By Keith L. Bildstein, Ph.D., Sarkis Acopian Director of Conservation Science
and Lindy Thompson, Ph.D., Hawk Mountain Research Associate
Hawk Mountain Sanctuary
10 November 2016
Yes, I admit it. We name our satellite-tracked vultures.
Some of our colleagues disagree with this, arguing that naming one’s study animals “personalizes” them in ways that make our observations less scientific. But primatologist Jane Goodall and Nobel Prize laureate Konrad Lorenz named their study animals, and I have never doubted the scientific rigor of their work. Naming animals as individuals makes their individual behavior easier to remember. With more than 75 vultures tracked by satellite so far, numbers or alpha-numeric codes simply do not work as well, as names help to separate and categorize the birds in question and keep the stories of their movements in mind.
“Homebody,” a South African Hooded Vulture, is a case in point.
As a nestling, Homebody was fitted with a GSM satellite tracking device by Walter Neser and Kerri Wolter at the Olifants River Private Game Reserve in northeastern South Africa just west of Kruger National Park on the 19th of October, 2013. Unfortunately, the unit never worked, and we decided to try to re-trap and refit Homebody with a new unit in the summer of 2014. Trapping a vulture once is relatively easy. We have caught hundreds of them. Trapping the same bird twice, however, is a different matter entirely. In 2004 we caught and placed data loggers in the body cavities of six Turkey Vultures to record their heart rates and core body temperatures. The following year the birds needed to be recaptured and their data loggers removed to retrieve the accumulated data. It took then graduate student and now Dr. Jamie Mandel, hundreds of hours during much of the next spring and summer to recapture four of the birds. The other two were never recaptured.
We had allotted a week of field time to recapture Homebody to replace its malfunctioning unit with a working one. Three days unsuccessfully attempting to do so had us at wits end. Hooded Vultures defer to larger African White-backed Vultures at carcasses, and Homebody, even though present at our trapping site, hardly ever got close to the carcass, let alone the snares that we had set around it. But then something happened that one only dreams about. We were late getting to our trap the fourth day of field work, and lo-and-behold Homebody and several other Hoodies were already at the site picking up small pieces of the bait that remained from the previous day. Disappointed by their early arrival we drove our Land Rover toward the birds, flushing all of them into the air. Miraculously, Homebody, after taking off to escape our approach, flew into a thorn bush and became entangled on one of the lower branches, which had slid between its body and the backpack harness we had used to attach the tracking device. Within seconds we ran to the bush and hand-grabbed Homebody, disentangled it, and brought it back to base camp. We then removed the malfunctioning unit and placed a new, fully functional unit on it. Within 45 minutes of its miraculous recapture, we were celebrating our “lucky day” over a couple of beers. A once-in-a-million event allowed us finally to satellite track the young vulture that had been tagged eight months earlier.
This alone makes for a great story. But Homebody’s epic journey does not end there. Last week–and more than two years later–we received an email from Colin Rowles, game warden at the Klaserie Private Nature Reserve. Colin said a staff member on fence patrol had found Homebody dead at an impala carcass. When Colin went to collect the transmitter, he found that a Martial Eagle had consumed most of the Hooded Vulture. Jackal tracks at the carcass lead him to believe that a jackal had killed Homebody. We hope to place Homebody’s unit, which is still working, on another Hooded Vulture as early as this December.
Even though the story ended tragically for Homebody, we have placed similar units on other Hoodies, both in The Gambia and Ethiopia, as well as in South Africa. Although several of these birds have died, most are still alive and transmitting important information. The data we are now gathering will allow us to offer advice on how best to protect these birds, as well on the factors that most threaten them. Costs associated in doing this are not inconsequential. Homebody’s unit cost four thousand US dollars and download information from the unit cost us close to 600 dollars per year. The information, however, is “priceless.” Understanding the ecological neighborhoods of Critically Endangered Hooded Vultures is key to protecting them.
To learn more about our work with Hooded Vultures and other species of scavenging raptors, or want to support our field efforts financially, contact me at Bildstein@hawkmtn.org.
My next blog will describe our recent field work in Senegal, where Hooded Vultures remain very much in evidence.