Coragyps Research Articles

Ectoparasites of Coragyps atratus (Bechstein, 1793) (Accipitriformes: Cathartidae) on Bucaramanga, Santander, Colombia

To identify and to list ectoparasite species of black vulture in two locations in Bucaramanga, Colombia. Scope. To contribute to the knowledge of ectoparasites species found in black vultures in the metropolitan area of Bucaramanga, at the northeastern Andes. Methodology. The birds were captured in Guarin Marketplace and "El Carrasco" Solid Waste Disposal Center, both in the metropolitan area of Bucaramanga, Colombia. To obtain the ectoparasites, each black vulture were introduced into a fumigation chamber previously modified to preserve the life of the bird during the procedure. Moreover, some feathers were taken and preserved in ethanol 70%. Main results. In total, 1,696 ectoparasites were collected from 18 black vultures (Coragyps atratus) in two localities of Bucaramanga (Colombia). The parasites were identified as Cathartacarus coragyps (Gabuciniidae), Dermanysus gallinae (Dermanyssidae), Cuculiphilus alternatus (Menoponidae), Falcolipeurus marginalis (Philopteridae), Laemobothrion glutinans (Laemobothriidae) and Olfesia bisulcata (Hippoboscidae). The most abundant species were Cuculiphilus alternatus with 1,217 specimens and Cathartacarus coragyps with 295. Conclusions. Most of these records are new to the region and contribute to improving the knowledge concerning the ectoparasites distribution in the study area. Mann-Whitney tests and the calculated parasitological indexes show differences between the two sampling places.

Effects of climate change and human influence in the distribution and range overlap between two widely distributed avian scavengers

SummaryClimate change can cause geographic displacement of the ecological niche of a species, so that similar species that previously did not coexist could begin to face new interactions. Such geographic displacement and increased competition can also be exacerbated by anthropic intervention. Until less than 100 years ago,Vultur gryphusandCoragyps atratusdid not coexist. Nowadays, possibly as a result of climate change, changes in the distributions of both species created areas where they are now sympatric. Through ecological niche modeling, we evaluated the possible effects that future scenarios of climate change and human influence would have on the distribution and sympatry between the two species. Our models predict that the current distribution ofV. gryphuswill be reduced between 18% and 24% by 2050 and between 21% and 32% by 2070. Additionally, they predict that the distribution ofC. atratuswill be reduced by 31–52% by the year 2050 and 15–60% by 2070. The two algorithms predict a reduction in the areas of sympatry. However, for the northern Andes the overlap between the two species will increase, reaching up to 70% in the year 2070. The distribution ofC. atratuswill move towards higher areas in the altitudinal gradient, and this will generate an increase in the current sympatry between both species. No clear trend was observed on the effect of human influences on the areas of overlap between the scenarios evaluated. The possible effects of climate change and anthropic intervention in future scenarios found in this study highlight the need to include these effects in future analyses and conservation programs ofV. gryphusand other threatened vultures.

The Irvingtonian Avifauna of Cumberland Bone Cave, Maryland.

The early and mid-Pleistocene avian communities of North America are best known from the Rocky Mountain region and peninsular Florida. In the Appalachian Mountain region, only a small number of avian bones from mid-latitude cave deposits have been attributed to this time period. Here, I enlarge this record by reporting on bird bones from Cumberland Bone Cave in western Maryland, a well-known locality for large and small Irvingtonian mammals and other vertebrates. The taxa identified encompass ground birds, waterfowl, a hawk, two eagles, a vulture, an owl, a jay, a flycatcher, a junco or sparrow, and a finch. No purely boreal elements are confirmed as part of the avian assemblage, and all of the extant species that are positively or tentatively identified in the assemblage still occur in the region today. An immature bone referred to the Black Vulture (Coragyps atratus (Bechstein)) represents an Irvingtonian breeding record for the species in Maryland. This record occurs at the northern limit of the current breeding range for the genus. Extinct species in the assemblage include the Passenger Pigeon (Ectopistes migratorius (Linnaeus)), a large screech owl (Megascops guildayi (Brodkorb Mourer-Chauviré 1984)), and the large goose, Branta dickeyi Miller 1924. It can be argued that none of these represent the extinction of a phyletic lineage during the Irvingtonian. Based on the broad habitat preferences of modern counterparts of the birds in the assemblage, we can expect that Irvingtonian habitats near the site included mixed forest with mast-producing hardwoods and both early and later successional stages represented. There must have been fluvial, wetland, or lacustrine habitat suitable for waterbirds nearby, and probably also open woodland or grassy savannah areas, suitable for vulture foraging, turkey nesting, and booming by Ruffed Grouse.

Feeding Ecology Drives Lead Exposure of Facultative and Obligate Avian Scavengers in the Eastern United States

Lead poisoning of scavenging birds is a global issue. However, the drivers of lead exposure of avian scavengers have been understood from the perspective of individual species, not cross-taxa assemblages. We analyzed blood (n = 285) and liver (n = 226) lead concentrations of 5 facultative (American crows [Corvus brachyrhynchos], bald eagles [Haliaeetus leucocephalus], golden eagles [Aquila chrysaetos], red-shouldered hawks [Buteo lineatus], and red-tailed hawks [Buteo jamaicensis]) and 2 obligate (black vultures [Coragyps atratus] and turkey vultures [Cathartes aura] avian scavenger species to identify lead exposure patterns. Species and age were significant (α < 0.05) predictors of blood lead exposure of facultative scavengers; species, but not age, was a significant predictor of their liver lead exposure. We detected temporal variations in lead concentrations of facultative scavengers (blood: median = 4.41 µg/dL in spring and summer vs 13.08 µg/dL in autumn and winter; p = <0.001; liver: 0.32 ppm in spring and summer vs median = 4.25 ppm in autumn and winter; p = <0.001). At the species level, we detected between-period differences in blood lead concentrations of bald eagles (p = 0.01) and red-shouldered hawks during the winter (p = 0.001). During summer, obligate scavengers had higher liver lead concentrations than did facultative scavengers (median = 1.76 ppm vs 0.22 ppm; p = <0.001). These data suggest that the feeding ecology of avian scavengers is a determinant of the degree to which they are lead exposed, and they highlight the importance of dietary and behavioral variation in determining lead exposure. Environ Toxicol Chem 2020;39:882-892. © 2020 SETAC.

Geographical variation and current knowledge on breeding traits of vultures in the neotropics

New World vultures (Cathartidae) have essential roles in ecosystem functioning, but are susceptible to increasing anthropogenic impacts. Knowledge of several breeding, behavioral, and distributional parameters of Neotropical vultures is poorly organized and have not been properly reviewed. Here, we made a comprehensive review of original breeding records from museums, literature, and citizen science (WikiAves) for each of the six species of vultures occurring in the Neotropical region. These data were used to review breeding patterns and geographical distribution, and identify information gaps. The 567 records of breeding from the Neotropics assembled are very biased, mostly for Black Vulture Coragyps atratus (n = 319) and Turkey Vulture Cathartes aura (n = 166), and unevenly distributed among regions and subspecies. The four other species still have a great lack of knowledge about their breeding in the wild (Lesser Yellow-headed Vulture Cathartes burrovianus (n = 20), Greater Yellow-headed Vulture C. melambrotus (n = 2), King Vulture Sarcoramphus papa (n = 21), and Andean Condor Vultur gryphus (n = 30)). We show for the first time that Neotropical Cathartidae have convergent breeding seasons among sympatric taxa, delay start of breeding with increasing latitude, and have an allometric relationship between adult size and egg size. Nevertheless, larger samples of breeding data, especially from some regions and taxa, such as the two “Yellow-headed Vulture” species, are still needed. We also show that breeding traits could be helpful for preventive management and conservation strategies involving both expanding and decreasing populations of vultures in the Neotropics.

Riqueza y abundancia de rapaces diurnas del Cañón de Fernández, Lerdo, Durango

El monitoreo biológico es esencial para comprender la dinámica poblacional, los procesos ecológicos y los problemas emergentes. En este estudio determinamos la riqueza y abundancia de las rapaces diurnas en el Parque Estatal Cañón de Fernández en Durango, México. Detectamos 11 especies, cinco de éstas están bajo alguna categoría de riesgo según la Norma Oficial Mexicana 059-2010: gavilán pecho canela (Accipiter striatus), gavilán de cooper (A. cooperii), aguililla negra menor (Buteogallus anthracinus), aguililla rojinegra (Parabuteo unicinctus) y aguililla pecho rojo (Buteo lineatus). Las especies más abundantes fueron Coragyps atratus, Cathartes aura y Buteo jamaicensis. El hábitat donde obtuvimos más registros fue el bosque de galería. Las rapaces del área ven amenazada su conservación por la pérdida de hábitat, cacería y electrocución.

Comparison of lead contamination among related scavenging birds sharing food sources: a call for caution when using surrogate species

Lead contamination is a global problem affecting a large number of bird species around the world. Among the different avian guilds, vultures and facultative scavengers are particularly threatened by this toxic metal. However, little information is available about differences in exposure to this metal for sympatric vulture species that share food resources. We compared blood lead concentrations of two closely related sympatric obligate scavenger species, the abundant Black Vulture Coragyps atratus and the threatened Andean Condor Vultur gryphus in north‐western Patagonia, Argentina. We sampled 28 Andean Condors and 29 Black Vultures trapped foraging in the same area in the steppe. We also sampled 16 Black Vultures foraging in a rubbish dump to determine whether there were differences in lead contamination among foraging sites. Andean Condors had significantly higher mean blood lead concentrations than Black Vultures. There was no difference in lead concentrations between Black Vultures trapped in the steppe and in the rubbish dump. The prevalence and probability of lead concentrations above the threshold level (20 µg/dL) was higher for Andean Condors than for Black Vultures, potentially producing different effects on their health. This disparity in lead contamination may be due to differences in their foraging habits or in their susceptibility to this toxic metal. Overall, our results suggest caution in using an abundant surrogate species to infer lead contamination in a closely related but harder to sample species.

Exposure of Raptors in Central Argentina to St. Louis Encephalitis and West Nile Viruses

Arthropod-borne viruses represent the most important emerging viruses worldwide. Saint Louis encephalitis (SLEV) and West Nile (WNV) viruses are vectored by Culex spp. mosquitoes and amplified by several bird species. We carried out an extensive retrospective serosurvey study to analyze the exposure of free-ranging raptors to SLEV and WNV in central Argentina. We collected samples from eight species of raptors between 2008 and 2015. We used Plaque Reduction Neutralization Tests (PRNT) to analyze 523 plasma samples for both viruses. Of the individuals tested for WNV, 85.2% of the Swainson's Hawks (Buteo swainsoni) were positive. Fewer birds presented neutralizing antibodies against SLEV: 20.8% of the Black Vultures (Coragyps atratus), 25% of the Southern Caracaras (Caracara plancus), and 0.3% of the American Kestrels (Falco sparverius). One Swainson's Hawk was positive for both viruses. We found no neutralizing antibodies in samples from Turkey Vultures (Cathartes aura), Chimango Caracaras (Phalcoboenus chimango), Burrowing Owls (Athene cunicularia), and a Ferruginous Pygmy-Owl (Glaucidium brasilianum). Although seroprevalence varied among species, our results confirmed SLEV and WNV circulation in resident and migratory populations of raptors in central Argentina. These findings suggest the need for further studies regarding circulation and ecological characterization of these viruses in bird communities in Argentina.

The Status of Vultures Neophron Percnopterus, Gypaetus Barbatus, Gyps Fulvus, Aegypius Monachus (Accipitriformes) in Azerbaijan

The inventory of vultures was conducted in 2004–2016. Modern areal and nesting places of Griffon vulture (Gyps fulvus), Black vulture (Aegypius monachus), Egyptian vulture, (Neophron percnopterus) and Bearded vulture (Gypaetus barbatus) in Azerbaijan was determined. Our results reveals that 60.6% (n=20) of nesting locations were found in Lesser Caucasus, 36.3% (n=12) in Great Caucasus, 3.0% (n=1) in Talysh mountains. Over the last 13 years the total known population of these species decreased by 15.3%. Primary reason of this decline is the abandonment of livestock farms and graze lands, accompanied by the expansion of cultivated areas (P = 0.0001) since large domestic ruminants are important source of food for Griffon vultures,. The other important threats to these species were identified as nestling removal, capture and trade of wild birds for exhibiting them in zoological gardens and roadside restaurants, destructing the nests of Black vultures, ecotourism and recreation has impacted on the decrease in the number of Griffon vultures (P =0.0001). In 2016, 61 pairs of Griffon vulture, 59 pairs of Egyptian vulture, 16 pairs of Black vulture, 9 pairs of Bearded vulture were recorded in the territories of Azerbaijan.

Arthropod fauna associated with black vulture and turkey vulture nests (Accipitriformes: Cathartidae) in south-Central Kentucky, USA

Arthropods were collected from seven black vulture and two turkey vulture nests in South-Central Kentucky. Species diversity in each nest ranged from a low of two to 10 species in total. Three nest cavities that had the highest amount of heterogeneous organic matter concomitantly had the highest number of arthropod taxa. Insects were the most abundant arthropods and included taxa from the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera and Psocoptera. Diptera and Coleoptera were represented by the highest number of families (and species), with seven (ten spp.) and four (eight spp.), respectively. Discovered Acari included eight species in seven families, of which four were members of the Mesostigmata. A majority of the insects collected were either scavengers or accidentals and do not have a strong link with the nest habitat. But taxa associated with guano or feathers for food sources or those that are predacious on fly eggs or larvae appear to have a loose association with these vulture nests.

Evidence of niche differentiation for two sympatric vulture species in the Southeastern United States

BackgroundAs obligate scavengers utilizing similar habitats, interspecific competition undoubtedly occurs between resident black (Coragyps atratus) and turkey (Cathartes aura) vultures. In the interest of exploring how sympatric species coexist through habitat segregation, we examined resource selection of resident black and turkey vultures in the southeastern United States (US) for evidence of niche differentiation.MethodsUsing fine-scale movement data, we assessed interspecific seasonal differences in monthly roost reuse frequency and roost site fidelity, as well as monthly flight, roost, and diurnal rest site resource selection based on > 2.8 million locations of 9 black vultures and 9 turkey vultures tracked from September 2013 to August 2015 using Groupe Spécial Mobile/Global Positioning System (GSM/GPS) transmitters.ResultsBlack vultures generally exhibited greater roost fidelity as well as a greater maximum number of nights spent at a single roost than turkey vultures. Patterns of flight, roost, and resting habitat selection within the home range varied monthly as well as between species, providing evidence for habitat segregation and niche differentiation by sympatric vultures. In particular, our results indicate the importance of wooded wetlands for resting and roosting locations for both species, and revealed clear differences in the use of forested habitats between species during flight, resting, and roosting behavioral states.ConclusionsBy examining differences in resource selection and spatial ecology of black and turkey vultures across a range of behaviors, this study demonstrates mechanisms of niche differentiation in these ecologically similar species, and enhances potential for conservation and informed management of this important group of birds.

Functional analysis and treatment of self-injurious feather plucking in a black vulture (Coragyps atratus).

The etiology and maintenance of self-injurious feather plucking (FP) have been attributed to biological and environmental processes, yet a definitive solution has not been found. The current study investigated the application of a functional analysis and function-based treatment to reduce the FP of a black vulture (Coragyps atratus). FP was found to be maintained by positive reinforcement in the form of contingent attention. A treatment consisting of noncontingent reinforcement decreased FP, and levels of FP remained low during schedule thinning. The current study further demonstrates the validity of function-based assessment and treatment with captive animals.

Evaluation of allometric scaling as a tool for extrapolation of the enrofloxacin dose in American black vultures (Coragyps atratus).

To determine the pharmacokinetics of enrofloxacin after IV administration in American black vultures (Coragyps atratus), to compare clearance of enrofloxacin in American black vultures with clearance of this fluoroquinolone in other avian species, and to evaluate whether allometric scaling is an appropriate tool for dose extrapolation in avian species. 6 healthy adult American black vultures. Enrofloxacin concentrations were quantified by use of high-performance liquid chromatography. Pharmacokinetics of enrofloxacin was determined in American black vultures after IV administration. Pharmacokinetic parameters for 12 avian species obtained from 24 pharmacokinetic studies were used. Allometric analysis of enrofloxacin pharmacokinetic parameters was performed. Volume of distribution at steady state for enrofloxacin was 3.47 L/kg, clearance was 0.147 L/h·kg, and elimination half-life was 18.3 hours. Comparisons among avian species revealed that American black vultures had the lowest extraction ratio for enrofloxacin (1.04%). Only the volume of distribution at steady state and clearance had a good allometric fit. Goodness of fit was improved when ratites were not included in the analysis. Results suggested that the use of allometric scaling for the prediction of volume of distribution at steady state could provide a suitable method for extrapolation of enrofloxacin doses among avian species; however, allometric scaling could not be used to adequately predict the clearance of enrofloxacin.

A mathematical model to describe the demographic dynamics of long-lived raptor species

Population viability analysis of threatened large and long-lived raptor species has strong limitations due to the restricted demographic information available for these species. In this work, we mathematically model the demographic dynamics of these raptor species through time-indexed branching processes. By assuming the more general non-parametric statistical setting, we determine accurate estimates for the most relevant reproductive parameters involved in the model. To this end, we propose an algorithm based on approximate Bayesian computations methods. As illustration, by using real data of counts of the number of pairs in the population, we apply the proposed statistical and computational methods to describe the demographic dynamics of the Eurasian black vulture colony located at National Park of Monfragüe (Spain), which appears to be both the largest and densest breeding colony worldwide. In the scenario of these data-poor species, the class of time-indexed branching processes introduced appears to be appropriate and a more cost-effective method to evaluate dynamics and viability of the populations, applicable to the conservation of these taxa.

Using multiple data sources to investigate foraging niche partitioning in sympatric obligate avian scavengers

AbstractAs carrion feeders competing for a limited and ephemeral resource, avian scavengers are ideal model organisms to study mechanisms of niche partitioning. Previous work has focused on observations of species’ interactions at carcasses, and although fruitful, the inclusion of behavior beyond that at carcasses, such as movement patterns, could yield a more comprehensive understanding of mechanisms of foraging niche partitioning. Our goal was to assess how differences in physiological, morphological, and social characteristics between sympatric black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) manifest interspecific variation in movement patterns, foraging habitats, and carcass use to reduce direct competition. Both species are obligate scavengers that co‐occur across much of the New World. Turkey vultures are solitary foragers with enhanced olfactory capabilities and wings optimized for energy‐efficient low‐altitude soaring. Black vultures are aggressive, heavier bodied, and forage socially. We assessed interspecific variation in carcass exploitation using experimental carcass trials encompassing a range of habitats, carcass sizes, and seasons, and used GPS telemetry to compare how soaring conditions influenced daily space use and diurnal patterns of movement activity for each species. Turkey vultures occurred more often at small (i.e., rabbit) carcasses, and those obscured by forest cover than black vultures, and were the first vultures recorded at 94% of carcasses visited by both species. Both species increased movement rates and daily ranges when soaring conditions were favorable; however, turkey vultures had higher travel rates regardless of soaring conditions. Our results suggest the olfactory sense of turkey vultures allows them to locate smaller and visually obscured carcasses more efficiently than black vultures, facilitated by wing morphology that allows them to forage over large areas efficiently. Socially foraging black vultures appear specialized at locating larger carcasses in open habitats, which does not require as much foraging flight as turkey vultures. Our study illustrates how inclusion of movement ecology into niche partitioning studies provides a more complete understanding of the mechanisms of coexistence in avian scavenger guilds. This approach may provide important information to guide conservation efforts, such as supplemental feeding, of imperiled vulture species.

Scavenger birds exploiting rubbish dumps: Pathogens at the gates.

Different bacteria are present in rubbish dumps used as food resources by various bird species. Birds may be good indicators of the presence of zoonotic diseases in these sites since they can be infected with zoonotic pathogens by foraging on organic waste, and can also act as carriers. We studied if foraging in rubbish dumps increases the occurrence of Salmonella spp. and Chlamydia psittaci in American black vultures (Coragyps atratus, hereafter black vultures) from northwest Patagonia. We compared these pathogens isolated from or detected in cloacae and oropharynx swabs in two different groups of black vultures: individuals trapped in (a) the Patagonian wild steppe and (b) in a rubbish dump. We found that black vultures are colonized by Salmonella spp. (particularly Salmonella enterica serotypes Typhi, Paratyphi A, Salmonella enterica subsp.arizonae) and Chlamydia psittaci. Interestingly, there were differences in the prevalence of Salmonella spp., especially Salmonella Typhi, between individuals foraging in the rubbish dump and the steppe, but not in the prevalence of Chlamydia psittaci. The pathogens isolated from black vultures may impact their health status but could also have health impacts in other bird species and even humans. In fact, Salmonella Typhi can cause severe disease in humans leading to death. Our results are globally relevant given that bacterial infections from rubbish dumps may affect different species exploiting these sites around the world. There is a need to better control pathogens in rubbish dumps to avoid the risk of infecting wildlife, which could act as potential dispersers and reservoirs of these pathogens.

Allowable take of black vultures in the eastern United States

ABSTRACTBlack vultures (Coragyps atratus) have been increasing in density and expanding their range in the eastern United States since at least the 1960s. In many areas, their densities have increased to the level where they are causing damage to property and livestock and the number of requests for allowable take permits has increased throughout these areas. The United States Fish and Wildlife Service (USFWS) requires updated information to help inform the number of take permits that could reduce conflicts while meeting obligations under the Migratory Bird Treaty Act. We expanded analyses used to estimate allowable take in Virginia to cover the range of black vultures in the eastern United States. We used the prescribed take level approach, which integrates demographic rates, population size estimates, and management objectives into an estimate of allowable take. We provide estimates of allowable take at 4 different scales: individual states, Bird Conservation Regions, USFWS administrative regions, and flyways. Our updated population time series provides evidence of rapidly increasing black vulture populations in many regions of the eastern United States, with an overall population estimate of approximately 4.26 million in 2015 in the Atlantic and Mississippi Flyways. Estimated allowable take ranged from a few hundred individuals per year in states at the northern end of the species range to approximately 287,000/year over the entire eastern United States. The USFWS has no legal mandate regarding the spatial scale at which take should be managed and we found little biological evidence of subpopulation structure for black vultures in the eastern United States. We suggest that allowable take for the species be implemented at a scale that meets stakeholder objectives (e.g., reducing conflict, and ensuring that black vultures are not extirpated from local areas) and is efficient for administrative and monitoring purposes. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

ECOLOGÍA URBANA DE AVES: RELACIÓN DE LAS PLANTAS, CLIMA Y RUIDO CON LA BIODIVERSIDAD DE AVES EN LA CIUDAD DE IQUITOS, PERÚ

La ecología urbana brinda directrices a las políticas de desarrollo urbano, para que las sociedades humanas vivan en ambientes más saludables y naturales. Las aves son buenas indicadoras de los ecosistemas naturales, por tal razón con el objetivo de determinar la relación de las plantas, clima y ruido con la biodiversidad de aves urbanas de la ciudad de Iquitos (Perú), se utilizó el método de conteo por puntos en seis de las principales plazas de la ciudad. El diseño de muestreo en cada plaza consistió de cuatro puntos de observación, y se colectó información durante tres días consecutivos, desde las 6:00 a 9:00 h y 16:00 a 18:00 h. La riqueza de aves fue de 50 especies, con mayor abundancia de Columba livia, Coragyps atratus y Tyrannus savana, y la riqueza de plantas fue de 19 especies, con dominancia de Adonidia merrillii, Elaeis oleifera, Livistona chinensis y Ficus benjamina. La temperatura ambiental entre las plazas no difieren, pero si la temperatura del suelo, humedad relativa y ruido. Hay relación del índice de abundancia de aves carnívoras con la riqueza de especies de plantas en general, plantas nativas y riqueza de árboles. La presencia de plantas, sobre todo de árboles altos proporcionaría mayor oferta de alimento, sitios de perchado y de nidificación a las especies de aves carnívoras. A mayor número de estas especies de aves en un ambiente urbano mayor será el avance hacia una ciudad verde.

Quantification of avian hazards to military aircraft and implications for wildlife management.

Collisions between birds and military aircraft are common and can have catastrophic effects. Knowledge of relative wildlife hazards to aircraft (the likelihood of aircraft damage when a species is struck) is needed before estimating wildlife strike risk (combined frequency and severity component) at military airfields. Despite annual reviews of wildlife strike trends with civil aviation since the 1990s, little is known about wildlife strike trends for military aircraft. We hypothesized that species relative hazard scores would correlate positively with aircraft type and avian body mass. Only strike records identified to species that occurred within the U.S. (n = 36,979) and involved United States Navy or United States Air Force aircraft were used to calculate relative hazard scores. The most hazardous species to military aircraft was the snow goose (Anser caerulescens), followed by the common loon (Gavia immer), and a tie between Canada goose (Branta canadensis) and black vulture (Coragyps atratus). We found an association between avian body mass and relative hazard score (r2 = 0.76) for all military airframes. In general, relative hazard scores per species were higher for military than civil airframes. An important consideration is that hazard scores can vary depending on aircraft type. We found that avian body mass affected the probability of damage differentially per airframe. In the development of an airfield wildlife management plan, and absent estimates of species strike risk, airport wildlife biologists should prioritize management of species with high relative hazard scores.

Protective role of the vulture facial skin and gut microbiomes aid adaptation to scavenging

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 skin and large intestine microbiomes of the black vulture (Coragyps atratus) and the turkey vulture (Cathartes aura). We characterized the functional potential and taxonomic diversity of their microbiomes, the potential pathogenic challenges confronted by vultures, and the microbial taxa and genes that could play a protective role on the facial skin and in the gut.ResultsWe found microbial taxa and genes involved in diseases, such as dermatitis and pneumonia (more abundant on the facial skin), and gas gangrene and food poisoning (more abundant in the gut). Interestingly, we found taxa and functions with potential for playing beneficial roles, such as antilisterial bacteria in the gut, and genes for the production of antiparasitics and insecticides on the facial skin. 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 identified Adineta vaga in the gut, an invertebrate that feeds on dead bacteria and protozoans, suggesting a defensive predatory mechanism. Finally, we suggest a colonization resistance role through biofilm formation played by Fusobacteria and Clostridia in 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.