COYOTE PREDATION AND HABITAT SEGREGATION OF WHITE-TAILED DEER AND MULE DEER

Abstract

Predation has been proposed as a major factor maintaining segregation among species of ungulates, but predator–prey interactions have not been observed to test this idea directly. Here, observations of coyote (Canis latrans) packs hunting deer are used to show that mule deer (Odocoileus hemionus), which typically stand high on slopes and on rugged terrain, increased both their risk of being encountered and attacked by coyotes by standing low rather than high on slopes. The risk incurred at certain heights was not fixed: a mule deer's risk of being approached by coyotes was also affected by the height of other mule deer groups present during the same hunt. White-tailed deer (O. virginianus), which typically use gentle terrain, were not similarly disadvantaged by remaining low on slopes or on flat terrain. When confronted by coyotes, mule deer moved to and up slopes, whereas white-tails moved down and away from slopes. Species differences in behavior were independent of starting position and were observed f...