Dr. Corinne Kendall giving a presentation on vultures in Tanzania.
National Geographic Society grantee Corinne Kendall studied vulture biology and conservation at Princeton and now works for North Carolina Zoo putting her knowledge to work in on-the-ground (and in-the-sky) research in Tanzania. She’s also passionate about education, managing a teacher training program in Uganda and teaching at zoos and universities across the United States. We asked her about her recent findings about these critically endangered birds.
Why are vultures so important to the overall health for life in Africa?
Vultures play a critical role in disease control and waste removal. They are actually one of the most important scavengers in Africa and are believed to consume even more carrion than mammalian scavengers like hyenas. Vultures also eat rapidly and feed in large groups which allows them to consume carrion quickly. This reduces the risk of disease spread from flies or bacteria. Vultures are resistant to many diseases so they don’t contract or spread diseases like tuberculosis or brucellosis even if the animals they are consuming died from those causes.
Vultures have the advantage of incredibly efficient soaring flight which allows them to travel large distances in short amounts of time. White-backed vultures are also highly social. These two characteristics make vultures uniquely capable of responding to fluxes in food availability created when a large animal dies or during an epidemic. As a result they can be particularly important for reducing disease spread during an outbreak.
What can vultures teach us about the spread of anthrax and other animal mortalities?
Vultures respond to disease outbreaks quickly and reduce the spread by consuming carrion without contracting the disease. In Tanzania, Wildlife Conservation Society biologists and I have satellite-tagged White-backed vultures and recently had a unique opportunity to understand how anthrax spreads during an outbreak using our tagged vultures. Because birds stop for extended periods when feeding at a carcass, we were able to identify locations of animals that died of anthrax during a recent epidemic in Ruaha National Park. Using our tagged birds we can assess when and where the outbreak started, how it spread, and when it ended. In collaboration with Tanzanian National Parks, we were even able to identify contaminated carcasses so that rangers could destroy some carcasses and help to reduce the spread of anthrax.
Vultures might be able to help us understand other animal mortalities as well. For instance, there is concern about a giraffe skin disease which has become very common in Ruaha National Park.
It is not known if this disease affects mortality rates in giraffe. Using vultures, we may be able to find giraffe carcasses more rapidly and assess how severe the skin disease was in the deceased individual.
Why are African vultures declining?
African vulture populations have declined precipitously in the last three decades and many species are now considered endangered or critically endangered. Poisoning is the primary cause of decline. Poisoning occurs when people put pesticides onto livestock carcasses when cows or other domestic animals are killed by lions and hyenas. These retaliatory killings are intended to kill the carnivores, but vultures are the more common victims of poisoning. In some cases, poachers have also begun poisoning vultures either for their body parts or because they want to reduce vulture numbers so that the birds don’t alert rangers to elephant carcasses, from individuals that have been recently poached.
Vultures FEEDING ON ANIMAL CARCASSES HELPS SCIENTISTS TRACK THE SPREAD OF DISEASES SUCH AS ANTHRAX. Photograph by James Smoliga.
What can be done to save Africa’s vultures?
Wildlife Conservation Society and North Carolina Zoo are working closely with Tanzanian National Parks to ensure a safe future for vultures in Tanzania. We have conducted ranger trainings on how to respond to poisoning events, such as ways to collect evidence, how to care for sick birds, and how to properly dispose of the poisoned carcass. In addition, in September 2017 we held Tanzania’s first ever Vulture Awareness Day. This event attracted hundreds of people and media attention in Tanzania and communities were amazed to learn about the important role that vultures play in the environment and what they can do to save them. It really helped raise the profile of these sometimes overlooked birds.
Is there hope for African vultures?
The threats to African vultures are great and poisoning can kill a large number of birds very quickly. However, there is hope for African vultures. Recent studies from Wildlife Conservation Society and North Carolina Zoo in Ruaha National Park, Tanzania suggest that this park may be a critical stronghold for African vultures. Populations appear to be stable and poisoning appears to be infrequent in this area. We are optimistic that vulture populations in southern Tanzania can flourish even though declines are continuing elsewhere.