Diets of Black Vultures and Turkey Vultures in Coastal South Carolina, USA with a Review of Species' Dietary Information

Abstract

Food availability resulting from anthropogenic land-use changes may have contributed to the recent increase of Cathartes aura (Turkey Vulture) and Coragyps atratus (Black Vulture) populations. We assessed anthropogenic contributions to diets of these species by analyzing 176 pellets collected from communal roosts in coastal South Carolina. To provide further insight into diets, we conducted a literature review of pellet-based studies for both species. Our pellet analyses demonstrated consumption of 12 mammal species with Odocoileus virginianus (White-tailed Deer) as the primary food item, present in 65% of samples and constituting 35% average percent volume in pellets. Mephitis mephitis (Striped Skunk) and Procyon lotor (Raccoon) were also commonly consumed. Presence of anthropogenic items in 47% of pellets indicated substantial garbage consumption. Our review consisted of 14 studies and revealed wide variability in diet across study sites, with large mammals (>15 kg) typically comprising the majority of species consumed. We suggest that increasing deer populations provide an important source of carrion for vultures in this area and likely throughout eastern North America. Ungulate populations, roadkill, and garbage appear to contribute considerably to Turkey Vulture and Black Vulture diets. As such, mitigation of human–vulture conflict will require effective garbage and roadkill management as Turkey Vulture and Black Vulture populations increasingly expand.