Turkey Vulture Migration Project...

 

Project Description:


The Turkey Vulture (Cathartes aura) is the most widely distributed, as well as the most abundant, of all scavenging birds of prey.  The species, which occurs only in the new World, can be seen as far north as southern Canada and as far south as Tierra del Fuego at the southern tip of South America.  Turkey Vultures also occur on many large and small islands including Vancouver Island, Canada, Cuba and Puerto Rico in the Caribbean Sea, and the Falkland Islands in the South Atlantic.  Six races or subspecies of Turkey Vultures are recognized by biologists:  including septentrionalis in eastern North America, meridionalis in western North America, aura in Mexico, parts of the Caribbean and Central America, ruficollis in southern Central and northern and central South America, jota in South America and falklandica in southern South America and the Falkland Islands.  The scientific name for Turkey Vulture, Cathartes aura, translates as “breezy cleanser,” most likely a reflection of its soaring and scavenging life style.

Scientists consider North American populations of Turkey Vultures to be partial migrants, in that northern populations of the species migrate, whereas southern populations, in general, do not.  Eastern North American populations of the species typically migrate no farther south than Florida and Texas.  Western populations travel at least as far as Colombia and Venezuela, and some experts believe that some western birds may travel as far south as Brazil and Argentina.  Millions of migrating Turkey Vultures have been counted annually at migration watch sites in Mexico, Costa Rica, and Panama.

As scientists we are interested in learning more about the movement ecology of this extremely successful raptor, which seems to have one of the most flexible of all avian migration systems.  Earlier reports from northern South America suggest that northern migrants, which are larger and more massive than local residents, dominate the latter when they arrive on their wintering grounds in December each year.  The extent to which such dominance affects the breeding schedules and numbers of southern birds remains unknown, as does the extent to which individual migrants visit an over-winter in the same location each year.

In the spring of 2003 Hawk Mountain Sanctuary initiated a long-term study of migration behavior in Turkey Vultures in an effort to learn more about the extent, causes, and consequences of their annual journeys.  To date scientists at the sanctuary and its collaborators have placed tiny radio tags monitored by satellite on 21 Turkey Vultures in an effort to follow their outbound migrations south each autumn and their return migrations north each spring.  Five of the satellite-tracked birds also had a data logger surgically implanted in their body cavities.  The loggers record both core body temperature and heart rate.  Recovering these data loggers allows us to determine fluctuations in both body temperature and heart rate associated with day-night cycles and migration activity.  The Sanctuary and its collaborators also have placed red, yellow, or light blue numbered wing tags on more than one hundred Turkey Vultures in Canada, Venezuela, and the United States.  (If you happen to see one of these birds please report it to the Sanctuary).

Hawk Mountain scientists also have been surveying the sizes of Turkey Vulture winter and summer populations in seven eastern United States and British Columbia, Canada, as well as in Costa Rica, Panama, Venezuela, Argentina, and the Falkland Islands.    Our plan is to lay the ground work for a long-term monitoring effort that will track regional and continental populations of this widespread and common scavenger in hopes of avoiding catastrophic declines in its populations similar to those that have occurred in Old World Vultures in many parts of Africa and southern Asia.

A second goal of our research is to provide the general public, including school children, with the ability to track the daily movements and whereabouts of these important scavengers across North and South America.

Our website was put together by a team of raptor biologists from Hawk Mountain Sanctuary and the Falcon Research Group in Bow, Washington, including, David Barber, Mark Prostor, and Don McCall.  Their support for this work reflects both their concern for and deep curiosity of these remarkable birds.  Bud Anderson, director of the Falcon Research Group has been particularly generous in making this website possible.

Although often maligned, Turkey Vultures are great natural ambassadors and teachers.  This “everywhere bird” is quickly becoming “everyone’s bird,” and this website will help establish the continental connections these “sanitation engineers” are bringing about, both ecologically and sociologically.  

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