Gary R. Graves

Smithsonian Institution · Department of Vertebrate Zoology

Despite evidence of declining biosphere integrity, we currently lack understanding of how the functional diversity associated with changes in abundance among ecological communities has varied over time and before widespread human disturbances. We combine morphological, ecological, and life-history trait data for >260 extant bird species with genomi...

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...

Studies of animal movement and migration over large geospatial scales have long relied on natural continental-scale hydrogen isotope (δ 2 H) gradients in precipitation, yet the physiological processes that govern incorporation of δ 2 H from precipitation into plant and then herbivore tissues remain poorly understood, especially at the molecular lev...

Recent renewed interest in using fossil data to understand how biotic interactions have shaped the evolution of life is challenging the widely held assumption that long-term climate changes are the primary drivers of biodiversity change. New approaches go beyond traditional richness and co-occurrence studies to explicitly model biotic interactions...

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...

The causes of continental patterns in species richness continue to spur heated discussion. Hypotheses based on ambient energy have dominated the debate, but are increasingly being challenged by hypotheses that model richness as the overlap of species ranges, ultimately controlled by continental range dynamics of individual species. At the heart of...

Diet and host phylogeny drive the taxonomic and functional contents of the gut microbiome in mammals, yet it is unknown whether these patterns hold across all vertebrate lineages. Here, we assessed gut microbiomes from ∼900 vertebrate species, including 315 mammals and 491 birds, assessing contributions of diet, phylogeny, and physiology to structu...

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 chal...

Large mammals are at disproportionately high risk of extinction globally, and the ecological impacts of their loss will last beyond our lifetimes. Research shows that the end-Pleistocene mass extinction of large mammals left a significant ecological legacy, from shifting vegetation and fire regimes to changes in nutrient cycling and biogeochemistry...

Hydrogen isotope analysis of feather keratin (δ 2 H F

Summary statistics for δ2HF values for primaries (P1-P9). (PDF)

Summary statistics for δ2HF values for secondaries (S1-S6). (PDF)

Summary statistics for δ2HF values for ventral contour feathers (V1-V3). (PDF)

Pearson correlation coefficients for δ2HF values for pairwise combinations of secondaries (S1-S6). (PDF)

Pearson correlation coefficients for δ2HF values for pairwise combinations of primaries (P1-P9). (PDF)

Pearson correlation coefficients for δ2HF values for pairwise combinations of rectrices (R1-R6). (PDF)

Summary statistics for δ2HF values for rectrices (R1-R6). (PDF)

Pearson correlation coefficients for δ2HF values for pairwise combinations of ventral contour feathers (V1-V3). (PDF)

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, i...

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 popula...

Background Vultures 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 shot...

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...

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 acr...

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 ass...

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 difficu...

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 th...

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...

Vultures are scavengers that fill a key ecosystem niche, in which they have evolved a remarkable tolerance to bacterial toxins in decaying meat. Here we report the first deep metagenomic analysis of the vulture microbiome. Through face and gut comparisons of 50 vultures representing two species, we demonstrate a remarkably conserved low diversity o...

Swainson's Warbler Limnothlypis swainsonii is 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 win...

Comparing inferences among datasets generated using short read sequencing may provide insight into the concerted impacts of divergence, gene flow and selection across organisms, but comparisons are complicated by biases introduced during dataset assembly. Sequence similarity thresholds allow the de novo assembly of short reads into clusters of alle...

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 patter...

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 specie...

I observed black-crowned night-herons (Nycticorax nycticorax) swimming and kleptoparasitizing American coots (Fulica americana) at an artificial lake in Pinal County, Arizona. This appears to be the first record of interspecific kleptoparasitism by a swimming ardeid.

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 divergen...

Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific...

Vultures are scavengers that fill a key ecosystem niche, in which they have evolved a remarkable tolerance to bacterial toxins in decaying meat. Here we report the first deep metagenomic analysis of the vulture microbiome. Through face and gut comparisons of 50 vultures representing two species, we demonstrate a remarkably conserved low diversity o...

Scaled Ground Cuckoo Neomorphus squamiger Todd, 1925, is a rare and poorly known taxon from Pará and Amazonas, Brazil. Most taxonomic authorities have treated it as a subspecies of Rufous-vented Ground Cuckoo N. geoffroyi owing to plumage similarities and distribution. The aim of this study was to review the taxonomic status of N. squamiger in the...

Scaled Ground Cuckoo Neomorphus squamiger Todd, 1925, is a rare and poorly known taxon from Pará and Amazonas, Brazil. Most taxonomic authorities have treated it as a subspecies of Rufous-vented Ground Cuckoo N. geoffroyi owing to plumage similarities and distribution. The aim of this study was to review the taxonomic status of N. squamiger in the...

Environmental conditions, dispersal lags, and interactions among species are major factors structuring communities through time and across space. Ecologists have emphasized the importance of biotic interactions in determining local patterns of species association. In contrast, abiotic limits, dispersal limitation, and historical factors have common...

Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific...

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...

We report the first records of tree-nesting Chaentra pelagica (Chimney Swifts) in Arkansas from the White River National Wildlife Refuge (WRNWR). These represent the only well-documented reports of tree-nesting swifts for many decades in the lower Mississippi Valley. The WRNWR may support a large population of tree-nesting swifts.

Kreft and Jetz’s critique of our recent update of Wallace’s zoogeographical regions disregards the extensive sensitivity analyses we undertook, which demonstrate the robustness of our results to the choice of phylogenetic data and clustering algorithm. Their suggested distinction between “transition zones” and biogeographic regions is worthy of fur...

The endemic Jamaican subspecies of the Golden Swallow Tachycineta euchrysea euchrysea has 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 co...

Corrigendum Corrigendum to ''Next-generation sequencing reveals phylogeographic structure and a species tree for recent bird divergences'' After publication, two errors came to our attention regarding the methods for generating the digest fragments prior to next-generation sequencing. In Table 1, the primer sequence for the second listed EcoRI adap...

Modern attempts to produce biogeographic maps focus on the distribution of species, and the maps are typically drawn without phylogenetic considerations. Here, we generate a global map of zoogeographic regions by combining data on the distributions and phylogenetic relationships of 21,037 species of amphibians, birds, and mammals. We identify 20 di...

The largest irruptive migration of the Great Gray Owl (Strix nebulosa Forster, 1772) recorded since 1831 occurred in Minnesota, USA, during the winter of 2004–2005. We tested the hypothesis that morphometric indicators of nutritional stress covary with stable isotope signatures in a sample of 265 owls killed by vehicle collisions. The ratio of carb...

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##Assembly-Data-START## Assembly Method :: Sequencher v. 4.8 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: Sequencher v. 4.8 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

The Division of Birds, National Museum of Natural History, Smithsonian Institution in Washington, DC, has obtained and released DNA barcodes for 2808 frozen tissue samples. Of the 1,403 species represented by these samples, 1,147 species have not been barcoded previously. This data release increases the number of bird species with standard barcodes...

Next generation sequencing (NGS) technologies are revolutionizing many biological disciplines but have been slow to take root in phylogeography. This is partly due to the difficulty of using NGS to sequence orthologous DNA fragments for many individuals at low cost. We explore cases of recent divergence in four phylogenetically diverse avian system...

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.

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 missi...

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 obtaine...

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'...

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. Bec...

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 Bl...

I investigated the physiognomic and floristic characteristics of Swainson's Warbler (Limnothlypis swainsonii) territories at five localities within its core breeding range in Arkansas, Mississippi, Louisiana, and Florida. The warbler attained its greatest abundance (10–20 territorial males/km2) in floodplain forest characterized by small (<25 cm db...

Understanding the causes of spatial variation in species richness is a major research focus of biogeography and macroecology. Gridded environmental data and species richness maps have been used in increasingly sophisticated curve-fitting analyses, but these methods have not brought us much closer to a mechanistic understanding of the patterns. Duri...

We used mtDNA sequence data to confirm that the controversial 100-year-old holotype of the Bogotá sunangel (Heliangelus zusii) represents a valid species. We demonstrate that H. zusii is genetically well differentiated from taxa previously hypothesized to have given rise to the specimen via hybridization. Phylogenetic analyses place H. zusii as sis...

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 pro...

We analyzed carbon isotope ratios (delta13C) of liver and pectoral muscle of Black-throated Blue Warblers (Dendroica caerulescens) to provide a mesoscale perspective on altitudinal tenancy in the Appalachian Mountains, North Carolina, U.S.A. Movements of males are poorly understood, particularly the degree to which yearlings (first breeding season)...

Background: Geographic ranges, randomly located within a bounded geographical domain, produce a central hump of species richness (the mid-domain effect, MDE). The hump arises from geometric constraints on the location of ranges, especially larger ones. Questions: (1) How do patterns of species richness in one-and two-dimensional MDE models change a...

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 t...

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 o...

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 kno...

Due to extensive clearing of bottomland forest in the southeastern United States, Swainson's Warbler (Limnothlypis swainsonii) is restricted in many drainages to seasonally inundated buffer zones bordering rivers and swamps. This migratory species is especially vulnerable to flooding because of its ground foraging ecology, but little is known about...

Las aves paserinas son frecuentemente empleadas como modelos en estudios sobre competencia espermática y paternidad extra-pareja, pero la cronología intraespecífica de la maduración testicular y sus consecuencias empíricas y teóricas sobre los sistemas de apareamiento de las aves han sido en buena parte ignoradas. En este estudio analicé la variaci...