bluuebunny/crossref_metadata_2025 huggingface dataset:
Within-Territory Habitat Use and Microhabitat Selection by Male Cerulean Warblers (Dendroica Cerulea)
Authors: Barg Jennifer J. , Aiama Deviah M. , Jones Jason , Robertson Raleigh J.
Published: September 2019

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

Uso de Hábitat en los Territorios y Selección de Microhábitats por los Machos en Dendroica cerulea
Mixed-Grass Prairie Passerines Exhibit Weak and Variable Responses to Patch Size
Authors: Davis Stephen K. , Brigham R. Mark , Shaffer Terry L. , James Paul C.
Published: September 2019

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

Les Passereaux des Prairies Herbacées Montrent des Réponses Faibles et Variables en Réponse à la Taille des Parcelles d'Habitats
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

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

Concentrations 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

Most 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
Oiseaux d'Algeria-Birds of Algeria
Authors: Urban Emil K.
Published: September 2019

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.
Birds of South Asia: The Ripley Guide
Authors: Dickinson Edward C.
Published: September 2019

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.
Return of the Peregrine: A North American Saga of Tenacity and Teamwork
Authors: Anderson Daniel W.
Published: September 2019

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

We 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

We 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

Vocal 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

Habitat 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
Birds of Oregon: A General Reference
Authors: Frey Robert I. , Alexander John D.
Published: September 2019

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.
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

We 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

The 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

Males 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

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.
Ecological Consequences of Artificial Night Lighting
Authors: Crawford Robert L.
Published: September 2019

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.
Birds in European Cities
Authors: Donnelly Roarke
Published: September 2019

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

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

Seven 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
Territoriality, Prospecting, and Dispersal in Cooperatively Breeding Micronesian Kingfishers (Todiramphus Cinnamominus Reichenbachii)
Authors: Kesler Dylan C. , Haig Susan M.
Published: September 2019

We investigated territoriality, prospecting, and dispersal behavior in cooperatively breeding Pohnpei Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii) throughout the annual cycle using radiotelemetry and color-band resights. Mean home-range size was 6.3 ha and territories were 8.1 ha. Within territories, Micronesian Kingfishers shared 63% of their home-range space with coterritorial occupants, and 3% was shared with extraterritorial conspecifics. Birds on cooperative territories had larger home ranges that overlapped more with coterritory occupants' home ranges than birds in pair-held territories. Despite evidence suggesting that resources necessary for survival and reproduction occurred on each territory, Micronesian Kingfishers of all age and sex classes made extraterritorial prospecting movements. Prospecting was rare; it comprised only 4.3% of our observations. When birds departed on forays, they were gone for ∼1.9 h and returned to home territories before sunset. Prospecting by dominant birds was temporally correlated with courtship and nest initiation, and birds were observed at neighboring nest sites with opposite-sex conspecifics during the period when females were available for fertilization. Juveniles and helpers prospected throughout the year and made repeated homesteading movements to dispersal destinations before dispersing. Mean dispersal distance for radiomarked individuals was 849 m. Results suggest that prospecting in Micronesian Kingfishers is a complex behavior that provides information for dispersal decisions and familiarity with dispersal destinations. Additionally, extraterritorial movements may provide covert opportunities for reproduction, which have potential to profoundly influence the distribution of fitness among helper and dominant Micronesian Kingfishers.

Territorialité, prospection et dispersion chez des Todiramphus cinnamominus reichenbachii présentant une reproduction coopérative
Ancestral State Reconstruction of Migration: Multistate Analysis Reveals Rapid Changes in New World Orioles (Icterus SPP)
Authors: Kondo Beatrice , Omland Kevin E.
Published: September 2019

During the past century, numerous theoretical articles explored the evolution of seasonal migration in birds; many of these focused on environmental or social conditions that may have led to the origin of migration. More recent work has focused not on the origin of migration, but on changes in migratory behavior that have occurred in modern species and their immediate ancestors. We used a novel approach, a multistate ancestral state reconstruction of migration, to examine patterns of migratory evolution in the New World orioles (Icterus spp.). Both the multistate and binary reconstructions indicated repeated gains in migration. However, the multistate method revealed details of how migration may be gained that the standard binary-state reconstructions would not have shown. Our maximum-likelihood reconstruction, using branch lengths based on a molecular phylogeny, suggested multiple instances of rapid gain of migration. Furthermore, we found that every migratory species' migration type differed from that of its closest relatives. Surprisingly, no partially migratory species was closely related to a fully migratory species. These novel patterns involving gain of migration demonstrate the utility of multistate ancestral reconstruction for examining changes in migratory behavior in closely related birds.

Reconstrucción de Estados Ancestrales de la Migración: Análisis con Múltiples Estados de Carácter Revelan Cambios Rápidos en los Orioles del Nuevo Mundo (Icterus spp.)
Environmental and Spatial Segregation of Leks Among Six Co-Occurring Species of Manakins (Pipridae) in Eastern Ecuador
Authors: Loiselle Bette A. , Blake John G. , Durães Renata , Ryder T. Brandt , Tori Wendy
Published: September 2019

Environmental correlates and geographic spacing of leks were compared for six species of manakins (Pipridae) on two 100-ha study plots in eastern Ecuador. The “hotspot” hypothesis of lek evolution suggests that males should aggregate where females are most likely to be encountered. For ecologically similar species that co-occur at a site, leks are predicted to be clustered in space and, thus, to overlap in macroscale environmental characteristics. The geographic spacing and environmental characteristics of lek sites we observed were inconsistent with the hotspot hypothesis for lek evolution. In general, little geographic overlap occurred among leks, and geographic spacing of leks among heterospecifics more closely fit a regular than a clumped pattern. Further, environmental conditions of leks varied among species with respect to elevation and topography. Leks of some species were more likely to occur on hilltops or ridge tops (e.g., Machaeropterus regulus, Pipra erythrocephala), whereas others appeared to prefer highly dissected drainages (e.g., P. pipra), relatively flat terrain near streams (e.g., Chiroxiphia pareola), or seasonally inundated forests (e.g., P. filicauda). Using randomly placed leks, we found evidence that certain lek environments may be limited, which is consistent with observed levels of population abundances on the two plots. Such environmental limits may constrain lek placement and size. Further study is needed to determine the reproductive implications of placing leks in apparently suboptimal environments, though such compromises may reflect males making the best of a bad situation.

Segregación Ambiental y Espacial de las Asambleas de Cortejo Entre Seis Especies Simpátricas de Saltarines (Pipridae) en el Oriente de Ecuador
Partitioning Risk Among Different Causes of Nest Failure
Authors: Etterson Matthew A. , Nagy Laura R. , Robinson Tara Rodden
Published: September 2019

Nest predation and nest parasitism receive the most attention as causes of nest failure for North American songbirds. Yet for many populations, interspecific competition, adverse weather, abandonment, nestling starvation, and egg failure may also be significant causes of nest failure. Despite the long interest in differential failure, serious challenges remain in the estimation of separate probabilities of nest failure from different causes. Apparent rates of failure suffer from at least two sources of bias: heterogeneous ages at discovery and classification error. We developed maximum-likelihood estimators for cause-specific daily probabilities of nest failure. We further show how the estimators can be extended to include classification error, if known. Finally, we demonstrate a simple application to Loggerhead Shrikes (Lanius ludovicianus), Tree Swallows (Tachycineta bicolor), Violet-green Swallows (T. thalassina), and Western Bluebirds (Sialia mexicana). Daily probabilities of survival were lower for the Loggherhead Shrike (0.978 ± 0.004) than for any of the three cavity-nesting species (range: 0.989 ± 0.002 − 0.993 ± 0.001). Weather was an important cause of nest failure for Loggerhead Shrikes (0.15 ± 0.05 overall). Conversely, competition among secondary cavity-nesters was not an important contributor to nest failure (range: 2–5% of nest failures) for bluebirds or swallows. Our estimator differs from others by allowing multiple fates to be modeled as separately estimated parameters rather than as covariates to a single estimated failure probability. Thus, our estimator should be viewed as an important complement to existing methods.

División del Riesgo Entre Diferentes Causas de Fracaso Durante la Nidificación
Structure and Dynamics of The Hybrid Zone Between Black-Capped Chickadee (Poecile Atricapillus) and Carolina Chickadee (P. Carolinensis) in Southeastern Pennsylvania
Authors: Reudink Matthew W. , Mech Stephen G. , Mullen Sean P. , Curry Robert L.
Published: September 2019

Analysis of the structure and stability of a hybrid zone can serve as a starting point for examining mechanisms that influence spatial and evolutionary relationships between species. Recent studies of the hybrid zone between Black-capped Chickadee (Poecile atricapillus) and Carolina Chickadee (P. carolinensis) have suggested that genetic introgression is limited to a narrow zone, while also reinforcing the conclusion that the line of contact between these parapatrically distributed species is now shifting northward. We investigated the structure, position, and recent movement of the chickadee hybrid zone in southeastern Pennsylvania. Using selectively neutral microsatellite DNA markers, along with mitochondrial DNA haplotypes, we documented large differences in genetic composition among three populations ≤65 km apart where we sampled large numbers of breeding residents during 1998–2003. Genetic results indicate that the three sites support a population of Carolina Chickadees (Great Marsh), a population in which most individuals exhibit evidence of hybridization (Nolde Forest), and a population comprising mostly Black-capped Chickadees but with evidence of hybridization now taking place (Hawk Mountain). The patterns within the Nolde Forest population suggest that selection against hybrids may not be as strong as has been concluded from studies in other parts of the chickadee hybrid zone. Comparison of mitochondrial and nuclear genotypes between samples collected ≈15 years apart suggest that the northern edge of the hybrid zone shifted by ≈20 km over this interval, with hybridization now occurring as far north as the Kittatinny Ridge and beyond, where only Black-capped Chickadee genotypes were previously detectable. Our data and historical accounts suggest that the hybrid zone, now ≈50 km wide, may have become wider while also shifting northward. These results support the hypothesis that Carolina Chickadees enjoy a selective advantage during hybridization with Black-capped Chickadees, but both the proximate mechanisms and ultimate causes remain to be investigated.

Structure et dynamique de la zone d'hybridation entre Poecile atricapillus et P. carolinensis dans le sud-est de la Pennsylvanie
Revision of Molt and Plumage Terminology in Ptarmigan (Phasianidae: Lagopus SPP.) Based on Evolutionary Considerations
Authors: Pyle Peter
Published: September 2019

By examining specimens of ptarmigan (Phasianidae: Lagopus spp.), I quantified three discrete periods of molt and three plumages for each sex, confirming the presence of a definitive presupplemental molt. A spring contour molt was significantly later and more extensive in females than in males, a summer contour molt was significantly earlier and more extensive in males than in females, and complete summer-fall wing and contour molts were statistically similar in timing between the sexes. Completeness of feather replacement, similarities between the sexes, and comparison of molts with those of related taxa indicate that the white winter plumage of ptarmigan should be considered the basic plumage, with shifts in hormonal and endocrinological cycles explaining differences in plumage coloration compared with those of other phasianids. Assignment of prealternate and presupplemental molts in ptarmigan necessitates the examination of molt evolution in Galloanseres. Using comparisons with Anserinae and Anatinae, I considered a novel interpretation: that molts in ptarmigan have evolved separately within each sex, and that the presupplemental and prealternate molts show sex-specific sequences within the definitive molt cycle.

Revisión de la Terminología de la Muda y el Plumaje en Lagopus spp. (Phasianidae) con Base en Consideraciones Evolutivas
A Molecular Evaluation of the North American “Grassland” Sparrow Clade
Authors: Klicka John , Spellman Garth M.
Published: September 2019

Because they share several morphological and ecological characters, the North American sparrow (Emberizidae) genera Ammodramus, Passerculus, and Xenospiza have historically been considered members of a well-defined “grassland” sparrow assemblage. Relationships among the 11 members of this group have been the subject of much taxonomic debate, yet no comprehensive molecular assessment of relationships has been done. We investigated these relationships using mitochondrial DNA sequence data that included complete cytochrome-b and ND2 genes. Phylogenetic reconstructions derived via parsimony, likelihood, and Bayesian methods were congruent. The grassland sparrows, as presently configured, are polyphyletic. Pooecetes gramineus, Amphispiza belli (but not A. quinquestriata and A. bilineata), Oriturus superciliosus, and all three species of Melospiza are included in a reconfigured clade, whereas the traditional forms of Ammodramus savannarum, humeralis, and aurifons are placed well outside of these. Within the clade of interest, Ammodramus remains polyphyletic, with leconteii, maritimus, nelsoni, and caudacutus forming a well-resolved clade apart from henslowii and bairdii. The latter are in another strongly supported clade that also includes Passerculus and a Xenospiza-Melozpiza sister pairing. Pooecetes, Amphispiza (belli), and Oriturus represent early lineages in this clade that today have no close living relatives. The polyphyly of the genus Ammodramus is likely the result of morphological convergence attributable to similar adaptive responses to the occupation of similar habitats. In general, the morphological and ecological factors that have defined the grassland sparrows are poor indicators of relatedness. Taxonomic revisions are suggested.

Evaluación Molecular del Clado de Gorriones de Pastizales de Norte América
Molecular Systematics and Historical Biogeography of the Rock-Thrushes (Muscicapidae: Monticola)
Authors: Outlaw Robert K. , Voelker Gary , Outlaw Diana C.
Published: September 2019

The genus Monticola consists of 13 putative species with distributions throughout Eurasia and the sub-Saharan region of Africa. As such, this genus provides an excellent model with which to explore historical intercontinental movements and forces driving speciation in southern Africa. To address these questions, we reconstructed a hypothesis of species relationships using the mitochondrial ND2 and cytochrome-b genes. Monticola forms a well-supported, monophyletic clade within the avian family Muscicapidae. Our results support previous studies suggesting that the Malagasy genus Pseudocossyphus be subsumed into Monticola, and suggest that several of the Malagasy species (notably M. bensoni and M. erythronotus) are not valid. Sequence data, along with morphological and distributional evidence, support the elevation of M. pretoriae to species status. Historical biogeographic analyses suggest an area of origin for Monticola in the arid region of northern Africa plus Saudi Peninsula or the African savanna, or both. Determination of speciation timing suggests that Monticola arose ≈5.5 mya, with subsequent lineage splits occurring throughout the Pliocene and Pleistocene. We propose that climate-driven ecological vicariance as well as dispersal were important in the biogeographic history of this group and are responsible for present-day species relationships and distributions.

Systématique moléculaire et biogéographie historique des monticoles (Muscicapidae: Monticola)
Population-Specific Demographic Estimates Provide Insights into Declines of Lark Buntings (Calamospiza Melanocorys)
Authors: Yackel Adams Amy A. , Skagen Susan K. , Savidge Julie A.
Published: September 2019

Many North American prairie bird populations have recently declined, and the causes of these declines remain largely unknown. To determine whether population limitation occurs during breeding, we evaluated the stability of a population of prairie birds using population-specific values for fecundity and postfledging survival. During 2001-2003, we radiomarked 67 female Lark Buntings (Calamospiza melanocorys) to determine annual fecundity and evaluate contributing factors such as nest survival and breeding response (number of breeding attempts and dispersal). Collectively, 67 females built 112 nests (1.67 ± 0.07 nests female−1 season−1; range: 1–3); 34 were second nests and 11 were third nests. Daily nest survival estimates were similar for initial and later nests with overall nest survival (DSR19) of 30.7% and 31.7%, respectively. Nest predation was the most common cause of failure (92%). Capture and radiomarking of females did not affect nest survival. Lark Bunting dispersal probabilities increased among females that fledged young from initial nests and females that lost their original nests late in the season. Conservative and liberal estimates of mean annual fecundity were 0.96 ±0.11 and 1.24 ± 0.09 female offspring per female, respectively. Given the fecundity and juvenile-survival estimates for this population, annual adult survival values of 71–77% are necessary to achieve a stable population. Because adult survival of prairie passerines ranges between 55% and 65%, this study area may not be capable of sustaining a stable population in the absence of immigration. We contrast our population assessment with one that assumes indirect values of fecundity and juvenile survival. To elucidate limiting factors, estimation of population-specific demographic parameters is desirable. We present an approach for selecting species and areas for evaluation of population stability.

Las Estimaciones Demográficas Poblacionales Específicas Brindan Pistas sobre la Disminución de Calamospiza melanocorys