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A new study suggests avian influenza is hitting black vultures hard.<\/p>\n
More than four out of every five dead black vultures examined by University of Georgia researchers tested positive for highly pathogenic avian influenza, according to the new study<\/p>\n
The actual toll of the virus on the integral species is likely exponentially higher, though, the researchers warn.<\/p>\n
These birds may \u201crepresent tens or hundreds of thousands of black vultures,\u201d says Nicole Nemeth, lead author of the study and head of UGA\u2019s Southeastern Cooperative Wildlife Disease Study\u2019s research and diagnostic service. Nemeth is also an associate professor in UGA\u2019s College of Veterinary Medicine.<\/p>\n
Black vultures\u2019 indiscriminate scavenging appears to sustain transmission of the virus beyond the typical bird flu season, the study found.<\/p>\n
This year-round cycle of disease is concerning.<\/p>\n
Sustained transmission means more opportunities for the virus to mutate. And more opportunities to mutate mean the potential to become more virulent and pose a bigger threat to other species, including humans. (There is currently no evidence this is happening in the vulture population, but the potential remains unknown.)<\/p>\n
\u201cEvery day, more carcasses would appear, and we could see that the black vultures were eating their dead cohorts,\u201d Nemeth says. \u201cFrom a survival perspective, that\u2019s smart. It\u2019s a ready-made, available food source.<\/p>\n
\u201cBut it perpetuates this cycle of disease within the vulture population year-round.\u201d<\/p>\n
Researchers in the cooperative tested 134 dead black vultures from seven states in 2022 and 2023. More than 84% of the birds tested positive for highly pathogenic avian influenza, or H5N1.<\/p>\n
\u201cThis is just a portion of the population that dies from the virus,\u201d says David Stallknecht, coauthor of the study and a professor emeritus of wildlife diseases and population health at UGA. \u201cAnd the portion that dies is just part of the bigger picture.\u201d<\/p>\n
\u201cThis is a very important group of birds, ecologically speaking,\u201d Nemeth says. \u201cIn areas where vulture populations have been diminished, there are a lot more dead animals left in the landscape, which actually has been shown to contribute to increased diseases in people, wildlife, and domestic animals.\u201d<\/p>\n
Black vultures are abundant in the Southeast, but vulture species have been declining globally. Rampant bird flu won\u2019t help.<\/p>\n
\u201cWe\u2019re not really thinking about just one virus,\u201d says Rebecca Poulson, coauthor of the study and an assistant professor of wildlife diseases and virology.<\/p>\n
\u201cAvian influenza is incredibly diverse. These highly pathogenic viruses continue to circulate and mix up, and it\u2019s creating a huge potential diversity of different viruses, many of which wildlife species in North America may not have seen before.\u201d<\/p>\n
That could be devastating to not just bird populations but other animals vulnerable to the disease as well.<\/p>\n
Previous research has suggested about half the vultures that are infected with bird flu survive. Scientists found antibodies in the survivors, meaning they should have some protection against future outbreaks.<\/p>\n
\u201cThat means that the virus is incredibly transmissible in these populations,\u201d Stallknecht says. \u201cBut from a conservation standpoint, it means there\u2019s survival as well.\u201d<\/p>\n
If there\u2019s a silver lining to this study, that\u2019s it, the researchers say. The US black vulture population is substantial enough that Stallknecht isn\u2019t too worried about the species\u2019 decline\u2014not yet anyway.<\/p>\n
But for endangered species, even a few deaths could spell disaster.<\/p>\n
A 2023 outbreak of bird flu in California condors, for instance, killed at least 20 birds. There are fewer than 600 condors. About a third of them are housed in captivity.<\/p>\n
\u201cWhen you have a population of only a few hundred animals, 20 dying is a big deal,\u201d Stallknecht says.<\/p>\n
Also referred to as bird flu, this highly pathogenic H5 influenza was first detected in the 1990s and has wreaked havoc on wild and domesticated bird species on and off ever since.<\/p>\n
It began infecting other animals from dairy cows and house cats to dolphins and bears.<\/p>\n
\u201cEveryone is always on the edge of their seat worried about whether it\u2019s going to mutate enough to go from person to person, mammal to mammal,\u201d Nemeth says.<\/p>\n
\u201cThis virus is scary. It\u2019s changing. And it\u2019s doing continual damage to our wildlife\u2014on top of all the other challenges these wildlife already face.\u201d<\/p>\n
The research appears in Scientific Reports<\/a>.<\/p>\n