FLIGHT BEHAVIOR OF BLACK AND TURKEY VULTURES: IMPLICATIONS FOR REDUCING BIRD-AIRCRAFT COLLISIONS
TRAVIS L. DEVAULT,1 Department of Forestry and Natural Resources,
195 Marsteller Street, Purdue University, West Lafayette, IN 47907, USA
BRADLEY D. REINHART, Savannah River Ecology Laboratory, Drawer E, Aiken,
SC 29802,USA
I LEHR BRISBIN, JR., Savannah River Ecology Laboratory, Drawer E, Aiken,
SC 29802, USA
OLIN E. RHODES, JR., Department of Forestry and Natural Resources, 195
Marsteller Street, Purdue University, West Lafayette, IN 47907, USA
Abstract: Mid-air collisions with black vultures (Coragyps atratus)
and turkey vultures (Cathartes aura) regularly cause substantial
damage to military and civilian aircraft. Infonnation concerning the flight
behavior of black and turkey vultures potentially could improve predictive
models designed to reduce bird trikes by aircraft. We examined the flight
behavior of black and turkey vultures at the Savannah River Site (SRS)
in South Carolina, USA, and determined whether flight characteristics
were predictable with respect to weather and time variables. We captured
birds at their primary roost and subsequently relocated them via aerial
telemetry from 11 February 2002 through 29 January 2003. One hundred eighty
of 326 locations (55%) for 8 black vultures and 129 of 206 locations (63%)
for 5 turkey vultures were of flying birds. Black vultures flew at an
average altitude of 169 ± 115 (SD) m above ground level, whereas
turkey vulture flight altitude averaged 163 ± 92 m. Our results
contrast studies that reported less fre- quent and lower altitude flights.
The flight behavior of both species appeared to be influenced minimally
by weather and time variables. However, we were unable to construct useful
models predicting aspects of flight behavior using the variables we measured
(all models had R2 or pseudo R2 values <0.10).
We suggest that other factors, such as food availability, inter- and intra-5pecific
interactions, and physiological demands playa larger role in vulture flight
behavior than the variables we measured. Our results suggest that the
development of bird avoidance strate- gies by aircraft operators should
consider the variability of flight behaviors of black and turkey vultures
across their ranges. Future research emphases should shift from examinations
of the effects of local conditions on flight behavior to the elucidation
of factors contributing to differences in flight behavior among regions.
JOURNAL OF WILDLIFE MANAGEMENT 69(2}:592-599; 2005
Key words: aviation, bird-aircraft collisions,
black vulture, Cathartes aura, Coragyps atratw, flight behavior,
military, movements, radiotelemetry, South Carolina, turkey vulture.
SREL Reprint #2857
DeVault, T. L., B. D. Reinhart, I. L. Brisbin, Jr. and O. E. Rhodes, Jr. 2005. Flight behavior of black and turkey vultures: implications for reducing bird-aircraft collisions. Journal of Wildlife Management 69:592-599.
