade Basin, southwestern Kansas. All seven species occur in Kansas today, primarily as winter residents or transients, and their migratory behavior may extend to the early Pliocene as well. A review of all known passerines from the Neogene of North America indicates that many modern taxa began to appear in the early Pliocene, much earlier than previously believed. This fossil evidence agrees with some mitochondrial DNA analyses for the estimated age of divergence for living species of longspurs (Calcarius lapponicus and C. mccownii), but similar estimates for the divergence of C. ornatus using cytochrome-b analyses is at least 3 my younger than indicated by the fossil evidence. The fossil songbirds, as well as other vertebrate taxa from the Meade Basin, also indicate a paleoenvironment of short-grass prairie and shrubland with wetlands and ponds nearby, similar to that found in the area today. This prairie-steppe habitat first appeared in the Meade Basin by the early Pliocene and remained relatively stable until the Pleistocene, when it periodically appeared and disappeared with climate change. High seasonal productivity associated with this habitat in the early Pliocene may have promoted migratory behavior and speciation events in songbirds during a period of relative climatic stasis.Paserinos Fósiles del Plioceno Temprano de Kansas y la Evolución de las Aves Canoras en Norte América