By Keith L. Bildstein, Ph.D.
Sarkis Acopian Director of Conservation Science
19 May 2013
Over the course of the last decade my colleagues and I have attached satellite-tracking devices on more than 30 turkey vultures and then followed their movements across North, Central, and South America. Included in the mix have been individuals representing three of the six recognized subspecies: the Cathartes aura septentrionalis race that breeds in Pennsylvania, the C. a. meridionalis race that breeds in the Pacific Northwest and central Saskatchewan, and the C. a. ruficollis race that breeds in central Argentina.
We also have wing-tagged more than 500 individuals in these areas, as well as in Venezuela and the Falkland Islands where a fourth race, C. a. falklandica, breeds. That said we have yet to study movements of the two remaining subspecies of turkey vultures, C. a. jota and C. a. aura. Jota occur in South America’s “southern cone,” and aura ranges from the southeastern-most corner of the United States through Mexico and Central America.
The movement data that we have collected so far indicate that the four races we have studied exhibit distinctively different migration geographies, which we are currently analyzing in detail. Our long-term goal, however, is to place tracking devices on individuals of all six races so that we can better understand variation and flexibility throughout the movement ecology of this, the world’s most successful, scavenging bird of prey.
Late last year we received funding to tag six individuals of the Cathartes aura aura subspecies. If all goes according to plan, we will do so this week. As I draft this entry, Hawk Mountain’s Senior Research Biologist, Dr. Jean-Francois Therrien, and I are on our way to Tucson, Arizona where we will meet up with Dr. Marc Bechard, Distinguished Professor of Biology at Boise State University, and Dr. Jennie Duberstein, Education and Outreach Coordinator with the USF&WS Sonoran Joint Venture Project, to plan the details of our trapping effort. Simply put we need to catch and tag six birds in eight days. Although it sounds simple enough, none of us has ever worked with vultures in the American Southwest and I, for one, am a bit apprehensive.
Jennie has laid the ground work for a successful effort by locating and convincing a local land owner to serve as our on-site logistical coordinator. Although I have yet to meet Doug Loney, Jennie assures me that he has been pre-baiting a site in front of his home in the Sonoran Desert for more than a month, and that upwards of 80 turkey and black vultures have been visiting it regularly. The forecast for the coming week calls for sunny and hot weather, and our team is “pumped” up and ready to go. Tomorrow we will visit the site.
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