Study finds H5N1 widespread in dead black vultures: full analysis
Black vultures may be emerging as one of the clearest wildlife casualties of the current H5N1 wave. A University of Georgia-led study published in Scientific Reports found that 84.3% of dead black vultures tested from seven Southeastern states in 2022–2023 were positive for clade 2.3.4.4b highly pathogenic avian influenza A(H5N1), adding weight to concerns that this scavenging species is unusually vulnerable during the North American epizootic. (nature.com)
The finding lands against a broader backdrop of sustained H5N1 pressure in wild birds since the virus was first detected in North America in late 2021. Recent reviews and federal updates describe a panzootic that has caused major mortality in wild birds, poultry, and a growing list of mammalian species, while USGS says mortality events in wild birds are continuing across all four U.S. flyways. (nature.com)
In the black vulture paper, UGA and Southeastern Cooperative Wildlife Disease Study investigators collated diagnostic data from carcasses and swabs submitted during the early outbreak period. Beyond the headline prevalence, they reported that 53 of 73 birds receiving gross evaluation had enlarged, mottled spleens and livers, and all 14 birds examined histologically showed widespread severe necrosis in those organs with influenza A virus labeling. The paper argues the species’ biology may be part of the problem: black vultures feed communally, aggregate in large numbers, and may scavenge infected carcasses, including those of other vultures, creating repeated exposure opportunities. (nature.com)
UGA’s public summary of the study underscored that point. Lead author Nicole Nemeth, who heads the research and diagnostic service at SCWDS, said the team was surprised by how many birds tested positive and described observations suggesting black vultures were eating dead cohorts, which may have helped keep transmission going beyond the typical bird flu season. That matters because black vultures are abundant, wide-ranging, and frequently encountered near farms, roadsides, landfills, and rehabilitation settings, where veterinarians and allied animal health teams may be the first to field questions. (news.uga.edu)
There does not appear to be much formal outside commentary on this specific paper yet, but the broader expert view aligns with its implications. USGS has emphasized that HPAI is now an ecological and wildlife health issue as well as an agricultural one, and APHIS continues to frame avian influenza as a reportable disease requiring veterinary evaluation and rapid communication with animal health officials. CDC guidance for veterinarians and animal caretakers also stresses precautions when working with animals suspected or confirmed to have H5N1 infection, reflecting the occupational exposure piece that continues to shadow wildlife and mixed-species practice. (usgs.gov)
Why it matters: For veterinary professionals, this study is less about vultures alone than about surveillance, triage, and risk communication. A dead scavenger bird, especially in clusters or with neurologic signs before death, may represent a more meaningful H5N1 signal than previously appreciated. Wildlife rehabilitators, diagnostic labs, poultry veterinarians, and companion animal teams counseling pet parents about exposure to dead birds all sit downstream of that reality. The paper also adds a practical reminder that transmission ecology may not be limited to migratory waterfowl patterns; scavenging behavior can create local, persistent exposure loops that complicate assumptions about seasonality and species risk. (nature.com)
What to watch: The next questions are whether similar mortality patterns will be documented in other scavenging species, whether surveillance programs begin treating vultures as higher-value sentinels, and whether state or federal agencies refine handling, reporting, or biosecurity recommendations for wildlife professionals and veterinarians as the 2026 H5N1 picture evolves. (usgs.gov)