PS 48-13 - The vulture restaurant is open: A study on the feeding ecology of black and turkey vultures

Thursday, August 10, 2017
Exhibit Hall, Oregon Convention Center
Camille C. De Jesus, Doris Duke Conservation Scholars Program, Wesley W. Boone IV, Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, Ray Carthy, FL Coop Fish and Wildlife Unit, University of Florida, Gainesville, FL, Christina M. Romagosa, Wildlife Ecology and Conservation, University of Florida, Gainesville, FL and Nichole Bishop, School of Natural Resources & Environment, University of Florida, Gainesville, FL

Behavioral studies are an important component in understanding an organism’s ecology. To date, there is limited research on the behavioral ecology of the American vulture species, Turkey Vulture (Cathartes aura) and Black Vulture (Coragyps atratus). Specifically, few studies have examined Northeast Florida populations’ feeding ecology and interactions with each other. An initial step in behavioral ecology studies is the development of an ethogram. Therefore, the purpose of this study was to construct an ethogram for black and turkey vultures and describe in situ behaviors related to feeding. Both vulture species were observed during June and July in the coastal area of St. John’s County and Flagler County in Florida. We observed vultures feeding opportunistically at various times of day (generally 11am to 7pm). Individuals from either species were chosen at random and observed for 5 minutes. We directly observed at 64 vultures (12 turkey vultures, 52 black vultures). Sequence and transition data were also recorded during feeding events to develop kinetomatic diagrams.


During feeding events, our ethogram identified 31 behaviors for black vultures and 20 behaviors for turkey vultures. Behavior was highly variable in black vultures. The most frequently shared behavior was only represented in 37% of individuals (range 3-37% individuals exhibiting each behavior). Behavior was much more uniform among turkey vultures with 80% of individuals engaging in the most common behavior (range 10-80% individuals exhibiting each behavior). The most common behaviors among black vultures were biting at food (37%) and standing in place (37%); the most common behavior among turkey vultures was raising their head and scanning (80%). Aggressive behaviors, such as attacking, chasing, and attempts to attack, were absent in turkey vultures, but present in black vultures. Other studies on vulture feeding behavior support our results by highlighting the cooperative nature of turkey vultures feeding (e.g. queuing up to feed) and the antagonistic actions demonstrated by black vultures feeding (e.g. attacking). We intend to further develop data collection methods so that black vulture and turkey vulture feeding behavior can be standardized for future comparative studies.