Deer-Car Accidents in Southern Michigan

Collisions of cars with white-tailed deer (Odocoileus virginianus) were studied in southern Michigan in 1966 and 1967. Most of the 2,566 accidents studied occurred at dawn, dusk, or after dark with peaks at sunrise and 2 hours after sunset. Accidents were highest on weekends when evening traffic was greatest. A low seasonal peak in collisions occurred in May and a high one in November. Sex ratio of the annual kill was predominately female, but it shifted in favor of males during seasonal peaks. Causes of the peaks seemed to be primarily rutting activities, with hunter disturbance and food of lesser importance. Accidents were related to habitat type approximately according to the prevalence of the type. Accidents were most common at speeds of 80-95 km/h (50-59 mph), and the deer was killed in 92 percent of the accidents. Human injuries occurred in less than 4 percent, and most resulted from secondary collisions.