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Scavenging is critical for nutrient cycling and maintenance of healthy ecosystems. While there is substantial research into the identification of taphonomic signatures from facultative mammalian scavengers, early stage scavenging signatures by vultures remain unknown. Further, some vulture species are opportunistic predators, highlighting the need to define signatures observed in the course of normal scavenging behavior. We placed stillborn neonatal calves in an unoccupied pasture and used motion-trigger camera traps to quantify scavenging effort, then conducted necropsies to evaluate the effect of black vulture ( Coragyps atratus ) and turkey vulture ( Cathartes aura ) scavenging effort on carcass consumption. We measured the order of consumption of different tissue types to delineate which anatomic structures vultures consume first. Scavenging trials with higher numbers of vultures feeding on the carcass for longer were associated with decreased remaining tongue and abdominal viscera, and a larger umbilical wound. Greater maximum flock sizes were associated with decreased remaining tongue and abdominal viscera, a larger umbilical wound, and greater biomass consumption. Black vultures targeted the perineum and tongue earlier, while turkey vultures targeted the eyes, perineum, and tongue. These results are consistent with the idea that vultures prefer tissues that are easy to access and contain high nutrient content. These patterns form a distinctive taphonomic signature that can be used to identify early scavenging by black and turkey vultures. Our results demonstrate that criteria commonly used to identify livestock depredation by black vultures only document vulture presence and not predation. This distinction implies that new and more definitive criteria need to be developed and put into practice for more accurate decision criteria in livestock depredation compensation programs.

In 2023, an outbreak of highly pathogenic avian influenza occurred among critically endangered California condors (Gymnogyps californianus), and >21 died. We evaluated safety, immunogenicity, vaccination strategies, and correlates of antibody response of an influenza vaccine for poultry in black vultures (Coragyps atratus) and then California condors. We noted differences in antibody titers between vaccinated and unvaccinated birds (vultures p<0.004; condors p-<0.02) but no adverse effects of vaccination. All vaccinated vultures and 80% of vaccinated condors showed maximum measured antibody response within the published range associated with survival of vaccinated and virally challenged chickens. We noted weak evidence of higher antibody responses for birds given two 0.5-mL vaccines versus those given one 1-mL vaccine but no correlation between antibody titers and sex for either species or between antibody titers and bone lead concentrations in vultures. Our results prompted initiation of a vaccination program for condors that could reduce spread of this disease among highly threatened species.

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.

Scientific knowledge of vertebrate scavenging communities has increased over the last decades. However, there is a lack of information on the Neotropics. We aimed to describe the vertebrate scavenger community of the tropical dry forest of western Ecuador and to identify the factors influencing carcass consumption patterns by this guild. Between November 2022 and May 2023, we placed 64 experimental carcasses of different sizes in eight camera-trapping stations (32 carcasses for each category). At each station, we simultaneously placed two carcasses at least 100 m apart: one small-sized (chicken) and one medium-sized (goats or pigs) carcass. We fitted Generalized Linear Mixed Models to assess the effects of carcass size and season (rainy and dry) on the scavenger species richness and abundance, considering all scavenger species and by species group. We also fitted Linear Mixed Models to assess differences in carcass detection time, total consumption time and rate, using the carcass size, vulture abundance, and percentage of canopy cover as predictors. The scavenger community was dominated by obligate scavengers (i.e., vultures), and the species detected were the Black Vulture ( Coragyps atratus ), the Turkey Vulture ( Cathartes aura ), and the King Vulture ( Sarcoramphus papa ). Facultative mammalian scavengers such as Ocelot ( Leopardus pardalis ), Tayra ( Eira barbara ), Crab-eating Raccoon ( Procyon cancrivorus ) and domestic dog ( Canis lupus familiaris ) were recorded in a smaller number of carcasses. No facultative avian scavenger species were detected. Carcass size influenced all the variables analyzed, except the scavenger species richness. While the season influenced the vulture abundance, especially of S. papa . Facultative scavenger richness and abundance did not show significant differences. Carcass total consumption time was not explained by any of the variables included in the models. Both carcass detection time and consumption rates were influenced by carcass size, particularly in the case of consumption rates, where larger carcasses exhibited higher consumption rates than smaller ones. The dominance of vulture species in the scavenger community suggests that their ecological role is indispensable for the dry forest of western Ecuador. The loss of obligate scavengers could have important implications for ecosystem services and human well-being.

We describe the first documented case of anomalous double-clutching behavior in Coragyps atratus (Black Vulture) in northeastern North America. The female laid 2 eggs, which hatched successfully, and laid an additional clutch of 2 eggs, probably post-hatching, which it did not incubate, but were eventually consumed by the adults. Although we cannot determine the reason for this rare nesting behavior, the possibility of a double-brooding attempt was unlikely due to the timing of egg laying and the eggs not being incubated, yet we are not able to discard the possibility of an event of intraspecific nest parasitism. Since egg-laying is expensive in terms of energy, and may compromise adults' future reproduction and survival, this redundant expenditure suggests that (1) this pair of Black Vultures may have a resource-rich environment, and/or (2) the food availability derived from anthropogenic byproducts might be altering the biochemical cycles of reproduction timing. Further research is needed to ascertain whether the recent range expansion of Black Vultures in North America due to human activity may hide a threat that could compromise its populations in the future.

Black vultures ( Coragyps atratus ) provide invaluable ecological services through disposal of carrion and the mobilization of energy within the landscape. Human‐wildlife conflicts with these birds have increased as populations have grown and the species distribution has expanded. We identify critical science needed to understand conflict between black vultures and humans to inform effective management of this species in North America. It is imperative that diagnostic criteria supporting the identification of the impacts of black vulture on livestock be standardized and verified. Management guidelines that take these criteria into account will enable reduction in the potential for black‐vulture‐farmer conflict and allow us to properly investigate such conflict when it occurs. 黑头美洲鹫（ Coragyps atratus ）通过处理腐尸和促使景观中能量流动为生态系统提供了不可估量的生态服务。但随着种群增长和分布范围扩大，人类与这些鸟类之间的冲突也日益增加。我们明确了理解黑头美洲鹫与人类之间冲突的关键科学问题，为在北美对该物种的有效管理提供了信息。我们迫切需要制定标准化且被证实的判断标准，以准确评估黑头美洲鹫对家畜的影响。具有这些准则的管理指南将有助于减少黑头美洲鹫与农民之间潜在的冲突，并在冲突发生时使我们可以正确地开展调查。 Protocols, guidelines, and standards need to be developed that will allow black vultures and farmers to better coexist. A manual or protocol on identifying signs of black vulture attacks needs to be developed. Third parties need to be trained to objectively identify and certify when livestock have been definitively harmed or killed by vultures.

Negative 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.

Black 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.

Anesthetic protocols for non-invasive immobilization of Black Vultures (Coragyps atratus) and Turkey Vultures (Cathartes aura) for procedures lasting up to two hours are lacking. This study directly evaluated the safety and efficacy of a multimodal anesthetic protocol in 11 Black Vultures and 4 Turkey Vultures undergoing electroretinography (ERG). Vultures were anesthetized with intramuscular dexmedetomidine (5 μg/kg), midazolam (0.2 mg/kg), butorphanol (0.2 mg/kg), and ketamine (5 mg/kg) (DMBK), followed by isoflurane induction and maintenance. All vultures were mechanically ventilated to maintain consistent end-tidal CO2. Monitored parameters included sedation and recovery quality, heart and respiratory rates, hemoglobin oxygen saturation, non-invasive blood pressure, body temperature, and end-tidal concentrations of CO2, isoflurane, and oxygen. All vultures achieved profound sedation with smooth induction and a median isoflurane maintenance concentration of 1.4% for approximately two hours. Recovery was rapid and uneventful. Heart rates ranged from 60 to 119 beats/min. Mean arterial blood pressure averaged 149 mmHg in Black Vultures and 158 mmHg in Turkey Vultures, with Turkey Vultures showing significantly higher diastolic pressure. A second-degree heart block was detected in one Black Vulture but required no treatment. All ERG procedures were completed successfully. The DMBK protocol provided profound sedation in both species, maintained key cardiorespiratory parameters, including heart rate and arterial blood pressure, within a clinically acceptable range throughout isoflurane maintenance, and enabled uneventful rapid recovery. These findings support DMBK with the cardiorespiratory monitoring system as a safe and effective regimen for anesthetizing vultures and likely other similarly sized raptors requiring non-invasive immobilization.

The avian scavenger raptors guild of Patagonia, the southernmost region of South America (37–56°S), comprises 3 species of obligate scavengers and 7 species of facultative scavengers. Despite the species richness, there is little information about the anthropogenic threats this guild might face. Here, based on 164 h of observations and photographic records across 3 austral winters, we reveal a broad range of lesions (missing legs, digits or talons, fractures, luxations, pododermatitis, necrosis, hyperkeratosis, and beak and ocular lesions) and mortalities among scavenger raptors in Argentine Patagonia at 2 anthropogenic food-rich sites located 1,750 km apart at 38° and 54°S. We photographed 146 individuals with 174 physical lesions and found 61 dead individuals, including one obligate scavenger species (Black Vulture, Coragyps atratus) and 4 facultative scavenger species (Crested Caracara, Caracara plancus; Chimango Caracara, Daptrius chimango; White-throated Caracara, D. albogularis; and Black-chested Buzzard-Eagle, Geranoaetus melanoleucus). Ninety percent of the lesions we recorded on the individuals were located on their hindlimbs. None of the carcasses we found exhibited any apparent lesions. The precise nature and origins of these lesions and mortalities remain uncertain. However, the hindlimb lesions align with the effects of leg-hold traps, while poisoning emerges as the most likely cause of mortality among individuals foraging at these anthropogenic food-rich sites. These findings suggest a notable human-induced threat to the avian scavenger raptors guild in Patagonia. El gremio de rapaces carroñeras de la Patagonia, la región más austral de Sudamérica (37–56°S), comprende 3 especies de carroñeros obligatorios y 7 especies de carroñeros facultativos. A pesar de la riqueza específica, hay poca información sobre las amenazas antropogénicas que este gremio podría enfrentar. Basándonos en 164 h de observaciones y registros fotográficos a lo largo de tres inviernos australes, revelamos una amplia gama de lesiones (amputación de patas, dedos o garras, fracturas, luxaciones, pododermatitis, necrosis, hiperqueratosis, y lesiones oculares y del pico) y mortalidades de rapaces carroñeras en la Patagonia argentina en dos sitios de recursos alimentarios antropogénicos ubicadas a 1750 km de distancia a 38° y 54°S. Fotografiamos 146 individuos con 174 lesiones y encontramos 61 individuos muertos, incluyendo una especie carroñera obligada (Coragyps atratus) y cuatro especies carroñeras facultativas (Caracara plancus, Daptrius chimango, D. albogularis y Geranoaetus melanoleucus). El 90% de las lesiones que registramos en los individuos se encontraban en sus patas. Ninguno de los especímenes muertos que encontramos presentaba lesiones aparentes. La naturaleza precisa y el origen de estas lesiones y mortalidades son inciertos. Sin embargo, las lesiones en las patas concuerdan con los efectos de las trampas de zorros, y el envenenamiento emerge como la causa más probable de mortalidad en los individuos que forrajean en estos sitios de recursos alimentarios antropogénicos. Estos hallazgos sugieren una notable amenaza de origen antrópico para el gremio de rapaces carroñeras en la Patagonia. Palabras clave: caracaras, Coragyps atratus, extremidades posteriores, fotografía de campo, Geranoaetus melanoleucus, trampas para zorros.