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Anticipating species’ responses to environmental change is a pressing mission in biodiversity conservation. Despite decades of research investigating how climate change may affect population sizes, historical context is lacking and the traits which mediate demographic sensitivity to changing climate remain elusive. We use whole-genome sequence data to reconstruct the demographic histories of 263 bird species over the past million years and identify networks of interacting morphological and life-history traits associated with changes in effective population size (Ne) in response to climate warming and cooling. Our results identify direct and indirect effects of key traits representing dispersal, reproduction, and survival on long-term demographic responses to climate change, thereby highlighting traits most likely to influence population responses to on-going climate warming.One-Sentence SummaryInteracting traits influence sensitivity of bird population sizes to climate warming and cooling over the past million years.

Biotic homogenization-increasing similarity of species composition among ecological communities-has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (similar to 30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (similar to 20,000-14,000 ybp). From similar to 10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at similar to 10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (similar to 2,000-1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back similar to 10,000 years.

Extinction leads to restructuring By most accounts, human activities are resulting in Earth's sixth major extinction event, and large-bodied mammals are among those at greatest risk. Loss of such vital ecosystem components can have substantial impacts on the structure and function of ecological systems, yet fully understanding these effects is challenging. Tóth et al. looked at the loss of large-bodied mammals in the Pleistocene epoch to identify potential community assembly effects. They found that the demise of large mammals led to a restructuring and a shift from biotic to abiotic drivers of community structure. Understanding past changes may help predict the community-level effects of the extinctions we are currently driving. Science , this issue p. 1305

Limnothlypis swainsonii (Swainson's Warbler) readily colonizes novel habitat formations that meet basic requirements for understory stem density and visual screening. Little is known about the warbler's behavioral response to naturalized populations of introduced plants. I surveyed the incidence of introduced invasive Ligustrum spp. (privet) and native Arundinaria spp. (cane) on breeding territories (n = 590) of Swainson's Warbler in the southeastern United States. Privet occurred frequently on territories in Mississippi (65.0%), Alabama (55.7%), Louisiana (52.8%), and Texas (39.5%). Territories with privet (49.6% of total) were observed in 90 counties and parishes. The survey revealed numerous instances of warbler territories located in near-monocultures of Ligustrum sinense (Chinese Privet). Territories with cane (33.1% of total) were observed in 72 counties and parishes. In a broader context, the survey data suggest that Swainson's Warbler populations have rapidly adapted to invasive privets, which are physiognomically similar to several native thicket-forming shrubs.

Background Stereotyped sunning behaviour in birds has been hypothesized to inhibit keratin-degrading bacteria but there is little evidence that solar irradiation affects community assembly and abundance of plumage microbiota. The monophyletic New World vultures (Cathartiformes) are renowned for scavenging vertebrate carrion, spread-wing sunning at roosts, and thermal soaring. Few avian species experience greater exposure to solar irradiation. We used 16S rRNA sequencing to investigate the plumage microbiota of wild individuals of five sympatric species of vultures in Guyana. Results The exceptionally diverse plumage microbiotas (631 genera of Bacteria and Archaea) were numerically dominated by bacterial genera resistant to ultraviolet (UV) light, desiccation, and high ambient temperatures, and genera known for forming desiccation-resistant endospores (phylum Firmicutes, order Clostridiales). The extremophile genera Deinococcus (phylum Deinococcus-Thermus) and Hymenobacter (phylum, Bacteroidetes), rare in vertebrate gut microbiotas, accounted for 9.1% of 2.7 million sequences (CSS normalized and log2 transformed). Five bacterial genera known to exhibit strong keratinolytic capacities in vitro (Bacillus, Enterococcus, Pseudomonas, Staphylococcus, and Streptomyces) were less abundant (totaling 4%) in vulture plumage. Conclusions Bacterial rank-abundance profiles from melanized vulture plumage have no known analog in the integumentary systems of terrestrial vertebrates. The prominence of UV-resistant extremophiles suggests that solar irradiation may play a significant role in the assembly of vulture plumage microbiotas. Our results highlight the need for controlled in vivo experiments to test the effects of UV on microbial communities of avian plumage.

The ornamental plant Lagerstroemia indica (Crapemyrtle) was introduced to American gardens before 1796, but little is known about its use as a food resource by avian species. Local wintering populations of Spinus tristis (American Goldfinch), Junco hyemalis (Dark-eyed Junco), and Haemorhous mexicanus (House Finch) feed heavily on Crapemyrtle seeds, and I observed 5 additional bird species occasionally extracting seeds from dehiscent capsules in Fairfax County, VA. Planted and naturalized Crapemyrtle may be an important food resource for finches and sparrows in southeastern US.

The first isotopic baseline is established for the snail Neohelix from the Big Santeetlah Creek watershed (Appalachian Mountains). Shell δ18O (− 3.6 to + 0.4‰) declined with altitude 0.06‰ per 100 m and correlated with measured rain δ18O. A flux balance model suggests that relative humidity increased from ~ 0.89 at 710 m to ~ 0.91 at 1620 m, in agreement with higher precipitation at higher altitudes. Coherent relationships between shell, precipitation and humidity suggest that this taxon should be a valid paleoprecipitation archive in North America. The respective δ13C and δ15N values of body (− 28.3 to − 23.2‰; + 0.4 to + 4.9‰) and shell organics (− 28.2 to − 24.0‰; + 0.0 to + 3.4‰) did not exhibit a trend with altitude and were uncorrelated with potential food resources. A stable isotope-mixing model suggests that Neohelix primarily consume fungi (~ 48%) and lichen (~ 17%), with minimal ingestion of C3 plants. The relative contributions of different food items, however, varied in an unpredictable fashion along the altitudinal gradient. This study illustrates that even though snail foraging ecology from woodlands is complex and more variable than anticipated, combining several isotope systems permits dietary inferences more easily than field observations alone.

Resumen Los buitres del Nuevo Mundo (Cathartidae) estan expuestos de manera cronica a bacterias patogenas debido a su dieta carronera. Se ha hipotetizado que la fuerte acidez gastrointestinal actua como un filtro robusto que reduce significativamente la diversidad bacteriana en el alimento a medida que progresa a lo largo del aparato digestivo. Sin embargo, no existen datos publicados sobre el pH gastrointestinal de los buitres de este clado monofiletico. En este estudio, presento las primeras mediciones postprandiales (despues de la alimentacion) del pH gastrointestinal para Coragyps atratus (n = 13 individuos), Cathartes burrovianus (n = 5) y Cathartes aura (n = 2). La variacion en el pH estomacal observado (2.0–5.6) probablemente estuvo relacionada con el llenado estomacal, la dilucion concomitante de los jugos gastricos por la ingesta de carrona y el tiempo desde la ultima alimentacion. Los valores circumneutrales observados en el intestino delgado (pH 5.6–7.3) y el intestino grueso (pH 5.9–7.3) de lo...

This paper reports the first record of a territorial Limnothlypis swainsonii (Swainson's Warbler) associated with the invasive Reynoutria japonica (Japanese Knotweed). The observation adds to a growing body of literature documenting rapid behavioral adaptation to novel habitats in this globally rare warbler.

Background Current knowledge about seasonal variation in the gut microbiota of vertebrates is limited to a few studies based on mammalian fecal samples. Seasonal changes in the microbiotas of functionally distinct gut regions remain unexplored. We investigated seasonal variation (summer versus winter) and regionalization of the microbiotas of the crop, ventriculus, duodenum, cecum, and colon of the greater sage-grouse (Centrocercus urophasianus), an avian folivore specialized on the toxic foliage of sagebrush (Artemesia spp.) in western North America. Results We sequenced the V4 region of the 16S rRNA gene on an Illumina MiSeq and obtained 6,639,051 sequences with a median of 50,232 per sample. These sequences were assigned to 457 bacterial and 4 archaeal OTUs. Firmicutes (53.0%), Bacteroidetes (15.2%), Actinobacteria (10.7%), and Proteobacteria (10.1%)were the most abundant and diverse phyla. Microbial composition and richness showed significant differences among gut regions and between summer and winter. Gut region explained almost an order of magnitude more variance in our dataset than did season or the gut region × season interaction. The effect of season was uneven among gut regions. Microbiotas of the crop and cecum showed the greatest seasonal differences. Conclusions Our data suggest that seasonal differences in gut microbiota reflect seasonal variation in the microbial communities associated with food and water. Strong differentiation and uneven seasonal changes in the composition and richness of the microbiota among functionally distinct gut regions demonstrate the necessity of wider anatomical sampling for studies of composition and dynamics of the gut microbiota. Electronic supplementary material The online version of this article (10.1186/s42523-019-0002-6) contains supplementary material, which is available to authorized users.

In Supplementary Table 1 of this Article, 23 samples (B10K-DU-029-32, B10K-DU-029-33, B10K-DU-029-36 to B10K-DU-029-44, B10K-DU- 029-46, B10K-DU-029-47, B10K-DU-029-49 to B10K-DU-029-53, B10K-DU- 029-75 to B10K-DU-029-77, B10K-DU-029-80, and B10K-DU-030-03; styled in boldface in the revised table) were assigned to the incorrect institution. Supplementary Table 1 has been amended to reflect the correct source institution for these samples, and associated data (tissue, museum ID/source specimen ID, site, state/province, latitude, longitude, date collected and sex) have been updated accordingly. The original table is provided as Supplementary Information to this Amendment, and the original Article has been corrected online.

Sexual dimorphism patterns in wing area, wing loading, and wing aspect ratio of Black Vulture (Coragyps atratus) and Turkey Vulture (Cathartes aura) are unknown but are of particular interest given the prevalence of these species in scavenging communities in the Western Hemisphere. I assessed these variables in sexed specimens from wintering populations in Nashville, Tennessee. Black Vultures exhibited higher wing loading and a lower wing aspect ratio than Turkey Vultures. Neither species exhibited significant age-related or sexual dimorphism in body weight, wing span, wing area, wing loading, or wing aspect ratio. The relatively low variance observed in the pooled sample of immatures (∼9–21 mo old) and adults suggests that definitive wing size and shape are acquired several years before individuals develop the bare rugose skin and head caruncles characteristic of adults. In a broader context, this study tentatively suggests that variance estimates for wing morphology obtained from unsexed vultur...

The most intensively studied breeding population of Limnothlypis swainsonii (Swainson's Warbler) is in the White River watershed of southeastern Arkansas. However, because vegetation sampling protocols employed at this site have been significantly different from those used elsewhere, it has been difficult for land managers to reconcile datasets across the species' range in order to construct consensus quantitative benchmarks for optimal breeding habitat in bottomland hardwoods. We used a standardized sampling protocol to compare the physiognomic and floristic characteristics of breeding territories at 2 sites in the White River watershed with comparable data from other populations in Arkansas, Mississippi, Louisiana, Florida, and Virginia. Breeding territories in the combined dataset for this rare migratory species varied substantially in successional stage, floristic diversity, hydrology, and management history. Visual screening provided by understory thickets of saplings, vine tangles, and shru...

Fieldwork in the Ozark Mountains of the central United States by GRG over the last decade involving the American smoketree, Cotinus obovatus Raf. (Anacardiaceae), has resulted in the discovery of a previously unknown moth species belonging to the genus Cameraria (Lepidoptera: Gracillariidae). The larva of this species mines the leaf mesophyll of this tree, creating serpentine mines most visible from the upper (adaxial) surface of the leaf. The most closely related species to Cameraria cotinivora, n. sp. is Cameraria guttifinitella (Clemens), a common leafminer of poison ivy, Toxicodendron radicans (L.) Kuntze (Anacardiaceae). Illustrations of both species are provided as well as a COI analysis of their genetic relationship.

The naked heads of Cathartes vultures are widely believed to be adaptations for temperature regulation and to reduce plumage fouling during carrion feeding. Bright head color and the elaborate pattern of caruncles on the head and neck skin have a likely function in intra- and interspecific signaling. These integumentary characters have been difficult to study because of extensive postmortem color fading and shrinkage in museum specimens. Here I provide the first detailed description of head color and caruncles of the Greater Yellow-headed Vulture (C. melambrotus) from freshly collected specimens and provide comparative notes on sympatric populations of the Turkey Vulture (C. aura) and Lesser Yellow-headed Vulture (C. burrovianus) from Guyana.

Although the breeding ranges of Archilochus alexandri (Black-chinned Hummingbird) and Archilochus colubris (Ruby-throated Hummingbird) are narrowly parapatric in central Texas and central and southern Oklahoma, there have been few reports of hybridization in the literature and no well-documented hybrid specimens. Here we provide a comprehensive assessment of two male hybrids collected, respectively, in Grayson County, Texas, and East Baton Rouge Parish, Louisiana. As has been the pattern in other hummingbird hybrids, both specimens exhibit a blended mosaic of plumage characters of the parental species. Sequence for mitochondrial cytochrome c oxidase subunit 1 (CO1) for the hybrid specimen from East Baton Rouge Parish (LSU 182,831) confirms A. colubris as the female parent.

Understanding how ecological communities are organized and how they change through time is critical to predicting the effects of climate change. Recent work documenting the co-occurrence structure of modern communities found that most significant species pairs co-occur less frequently than would be expected by chance. However, little is known about how co-occurrence structure changes through time. Here we evaluate changes in plant and animal community organization over geological time by quantifying the co-occurrence structure of 359,896 unique taxon pairs in 80 assemblages spanning the past 300 million years. Co-occurrences of most taxon pairs were statistically random, but a significant fraction were spatially aggregated or segregated. Aggregated pairs dominated from the Carboniferous period (307 million years ago) to the early Holocene epoch (11,700 years before present), when there was a pronounced shift to more segregated pairs, a trend that continues in modern assemblages. The shift began during the Holocene and coincided with increasing human population size and the spread of agriculture in North America. Before the shift, an average of 64% of significant pairs were aggregated; after the shift, the average dropped to 37%. The organization of modern and late Holocene plant and animal assemblages differs fundamentally from that of assemblages over the past 300 million years that predate the large-scale impacts of humans. Our results suggest that the rules governing the assembly of communities have recently been changed by human activity.

Ecologists and biogeographers usually rely on a single phylogenetic tree to study evolutionary processes that affect macroecological patterns. This approach ignores the fact that each phylogenetic tree is a hypothesis about the evolutionary history of a clade, and cannot be directly observed in nature. Also, trees often leave out many extant species, or include missing species as polytomies because of a lack of information on the relationship among taxa. Still, researchers usually do not quantify the effects of phylogenetic uncertainty in ecological analyses. We propose here a novel analytical strategy to maximize the use of incomplete phylogenetic information, while simultaneously accounting for several sources of phylogenetic uncertainty that may distort statistical inferences about evolutionary processes. We illustrate the approach using a clade-wide analysis of the hummingbirds, evaluating how different sources of uncertainty affect several phylogenetic comparative analyses of trait evolution and biogeographic patterns. Although no statistical approximation can fully substitute for a complete and robust phylogeny, the method we describe and illustrate enables researchers to broaden the number of clades for which studies informed by evolutionary relationships are possible, while allowing the estimation and control of statistical error that arises from phylogenetic uncertainty. Software tools to carry out the necessary computations are offered.

The endemic hummingbirds Trochilus polytmus and T. scitulus hybridize in a narrow zone of secondary contact in eastern Jamaica. The cline in bill width across the hybrid zone represents the steepest morphological gradient documented thus far in avian biology. Hindlimb size and skeletal proxies for core body size, however, exhibit incongruent patterns of variation across the same transect. Significant correlation between bill width and skull width indicates that genetic loci that affect bill width have pleiotropic effects on cranial morphology posterior of the craniofacial hinge. This study is the first direct examination of skeletal size variation across an avian hybrid zone.

The turkey vulture (Cathartes aura) is a widespread, scavenging species in the Western Hemisphere that locates carrion by smell. Scent guided foraging is associated with an expansion of the olfactory bulbs of the brain in vertebrates, but no such neuroanatomical data exists for vultures. We provide the first measurements of turkey vulture brains, including the size of their olfactory bulbs and numbers of mitral cells, which provide the primary output of the olfactory bulbs. Comparative analyses show that the turkey vulture has olfactory bulbs that are 4× larger and contain twice as many mitral cells as those of the sympatric black vulture (Coragyps atratus), despite having brains that are 20% smaller. The turkey vulture has the largest olfactory bulbs in absolute terms and adjusted for brain size among birds, but the number of mitral cells is proportional to the size of their olfactory bulbs. The combination of large olfactory bulbs, high mitral cell counts and a greatly enlarged nasal cavity likely reflects a highly sensitive olfactory system. We suggest that this sensitive sense of smell allowed the turkey vulture to colonize biomes that are suboptimal for scavenging birds and become the most widespread vulture species in the world.

BackgroundVultures have adapted the remarkable ability to feed on carcasses that may contain microorganisms that would be pathogenic to most other animals. The holobiont concept suggests that the genetic basis of such adaptation may not only lie within their genomes, but additionally in their associated microbes. To explore this, we generated shotgun DNA sequencing datasets of the facial and gut microbiomes from the black and turkey vultures. We characterizedi) the functional potential and taxonomic diversity of their microbiomes,ii) the potential pathogenic challenges they face, and iii) elements in the microbiome that could play a protective role to the vulture’s face and gut.ResultsWe found elements involved in diseases, such as periodontitis and pneumonia (more abundant in the face), and gas gangrene and food poisoning (more abundant in the gut). Interestingly, we found taxa and functions with potential for playing health beneficial roles, such as antilisterial bacteria in the gut, and genes for the production of antiparasites and antiinsectisides in the face. Based on the identified phages, we suggest that phages aid in the control, and possibly elimination as in phage therapy, of microbes reported as pathogenic to a variety of species. Interestingly, we also identifiedAdineta vagain the gut, an invertebrate that feeds on dead bacteria and protozoans, suggesting a defensive predatory mechanism. Finally, we suggest a colonization resistance role though biofilm formation played byFusobacteriaandClostridiain the gut.ConclusionsOur results highlight the importance of complementing genomic analyses with metagenomics in order to obtain a clearer understanding of the host-microbial alliance and show the importance of microbiome-mediated health protection for adaptation to extreme diets, such as scavenging.

To determine whether stable isotopes can be used for identifying the geographic origins of migratory bird populations, we examined the isotopic composition of hydrogen (deuterium, δD), carbon (δ13C), and strontium (δ87Sr) in tissues of a migratory passerine, the black-throated blue warbler (Dendroica caerulescens), throughout its breeding range in eastern North America. δD and δ13C values in feathers, which are grown in the breeding area, varied systematically along a latitudinal gradient, being highest in samples from the southern end of the species’ breeding range in Georgia and lowest in southern Canada. In addition, δD decreased from east to west across the northern part of the breeding range, from New Brunswick to Michigan. δ87Sr ratios were highest in the Appalachian Mountains, and decreased towards the west. These patterns are consistent with geographical variation in the isotopic composition of the natural environment, i.e., with that of precipitation, plants, and soils for δD, δ13C, and δ87Sr, respectively. Preliminary analyses of the δD and δ13C composition of feathers collected from warblers in their Caribbean winter grounds indicate that these individuals were mostly from northern breeding populations. Furthermore, variances in isotope ratios in samples from local areas in winter tended to be larger than those in summer, suggesting that individuals from different breeding localities may mix in winter habitats. These isotope markers, therefore, have the potential for locating the breeding origins of migratory species on their winter areas, for quantifying the degree of mixing of breeding populations on migratory and wintering sites, and for documenting other aspects of the population structure migratory animals – information needed for studies of year-round ecology of these species as well as for their conservation. Combining information from several stable isotopes will help to increase the resolution for determining the geographic origins of individuals in such highly vagile populations.

International audience; To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.

SummarySwainson’s WarblerLimnothlypis swainsoniiis a secretive species of high conservation concern with an estimated global breeding population of 90,000 individuals sparsely distributed across 15 states in the south-eastern United States. Its status as one of the rarest songbirds in North America has been attributed to the scarcity of breeding and wintering habitat. Although the warbler was once thought to be a habitat specialist of lowland canebrakes, it is now known to breed in a wide spectrum of broadleaf forest habitats linked by the common denominator of high stem densities and visual screening in the understorey stratum. Scattered instances of a fundamental habitat expansion into early seral stages of even-aged pine plantations were first observed in east Texas in 1992. Here I report that the colonisation of pine plantations is not only locally extensive in Texas but that it is widespread on the coastal plain eastward to south-eastern Virginia. During two decades of field surveys, breeding territories (n =297) were documented in young pine plantations in 95 counties and parishes in 10 states. Occupied plantations were mostly 6–12 m tall (median = 7.5 m), corresponding to 8–15 years after planting. Soil type and the presence of interspersed broadleaf vegetation may be important co-factors in plantation occupancy. The chronology of this breeding niche expansion is poorly known but it appears to have occurred after the 1970s, most likely catalysed by the rapid growth of pine plantation silviculture after World War II. As late as 2001, it was believed that > 90% of the breeding population occurred in broadleaf floodplain forest. The recent range-wide colonisation of pine plantations changes the calculus. If the current trend continues, forest lands managed for short-rotation pine plantations will support the majority of breeding populations by the end of the 21stcentury.

Sphyrapicus varius (Yellow-bellied Sapsucker) has been reported drilling sap wells in more than 250 species of trees and woody vines in eastern North America. Criteria for species selection and use of geographically restricted endemics are poorly understood. Here I report drilling frequencies in Cotinus obovatus (American Smoketree), a rare endemic whose center of abundance occurs in the wintering range of Yellow-bellied Sapsuckers in the Ozark Mountains. Horizontal bands of sap wells were present on 4.5% of specimens (DBH ≥ 7 cm; n = 402) and 12.1% of larger-diameter classes (DBH ≥ 20 cm; n = 149). Sapsuckers preferred larger trees exhibiting little cambial dieback. Latticed arrays of sap wells similar to those observed on breeding territories were present on several large specimens. This survey indicates that the Yellow-bellied Sapsucker exploits rare species that may only be encountered on their winter territories. Documentation of a yearling inspecting a preexisting array of sap wells suggests that yearlings may obtain cues for appropriate tree species selection by examining sapsucker drillings encountered on wintering grounds. Because sap wells persist for years, cultural transmission of sapping information is likely transgenerational.

Heat-stressed New World vultures (Cathartidae) practice urohidrosis by excreting urate-rich urine on their tarsi and feet to decrease body temperature through evaporative cooling. Soft par...

Vultures are highly reliant on their sensory systems for the rapid detection and localization of carrion before other scavengers can exploit the resource. In this study, we compared eye morphology and retinal topography in two species of New World vultures (Cathartidae), turkey vultures (Cathartes aura), with a highly developed olfactory sense, and black vultures (Coragyps atratus), with a less developed sense of olfaction. We found that eye size relative to body mass was the same in both species, but that black vultures have larger corneas relative to eye size than turkey vultures. However, the overall retinal topography, the total number of cells in the retinal ganglion cell layer, peak and average cell densities, cell soma area frequency distributions, and the theoretical peak anatomical spatial resolving power were the same in both species. This suggests that the visual systems of these two species are similar and that vision plays an equally important role in the biology of both species, despite the apparently greater reliance on olfaction for finding carrion in turkey vultures.

SummaryThe endemic Jamaican subspecies of the Golden SwallowTachycineta euchrysea euchryseahas been rare and locally distributed since its discovery in 1847. By the 1950s, its geographic range had contracted to a small region along the northern frontier of Cockpit Country. The last unequivocal sight records occurred in the early 1980s, raising strong concern about the swallow’s conservation status. I conducted an island-wide search for the swallow from 1994 through 2012. Standardised censuses of aerial insectivores at 1,281 sites, including the last redoubts of the Golden Swallow in Trelawny Parish, revealed no evidence of the species. These surveys and the absence of documented sight records during the past three decades suggest that the Jamaican race of the Golden Swallow is close to extinction if not already extinct. The cause of the population decline is unknown but is most likely linked to chronic predation by introduced mammalian predators, particularly the arboreal black ratRattus rattus.

Next-Generation Biogeography In 1876, Alfred Russel Wallace mapped the zoogeographical regions of the world, based on the distributions and taxonomic relationships of broadly defined mammalian families. Wallace's classification of zoogeographical regions became a cornerstone of modern biogeography and a reference for a wide variety of biological disciplines, including global biodiversity and conservation sciences. Holt et al. (p. 74 , published online 20 December) present a next-generation map of wallacean zoogeographic regions, incorporating phylogenetic data on >20,000 vertebrate species to discern and characterize their natural biogeographic patterns.

Summary The regal moth (Citheronia regalis F.; Lepidoptera: Saturniidae) is reported for the first time feeding on foliage of the American smoketree (Cotinus obovatus Raf.; Anacardiaceae), an endemic tree with a relictual distribution on calcareous soils in the southern United States. This record constitutes the third lepidopteran species known to feed on this rare tree in a natural setting.

Assessing species survival status is an essential component of conservation programs. We devised a new statistical method for estimating the probability of species persistence from the temporal sequence of collection dates of museum specimens. To complement this approach, we developed quantitative stopping rules for terminating the search for missing or allegedly extinct species. These stopping rules are based on survey data for counts of co-occurring species that are encountered in the search for a target species. We illustrate both these methods with a case study of the Ivory-billed Woodpecker (Campephilus principalis), long assumed to have become extinct in the United States in the 1950s, but reportedly rediscovered in 2004. We analyzed the temporal pattern of the collection dates of 239 geo-referenced museum specimens collected throughout the southeastern United States from 1853 to 1932 and estimated the probability of persistence in 2011 as

Aim Deciphering the complex colonization history of island archipelagos is greatly facilitated by comprehensive phylogenies. In this study we investigate the phylogeny and biogeography of the insular reed-warblers (genus Acrocephalus) of the tropical Pacific Ocean, from Australia to eastern Polynesia. Location Oceania. Methods We used sequences of mitochondrial DNA (cytochrome b, ND2 and ATP8 genes) to infer the colonization patterns of reed-warblers endemic to Pacific islands and Australia. We sampled all known taxa of Acrocephalus in the Pacific except A. luscinius nijoi, for which no sample was available. Most taxa were represented by toe-pad samples from museum specimens collected in the 19th and 20th centuries. With a few exceptions, several specimens per taxon were sequenced independently in two institutions (Smithsonian Institution and Natural History Museum of Geneva). Results Our data indicate that Pacific reed-warblers do not form a monophyletic group, because A. luscinius luscinius from Guam falls outside the main Pacific radiation. The remaining Pacific taxa are divided into two clades: one clade includes all the reed-warblers from Micronesia (except Guam) and Australia, and two Polynesian taxa from the Line Islands and the southern Marquesas; the other clade includes all remaining Polynesian taxa. The taxa endemic to three archipelagos (Mariana, Marquesas and Society islands) are polyphyletic, suggesting several independent colonizations. Main conclusions Our results provide evidence for a complex pattern of colonization of the Pacific by reed-warblers. Calibration analyses suggest that reed-warbler lineages are much younger than the ages of the islands they occupy. Several remote archipelagos were colonized independently more than once. Consequently, we infer that the colonization of reed-warblers in the Pacific did not follow a regular, stepping-stone-like pattern. The phylogeny also suggests a previously undetected case of reverse colonization (from island to continent) for the Australian lineage and indicates that A. luscinius, as currently defined, is not monophyletic. We discuss the supertramp strategy of reed-warblers in the Pacific and show that, although Pacific reed-warblers meet some of the supertramp criteria in their aptitude for colonizing remote archipelagos, their life history characteristics do not fit the model.

Trochilus maria Gosse, 1849, was described from a specimen obtained by Richard Hill from the “mountains of Manchester,” most likely the Don Figueroa Mountains in Manchester Parish, Jamaica (Rapkin, 1851). Gosse (1849a: 258) quoted field notes from Hill stating that the specimen “was startled from a nest in which were two young ones, and was obtained by charging some of the blossoms of the mountain-pride (Spathelia simplex) on which it was feeding, with minute doses of strychnine. As soon as it sucked from one of the poisoned chalices, it fluttered, and fell dead.” Gosse (1849a: 258) provided a detailed plumage description (see below) and summarized, “It is near to Polytmus, but differs from it in the inferior length of its beak, and in the colours of the plumage; but being apparently young, it is impossible to say what the adult condition may prove. I am happy however to fortify my own judgment by that of Mr. Gould, who on my showing it to him decidedly pronounced it new.”

The Eskimo Curlew (Numenius borealis), now near extinction, was intensively hunted during fall migration along the Atlantic coast from Labrador to Long Island through the late 19th century. Scores of post-1850 records from this region have been gleaned from the literature but the rate of population decline has never been assessed. George H. MacKay's shooting journal, which has been largely overlooked, includes quantitative data on curlew abundance trends from 1875 to 1897 on Nantucket Island, Massachusetts. MacKay observed 650 curlews and his party bagged 87 during 231 hunting days logged during the flight period (21 August–2 October) over 22 hunting seasons. The last major flights were observed in 1881. Although he continued to hunt enthusiastically through the early 1890s, annual totals of curlews observed by MacKay declined significantly (rs, = 0.40, p < 0.05) from 1875 to 1897, as did annual bag totals (rs = -0.41, p < 0.05). Annual bag totals of American Golden Plovers (Pluvialis dominica),...

Hydrogen isotope analysis of feather keratin (δ2HF) has become an essential tool for tracking movements between breeding and wintering populations of migratory birds. In particular, δ2HF has been used to create δ2HF isoscapes that can be used to assign the geographic origins of molt. The majority of past studies have sampled a portion of a single feather as an isotopic proxy for the entire plumage although surprisingly little is known about variation of stable isotopes within and between feather tracts of individuals in local populations. Here we examine δ2HF variation in 24 pterylographic variables (9 primaries, 6 secondaries, 6 rectrices, and 3 patches of ventral contour feathers) in individual specimens of black-throated blue warbler (Setophaga caerulescens) breeding in the Big Santeetlah Creek watershed (5350 ha), southern Appalachian Mountains. By restricting our study to territorial ASY males (after second year) inhabiting a small watershed, we could focus on δ2HF variation generated during the complete prebasic annual molt in a circumscribed population while factoring out age and sexual differences in foraging behavior, isotopic incorporation, and post-breeding dispersal. Summed within-individual variation (δ2HF) across 24 pterylographic variables ranged from 12 to 60‰ (= 21.8 ± 9.4‰), with 81% of the individuals exhibiting variation ≥ 16‰ (reproducibility of analyses was ≤ 4 ‰). Adjacent feathers in feather tracts tend to have more similar δ2HF values than feathers grown weeks apart, consistent with the stepwise replacement of flight feathers. The pooled population sample exhibited significant δ2HF variation in primaries (-78 to -21‰), secondaries (-80 to -17‰), rectrices (-78 to -23‰), and ventral contour feathers (-92 to -32‰). Strong year effects in δ2HF variation were observed in each of the 24 pterylographic variables. Altitudinal effects were observed only in ventral contour feathers. The current findings demonstrate that within-individual variation (δ2HF) may be much greater than previously thought in migratory species that molt on or near breeding territories. Our study also highlights the need for greater pterylographic precision in research design of isotope-based studies of avian movement. Within-individual and within-population δ2HF variation should be incorporated in geographic assignment models. In a broader context, the staggered Staffelmauser pattern of molt in wood warblers provides an exceptional view of the seasonal variation of hydrogen isotopes circulating in blood plasma during the six-week period of annual molt.

The role of intraspecific and interspecific interactions in structuring biotic communities at fine spatial scales is well documented, but the signature of species interactions at coarser spatial scales is unclear. We present evidence that species interactions may be a significant factor in mediating the regional assembly of the Danish avifauna. Because >95% of breeding species ( n = 197) are migratory, we hypothesized that dispersal limitation would not be important and that breeding distributions would largely reflect resource availability and autecological habitat preferences. Instead, we detected a striking pattern of spatial segregation between ecologically similar species at two spatial scales with a suite of null models that factored in the spatial distribution of habitats in Denmark as well as population size and biomass of each species. Habitat utilization analyses indicated that community-wide patterns of spatial segregation could not be attributed to the patchy distribution of habitat or to gross differences in habitat utilization among ecologically similar species. We hypothesize that, when habitat patch size is limited, conspecific attraction in concert with interspecific territoriality may result in spatially segregated distributions of ecologically similar species at larger spatial scales. In the Danish avifauna, the effects of species interactions on community assembly appear pervasive and can be discerned at grain sizes up to four orders of magnitude larger than those of individual territories. These results suggest that species interactions should be incorporated into species distribution modeling algorithms designed to predict species occupancy patterns based on environmental variables.

A BSTRACT.— Analyses of body size evolution in hummingbirds (Trochilidae) are hampered by the lack of standardized weight data for most of the ~330 described species. Moreover, little is known of the morphological correlates of body weight upon which a body-size index could be constructed. I investigated the skeletal correlates of body weight in the endemic Black-billed Streamertail ( Trochilus scitulus ) of Jamaica. Mist-netted males were weighed at initial capture and after the holding period (2.1–6.7 hr). Seven of 10 skeletal characters exhibited marginally higher correlations with the second measure of body weight, which was unbiased by gut contents. Sternum length emerged as the single best skeletal predictor of body weight. A multivariate index (PCA 1) derived from three sternal characters had approximately the same predictive value as a comparable analysis of all ten skeletal characters. This suggests that a simple multivariate measure of sternal morphology may provide a reliable body size index for hummingbirds. K EYWORDS.— B ody size index , hummingbirds , museum specimens , Trochilidae , Trochilus scitulus.

— We investigated the genetic population structure of the Black-throated Blue Warbler (Dendroica caerulescens), a Nearctic-Neotropic migrant passerine that breeds in cool mixed deciduous-coniferous forests in eastern North America. A cline in plumage color in breeding populations in the central Appalachian Mountains suggests either a contact zone between two formerly allopatric populations or the presence of a strong contemporary selection gradient. Analysis of 333 base pairs of the mitochondrial control region from 287 individuals sampled from 14 populations revealed relatively high haplotype diversity, low nucleotide diversity, and limited but significant phylogeographic structure across the breeding range (analysis of molecular variance [AMOVA], variation among populations = 2.7%; P < 0.01) and between northern and southern population groups (AMOVA, variation among groups = 2.9%; P < 0.01). Genetic differentiation among populations did not conform to an isolation-by-distance model. Nucleotide ...

We isolated and characterized 15 microsatellite loci from the endemic Jamaican streamertail hummingbird Trochilus polytmus. Loci were screened in 12 individuals of both T. polytmus and its sister species T. scitulus, also a Jamaican endemic. The number of alleles per locus ranged from 2 to 10, observed heterozygosity ranged from 0 to 1, and the probability of identity values ranged from 0.038 to 0.663. These new loci provide tools for characterizing the narrow hybrid zone between the two species.

A hummingbird specimen from Ramsey Canyon, Huachuca Mountains, southeastern Arizona, represents a hybrid of Lampornis clemenciae (Blue-throated Hummingbird) × Calypte anna (Anna's Hummingbird). The specimen, which constitutes the only verified instance of hybridization between a species in the “mountain gem” group of hummingbirds and a species in the “bee” group, exhibits a blended mosaic of plumage characters of the parental species.

A hummingbird specimen collected by W. W. Brown in 1917 in the Huachuca Mountains, southeastern Arizona, is a hybrid of Hylocharis leucotis (white-eared hummingbird) × Selasphorus platycercus (broad-tailed hummingbird). Brown's specimen, which exhibits a blended mosaic of plumage characters of the presumed parental species, represents the first known instance of hybridization between species currently placed in Hylocharis and Selasphorus.

Nature Communications 5: Article number: 5498 (2014); Published: 25 November 2014; Updated: 21 October 2015. The original version of this Article contained an error in the spelling of the author Thomas Sicheritz-Ponten, which was incorrectly given as Thomas Sicheritz Ponten. This has now been corrected in both the PDF and HTML versions of the Article.

The unique hummingbird specimen collected by J. W. Sefton, Jr., in 1932 in the Rincon Mountains, southeastern Arizona, is confirmed to be a hybrid, Calypte costae × Selasphorus platycercus. The hybrid exhibits a blended mosaic of plumage characters of the parental species. Other parental hypotheses were ruled out on the basis of plumage color and on measurements of the outermost rectrix (R5).