Coragyps Research Articles

Миграция хищных птиц через Западный Кавказ в осенний период

Миграция хищных птиц через Западный Кавказ в осенний период

Antipoisoning activities in Bulgaria to enforce raptors conservation in the country

The first antipoisoning dog unit in Bulgaria was founded in 2016. The dog unit operated more than 4 years (October 2016 – December 2020) in the frame of the Conservation of Black and Griffon Vultures in the cross border Rhodope Mountains (LIFE 14 NAT/NL/901) project. During that time, 153 searches and patrols were conducted. The majority of the patrols were executed in the Eastern Rhodopes (80%), which is the core area of the vulture populations in Bulgaria. The total number of all findings is 310, with 40 of them being illegally poisoned animals, 7 were animal remains, and 10 were poisoned baits. The average number of victims found per poisoning incident is 2.86±3.5. The anti-poisoning dog unit found 11 poisoned animal species. Vultures comprised 17.5% (n=7) of all victims found. In all these cases vultures were unintentional victims as the main cause of poison use were human-predator and human-human conflicts. Wolves and domestic dogs were the most common victims comprising 22.5% and 20% respectively of all poisoned animals found. Carbofuran and Methomyl were identified as the main poison substances used in the investigated cases. Along with the dog unit operation, a development of a National action plan to combat the illegal use of poisons in the wild (hereafter NAP) was initiated with national authorities and NGOs (Ministry of Environment and Waters, Bulgarian Food Safety Agency, Executive Forestry Agency, National Police, Bulgarian Academy of Sciences, other NGOs). In 2021, after intensive communication with the Ministry of Environment and waters, the plan was finally endorsed by the Minister. Local Network of Stakeholders against Wildlife Poisoning in Bulgaria was created in the last two years (2021–2022) in Bulgaria. It includes 55 livestock breeders, farmers, hunters, veterinarians, and mayors of villages.

Смертность хищных птиц в Северо-Западном Раджастане, Индия (2017–2022 годы)

A major contributing factor in declining populations of vultures is believed to be the widespread use of drugs such as Diclofenac, once commonly-used as a livestock anti-inflammatory drug. Use of Diclofenac is now banned in India. However, during the last 3 years, vulture’s death cases are increasing not only in Rajasthan but also in other parts of India. From 2017–2022, a total of 791 vultures of 3 species i.e. Eurasian Griffon Vulture (Gyps fulvus), Cinereous Black Vulture (Aegypius monachus), and Egyptian Vulture (Neophron percnopterus) and 231 Steppe Eagles (Aquila nipalensis) were found dead at Jorbeer dumping site. Jorbeer has been declared as conserved forest area, but dead livestock dumping site is not part of the protected area. The dramatic vulture decline observed across India leads to the emergence of a range of new ecological threats by influencing the numbers and distribution of other scavenging species. Increased feral dog populations have been reported all over in India, posing many associated disease risks, such as rabies, to humans and wildlife. India already has a very high incidence of rabies, and a severe shortage of quality rabies vaccine in rural areas could further aggravate the problem. Similarly, increased crow populations at carcass dumps in vicinity of settlements pose a risk of infections to poultry, domesticated birds, avian & humans. The situation has improved slightly after the ban on diclofenac (veterinary and human use) in India since 2015, but other drugs used to treat livestock continue to kill migratory raptors and vultures in northern India. The main drugs involved into this are Ketoprofen and Phenylbutazone. The existence of only a small proportion (<0.8%) of ungulate carcasses containing lethal levels of such drugs is sufficient to cause a rapid decline in vulture populations. Strategic planning is needed to protect migratory vultures and eagles from Russia, Kazakhstan and Central Asian countries. While the number of vultures is declining day by day, the death toll in Rajasthan is a major part of the world percentage.

Биоценотические связи сайгаков с крупными хищными птицами

Conservation of biodiversity has recently become the most urgent task due to global anthropogenic transformation of the environment. Therefore, more and more attention is being paid to the role of species in biogeocenosis, their biocoenotic relationships, and the assessment of ongoing changes. Due to the unprecedented growth of the Ural Saiga (Saiga tatarica) population, the study of ecology, behavior, and biocenotic relationships as factors affecting the structure of the ecosystem and, in particular, large birds of prey has become increasingly important. The saiga population in West Kazakhstan Region in 2023 is estimated at 1.13 million individuals, which is highly concentrated in Zhanibek (8,200 km2), Bokeyordinsky (19,214 km2), and Kaztalovsky (18,600 km2) districts of the region. And here we should pay attention to the fact that with anthropogenic changes in the habitat (construction of roads, canals, gas and oil pipelines, etc.), macroevolutionary changes in saiga behavior have begun to occur – saigas are no longer the nomadic species they were 100 years ago, they no longer nomade over great distances, and are becoming more sedentary. Our observations show that saigas do not travel more than 100 km and stay mainly around sors (dried up salt lakes). The next fact is that from late November to early December, saigas start their rut. As a result of extreme exhaustion during the rut, up to 96% of males die. The huge biomass accumulates in a relatively small area. This cannot cause the population of predators and scavengers to grow. The growth of predatory mammals is limited by the availability of accessible drinking water, so we did not observe an increase in the population of wolves, but the number of jackals and steppe cats increased. The growth of jackals is possible not only due to the availability of food in the autumnwinter period, but also due to increased hunting pressure in neighboring areas of the Russian Federation. The growth of the steppe cat (which is most abundant in the Bokeyordinsky district) may be due to the growth of saigas, as it has been reported that saiga remains have been found in the cat's stomach. The above-mentioned districts of West Kazakhstan Region have the highest density of large birds of prey. There are both direct and indirect biocoenotic links between saigas and large birds of prey – Steppe Eagle (Aquila nipalensis), Imperial Eagle (Aquila heliaca), White-Tailed Eagle (Haliaeetus albicilla), Cinereous Vulture (Aegypius monachus), and Eurasian Griffon Vulture (Gyps fulvus). Studies, both our own and those of the Association for the Conservation of Biodiversity of Kazakhstan (ACBK), show a high density of the breeding of Steppe Eagles in West Kazakhstan Region (WKR) in areas where saigas congregate, especially in the Kaztalovsky District, while in other areas of the region their numbers are very low. Its direct and indirect biocenotic relationship with saigas can be traced here: – Direct. All the nests we examined contained saiga remains. We have never seen Steppe Eagles hunting saigas, most likely picking up fallen or sick individuals, as well as the afterbirths of saiga calves. We saw a Steppe Eagle eating a saiga (most likely it was hit by a car, as its ribs were broken), the peritoneum was opened, internal organs were lying separately, the eagle did not eat them. It mostly pecked meat from the thighs of the hind legs. The carcass was fresh, blood had not coagulated yet. In the area of Araltobe Sor on 20/08/2020 we observed a large pre-migration concentration of the Steppe Eagle of about 300 individuals. – Indirect. In areas where saigas graze there is a high number of the Little Ground Squirrel (Spermophilus pygmaeus), the main food object of the Steppe Eagle. By regulating the height of grass stands, favorable conditions for the Little Ground Squirrel are created. In other areas of the region, the Little Ground Squirrel has become rare. The White-Tailed Eagle (Haliaeetus albicilla) is abundant during winter migration in areas where saigas congregate: On November 15, 2021, we counted 43 individuals following a herd of saigas on the 100 km Kaztalovka – Khan Ordasy road route. In recent years, we have recorded annual visitations of the Black Vulture (Aegypius monachus) in the region. We attribute this to the growth of the saiga population. In 2019, we recorded an encounter of the Eurasian Griffon Vulture in the vicinity of Saihin settlement, which is the first record for the last 50 years. Analyzing all of the above, we can conclude that the growth of saiga population positively affects the dynamics of population growth of large birds of prey in the West Kazakhstan Region.

SEASONAL EFFECTS ON ROADKILL OF WILD VERTEBRATES IN A STRETCH OF A BRAZILIAN NORTHEAST FEDERAL HIGHWAY

In Brazil, roadkill of wild animals represents an important part of the local biodiversity loss. Even so, studies focused on road ecology are still very scarce for many regions of the country. The present study aimed to monitor the mortality of wild vertebrates on the Federal Highway BR-235, in Sergipe (Brazil), and analyze possible seasonal variations in roadkill rates. Between August 2020 and July 2021, two samples were taken per month in a stretch of 20 km of the BR-235, traveled by motorcycle at a speed of 40 to 50 km/h. Seventy-five individuals of 30 vertebrate species were recorded. The roadkill rate was 0.156 individuals per kilometer covered. The most recorded classes were birds with 29 individuals (13 spp.) and mammals with 23 individuals (10 spp.). The species with the highest number of records was Rhinella sp. with 16 records (21.6%), Coragyps atratus with eight records (10.8%) and Didelphis albiventris with seven records (9.4%). Among the species recorded, two are threatened with extinction ( Leopardus tigrinus and Puma yagouaroundi ). A greater number of roadkill was registered in the rainy season. The results reveal this stretch of BR-235 as a source of continuous mortality for the region's fauna.

The mechanisms of color production in black skin versus red skin on the heads of New World vultures

A determination of how the color of animal integument is produced is a starting point for investigations into the function and evolution of coloration. The mechanisms that give rise to the color of bare skin of New World vultures are largely unexplored. Here, we investigate the source of color production in the bare skin of Turkey Vultures (Cathartes aura) and Black Vultures (Coragyps atratus). Using UV–vis reflectance spectroscopy, we found evidence that hemoglobin is the primary pigment responsible for the red coloration of the bare skin on the heads of Turkey Vultures, and that eumelanin is responsible for the black coloration of the bare skin on the heads of Black Vultures. Light microscopy of incisional skin samples further supported these mechanisms of color production by revealing the presence of numerous blood vessels near the surface of the Turkey Vulture skin, and a high concentration of melanosomes in the skin of Black Vultures. Using high performance liquid chromatography (HPLC), we detected carotenoids within the skin of both species with significantly higher total concentrations of carotenoids in the skin of Turkey Vultures compared to the skin of Black Vultures. The carotenoids detected were dietary carotenoids that typically produce yellow coloration when accumulated in integument and were present in low concentrations. We hypothesize that the dietary carotenoids present do not contribute to the color of the skin, but rather help to compensate for the lack of melanosomes found in Turkey Vulture skin. The presence of additional carotenoids may act as an antioxidant to minimize UV damage when the bare Turkey Vulture head skin is exposed to direct sunlight for prolonged periods of time when soaring and scavenging for food.

Amplification of Black Vulture (Coragyps atratus) DNA from regurgitated food pellets

Estudios que dependen de colecta no invasiva de ADN de aves muchas veces utilizan heces o plumas. Algunas aves, como los zopilotes, regurgitan materia sin digerir en forma de egagrópilas que se encuentran comúnmente bajo los dormideros. Nuestra investigación muestra que las egagrópilas regurgitadas son una fuente de ADN viable y no invasiva para estudios de ecología molecular de zopilotes. Nuestros objetivos fueron amplificar 5 loci microsatelitales diseñados para distinguir aura gallipavo (Cathartes aura) y zopilote negro (Coragyps atratus) en un solo PCR múltiple así como determinar cuánto tiempo persiste el ADN nuclear blanco después de que una egagrópila de zopilote es regurgitada y expuesta al ambiente. Colectamos egagrópilas de zopilotes negros en cautiverio y las colocamos en un aviario al aire libre durante un tiempo máximo estimado de 12, 24, 36 y 48 h. Realizamos un frotis de la superficie de las egagrópilas para una extracción y amplificación del ADN de los zopilotes usando el panel de marcadores. Todos los alelos amplificados cayeron en los rangos predichos para los zopilotes negros para todos los 5 loci, lo que apoya el uso de este panel de microsatélites para identificación de especies de zopilotes. El éxito general de amplificación de muestras colectadas de muestras colectadas 0-12 h después de regurgitadas fue de 82.3%. Las egagrópilas colectadas 12–24 h, 24–36 h y de 36–48 h tuvieron solamente 12%, 10.2% y 4.5% de éxito de amplificación, respectivamente, lo que podría ser debido a un evento de lluvia. Nuestro enfoque será útil para muestreos genéticos no invasivos dirigidos a ADN nuclear. Estos resultados deberían fomentar los estudios de muestreo genético no invasivo en otras especies que regurgiten egagrópilas, como rapaces, aves acuáticas y aves playeras. Palabras clave: ADN no invasivo, ADN nuclear, éxito de amplificación, loci microsatelitales, PCR mútiple.

Regional Intravenous Anaesthesia (Bier's block) in Black-headed Vulture (Coragyps atratus) Submitted to Digit Amputation

Background: The Coragyps atratus flies long distances in search of food and has a marked behaviour of food competition. Since they are frequently found in areas of recent human occupation, they are subject to trauma, which may require surgical interventions. Locoregional blocks are used as part of a balanced-anaesthesia protocol and are currently being evaluated in birds, with brachial plexus block being the main technique described in the literature. However, to our knowledge, this is the first description of intravenous regional anaesthesia (Bier's block) in a vulture. Thus, we aim to report the use of Bier's block with 1% lidocaine, in a black-headed vulture submitted to digit amputation. Case: A black-headed vulture (Coragyps atratus), weighing 2 kg, was rescued and referred to the Veterinary Hospital due to its inability to fly. Physical examination revealed a swollen digit in the right pelvic limb. Radiographic examination confirmed the intermediate phalanx fracture of the 4th digit of the right pelvic limb with signs suggestive of advanced osteomyelitis. The animal was referred to surgery for amputation of the affected digit. Before surgery, water and food were withdrawn for 12 h. Pre-anaesthetic medication consisted of 1 mg/kg midazolam and 0.5 mg/kg morphine intramuscularly (IM). Anaesthetic induction was performed through face mask with isoflurane, followed by orotracheal intubation with a 3 mm-endotracheal tube. Anaesthesia was maintained with isoflurane through a non-rebreathing circuit in 100% oxygen. Using a multiparametric monitor, heart rate (HR), respiratory rate (RR), end-tidal CO2 (EtCO2), oxyhemoglobin saturation (SpO2), electrocardiography (ECG), systolic blood pressure (SBP) and core temperature (CT) were evaluated. Antisepsis of the right pelvic limb was performed and an elastic band was applied around the distal region of the affected tibia to serve as a tourniquet. A scalp vein set was used to access the lateral saphenous vein in the region distal to the tourniquet, and 5 mg/kg lidocaine 1% was injected intravenously. The patient remained stable during the procedure, with no need for analgesic rescue. The tourniquet was gradually released 40 min past its application, being completely removed after 45 min of surgery. The anaesthetic supply was interrupted, with extubation after 4 min; the patient had satisfactory anaesthetic recovery. Discussion: The present report describes the success in using the technique of intravenous regional anaesthesia with 1% lidocaine for digit amputation performed on a specimen of black-headed vulture. The pre-anaesthetic medication provided analgesia, satisfactory sedation for venoclysis, and anaesthetic induction without complications. Anaesthetic induction and maintenance in birds are preferably performed with inhaled anaesthetics, thus the choice of mask induction. Despite the reduction in RR soon after induction, the patient remained on spontaneous ventilation. Bier's block using 5 mg/kg lidocaine showed to be an easy and safe technique in vultures, but doses up to 6 mg/kg lidocaine are not associated with adverse effects in birds. The intravenous regional anaesthesia technique described in this manuscript promoted adequate analgesia for the digit amputation procedure in black-headed vultures and allowed hemodynamic stability without significant anaesthetic complications. Thus, the present report points to the potential use of this locoregional block in other birds. Keywords: locorregional block, lidocaine, anaesthesia. Título: Anestesia regional intravenosa (bloqueio bier) em urubu-de-cabeça-preta (Coragyps atratus) submetido à amputação de dígito. Descritores: bloqueio locorregional, lidocaína, anestesia.

Thermal circulation affects Black Vulture Coragyps atratus soaring behaviour in the vicinity of two airports in south-east Brazil.

The growth of air traffic all over the world faces an increasing risk of aircraft collisions with birds. The Black Vulture (Coragyps atratus), being a large soaring species living across the Americas, presents a serious hazard to airplanes. The reduction of this threat without harm to birds is a complex task requiring thorough investigations of their behaviour. Various natural and anthropogenic factors can affect the distribution of soaring Black Vultures in the surrounds of airports. Here we focus on the impact of meteorological parameters (i.e. air temperature, relative humidity, wind speed and atmospheric pressure) on Black Vulture flight at two study sites. In the course of one year, from September 2012 to August 2013, we surveyed with binoculars the soaring activity of Black Vultures around Amarais and Presidente Prudente airports in the southeast of Brazil. The study areas were characterized by tropical climatic conditions with mild dry winter and hot rainy summer. We found that the frequency of soaring flights depended on the wind speed, a proxy of the strength of thermals (upward air flows). This finding is consistent with habits of Black Vultures using thermals for soaring. In contrast, air temperature, air humidity and atmospheric pressure did not affect their activity. We also showed that the different seasons affected the birds’ behaviour, but the degree of their influence depended on the level of anthropogenic pressure in the soaring terrain. Two contrasting types of daily soaring activity appeared: a plateau-like trend and a tendency of two peaks at morning and afternoon with a pronounced drop between them. Our findings can be used to inform methods to reduce the risk of collisions between aircraft and Black Vultures at our study sites, and our analytical approach could be applied elsewhere.

A 14,000-year-old genome sheds light on the evolution and extinction of a Pleistocene vulture

The New World Vulture [Coragyps] occidentalis (L. Miller, 1909) is one of many species that were extinct by the end of the Pleistocene. To understand its evolutionary history we sequenced the genome of a 14,000 year old [Coragyps] occidentalis found associated with megaherbivores in the Peruvian Andes. occidentalis has been viewed as the ancestor, or possibly sister, to the extant Black Vulture Coragyps atratus, but genomic data shows occidentalis to be deeply nested within the South American clade of atratus. Coragyps atratus inhabits lowlands, but the fossil record indicates that occidentalis mostly occupied high elevations. Our results suggest that occidentalis evolved from a population of atratus in southwestern South America that colonized the High Andes 300 to 400 kya. The morphological and morphometric differences between occidentalis and atratus may thus be explained by ecological diversification following from the natural selection imposed by this new and extreme, high elevation environment. The sudden evolution of a population with significantly larger body size and different anatomical proportions than atratus thus constitutes an example of punctuated evolution.

Coragyps atratus (BECHSTEIN, 1793)

Coragyps atratus is a species of New World vulture belonging to the Cathartiformes order. Its geographical distribution comprises urban areas from the South of North America, Central America, and South America to Tierra del Fuego in Argentina. This species is increasingly adapted to live close to human concentrations, benefiting from the food supply due to the incorrect disposal of organic waste, therefore, these factors contributed to the population increase. C. atratus are common near urban areas and can lead to several problems, such as damage to urban architecture, including historic buildings. However, C. atratus provides invaluable ecosystem services, increasing the flow of nutrients through food chains and reducing the transmission of infectious diseases through carcass removal. C. atratus uses a mosaic of habitat types to build its nests, even in urban environments. We describe here an unconventional case of nesting by C. atratus in a building in an urban area in the municipality of Pelotas, Rio Grande do Sul, Brazil.

Cannibalism by Black Vultures (Coragyps atratus)

Cannibalism by Black Vultures (Coragyps atratus)

Draft Genome Sequences of Two Commensal Enterococcus faecalis Strains Isolated from American Black Vultures (Coragyps atratus) in Brazil.

ABSTRACTWe report the draft genome sequences of two commensal Enterococcus faecalis strains (designated Ca-2 and Ca-18) recovered from the cloacae of two healthy American black vultures (Coragyps atratus) in Rio de Janeiro, Brazil. The strains were found to carry a variety of antimicrobial resistance and virulence-associated genes.

The limits of olfactory perception in black vultures: a field experiment

New World vultures have been considerably studied regarding their sense of smell. Cathartes species present a remarkable development of their olfactory apparatus, and experiments conducted with the turkey vulture (Cathartes aura) demonstrated that they can locate carrion exclusively by smell at considerable distances. Black vultures (Coragyps atratus), because of their less developed olfactory apparatus, have been compared with the turkey vulture as a phylogenetically related species lacking the sense of smell. However, little evidence from behavioural studies supports the lack of olfaction of black vultures. We conducted a field experiment where we presented urban black vultures a binary choice of decaying fish and sand (serving as control) inside plastic bags. Birds chose the fish bait in 81% of the times they approached the plastic bags. The probability of reaction decreased significantly with the distance between the birds and the fish bait, being virtually null at 40–50 m away. Furthermore, birds clearly reacted more when the fish presented higher decaying time (7 compared to 2 days). These results show that olfaction is not only used by black vultures but is probably the most relevant sense when they search for food hidden in plastic bags and in piles of unsorted waste, which is the most common foraging environment for this species in urban areas where they are very abundant.

Blood Lead Concentrations of Free-Ranging North Florida Raptors: 2008-17.

Whole blood samples for lead analysis were collected from 441 raptors admitted to the Zoological Medicine Service at the University of Florida (US) between 1 January 2008 and 31 December 2017. The species included Bald Eagles (Haliaeetus leucocephalus), Ospreys (Pandion haliaetus), Black (Coragyps atratus) and Turkey (Cathartes aura) Vultures, Barred (Strix varia) and Great Horned (Bubo virginianus) Owls, and Red-tailed (Buteo jamaicensis) and Red-shouldered (Buteo lineatus) Hawks. Our hypothesis was that geography, seasonality, and hunting strategies of these species would all affect the blood lead concentrations. Blood lead concentrations were found to vary significantly between species, with known scavengers having higher values. Additionally, seasonal differences were seen between winter and summer, but the county in which these individuals were found did not alter the blood lead concentrations. We found lead contamination to be a common and considerable problem in Bald Eagles and vultures but not as evident in nocturnal and other diurnal raptors in North Florida. Furthermore, concentrations were highest during winter in this temperate location, suggesting a possible relationship with hunting seasons despite a lack of big game.

Spatial risk modeling of cattle depredation by black vultures in the midwestern United States

AbstractNegative economic impacts resulting from wildlife disrupting livestock operations through depredation of stock are a cause of human‐wildlife conflict. Management of such conflict requires identifying environmental and non‐environmental factors specific to a wildlife species' biology and ecology that influence the potential for livestock depredation to occur. Identification of such factors can improve understanding of the conditions placing livestock at risk. Black vultures (Coragyps atratus) have expanded their historical range northward into the midwestern United States. Concomitantly, an increase in concern among agricultural producers regarding potential black vulture attacks on livestock has occurred. We estimated area with greater or lesser potential for depredation of domestic cattle by black vultures across a 6‐state region in the midwestern United States using an ensemble of small models (ESM). Specifically, we identified landscape‐scale spatial factors, at a zip code resolution, associated with reported black vulture depredation on cattle in midwestern landscapes to predict future potential livestock depredation. We hypothesized that livestock depredation would be greatest in areas with intensive beef cattle production close to preferred black vulture habitat (e.g., areas with fewer old fields and early successional vegetation paired with more direct edge between older forest and agricultural lands). We predicted that the density of cattle within the county, habitat structure, and proximity to anthropogenic landscape features would be the strongest predictors of black vulture livestock‐depredation risk. Our ESM estimated the relative risk of black vulture‐cattle depredation to be between 0.154–0.631 across our entire study area. Consistent with our hypothesis, areas of greatest predicted risk of depredation correspond with locations that are favorable to vulture life‐history requirements and increased potential to encounter livestock. Our results allow wildlife managers the ability to predict where black vulture depredation of cattle is more likely to occur in the future. It is in these areas where extension and outreach efforts aimed at mitigating this conflict should be focused. Researchers and wildlife managers interested in developing or employing tools aimed at mitigating livestock‐vulture conflicts can also leverage our results to select areas where depredation is most likely to occur.

Mass mortality events and declining obligate scavengers in the Anthropocene: Social feeders may be critical

A pervasive but understudied global change is occurring in the Anthropocene. Wildlife mass mortality events (MMEs) are increasing in frequency causing the abrupt entry of unusually large amounts of carrion into ecosystems, while most vertebrate obligate scavenger species are declining. We hypothesized that behavioral plasticity could still allow obligate-vertebrate scavengers to maintain carrion recycling with increasing carrion biomass as a result of relaxed competition, and that consumption is likely to be driven by those species less behaviorally constrained. We designed an experiment by establishing plots with increasing carrion biomass. The lowest carrion biomass represented a normal level of carrion with a single carcass, with each subsequent level of carrion biomass roughly doubling until reaching a carrion density similar to a recent MME. We monitored behavior of two obligate scavenger species: a social feeder (i.e., black vulture, Coragyps atratus) and a relatively solitary feeder (i.e., turkey vulture, Cathartes aura). In support of our hypothesis, group size and number of individuals feeding increased at the highest carrion biomass level for the more social feeder, while the less social increased solely the number of individuals feeding. Likewise, activity pattern overlap between the species increased with carrion biomass likely because both spent more of the day consuming larger carrion inputs. The effects of these behavioral changes resulted in an increase in estimated consumption with carrion biomass, which was primarily driven by the more social species. Our results indicate that vulture behavioral plasticity may be critical to maintain carrion recycling services in the Anthropocene.

Trophic interactions at avian carcasses: Do scavengers feed on vulture carrion?

Scavenging is a pervasive foraging strategy among vertebrates, yet researchers have only recently begun to reveal the complex implications of scavenging dynamics. Scavenging studies have predominantly used lower trophic level (i.e., herbivore) species as carrion bait, and the few studies that have used higher trophic level (i.e., carnivore) carrion have found these carcass types are generally avoided by vertebrates or scavenged by fewer species than similarly sized herbivore carcasses. No studies have assessed the fate of carcasses of obligate scavengers. To investigate potential differences in scavenging dynamics among avian carrion representing different guilds and trophic levels, we conducted scavenging trials using 20 replicates of two obligate scavenger species (i.e. black vulture, Coragyps atratus; turkey vulture, Cathartes aura) and two lower trophic level species, chicken (Gallus gallus domesticus), and mallard (Anas platyrhynchos). Carcass trials were conducted at the Savannah River Site, SC, USA, and monitored with remote cameras. We hypothesized carcasses of vultures would persist longer and have a distinct scavenging community compared to lower trophic level carcasses (mallard and chicken). As expected, turkey and black vulture carcasses persisted in the environment longer, were less likely to be entirely consumed by vertebrate scavengers, and had a different scavenging community than mallard and chicken carcasses. These results contribute to the growing body of evidence suggesting higher trophic level carrion is exploited differently by vertebrate scavengers. Our findings suggest nutrients derived from vulture carcasses are likely largely reincorporated into lower trophic levels.

Wintering habitat modelling for conservation of Eurasian vultures in northern India

Eurasian Black Vulture (EBV) and Eurasian Griffon Vulture (EGV), while residents elsewhere, winter in Uttar Pradesh, India. Knowledge of the habitat and regulating factors is obligatory for protection and better management of these vultures. Therefore, different types of habitats were mapped using eight species distribution models. Presence records from field survey, published data and citizen science, and 23 bioenvironmental raster layers were the model inputs. Eighteen models were developed whose strength varied greatly. As per the performance indicators, GBM and GLM were found to be superior models for EGV. For EBV all models were acceptable. MARS, with good model strength, was rejected on the grounds of field verification. However, the Ensemble model, overall, was found the best. As per this model, good habitat was restricted mostly in the Tarai ecozone. The top two vital variables were NDVI, and bio13 for both the vultures. The most vital temperature variable for EGV was bio08 while bio09 for EBV. Tarai ecozone showed the largest expanse of suitable area for both the vultures followed by Vindhyan-Bundelkhand, Gangetic plains and Semi-arid ecozones. Among the two, EBV (49000 km2) had more suitable area than EGV (37000 km2). Agricultural areas were found to be largely unsuitable. As per land cover, good habitat was mostly confined in forests. For better management of these wintering vultures which need only roosting and foraging, it is proposed that destruction of forested habitat and decrease in foraging materials needed immediate attention and control.

Diets of Black Vultures and Turkey Vultures in Coastal South Carolina, USA with a Review of Species' Dietary Information

Food availability resulting from anthropogenic land-use changes may have contributed to the recent increase of Cathartes aura (Turkey Vulture) and Coragyps atratus (Black Vulture) populations. We assessed anthropogenic contributions to diets of these species by analyzing 176 pellets collected from communal roosts in coastal South Carolina. To provide further insight into diets, we conducted a literature review of pellet-based studies for both species. Our pellet analyses demonstrated consumption of 12 mammal species with Odocoileus virginianus (White-tailed Deer) as the primary food item, present in 65% of samples and constituting 35% average percent volume in pellets. Mephitis mephitis (Striped Skunk) and Procyon lotor (Raccoon) were also commonly consumed. Presence of anthropogenic items in 47% of pellets indicated substantial garbage consumption. Our review consisted of 14 studies and revealed wide variability in diet across study sites, with large mammals (>15 kg) typically comprising the majority of species consumed. We suggest that increasing deer populations provide an important source of carrion for vultures in this area and likely throughout eastern North America. Ungulate populations, roadkill, and garbage appear to contribute considerably to Turkey Vulture and Black Vulture diets. As such, mitigation of human–vulture conflict will require effective garbage and roadkill management as Turkey Vulture and Black Vulture populations increasingly expand.