The black-tailed jackrabbit (Lepus californicus) is one of the most widespread herbivores on western rangelands. It occurs from Canada to northern Mexico and from the west coast to the Central Plains of the U.S. (Hansen and Flinders, 1969). Apparently they favor an open or semi-open habitat because they depend on speed and distance to escape predators (Ingles, 1947; Leopold, 1959).

Since black-tailed jackrabbits are so widely distributed, they must be able to utilize a wide array of food sources. Thus food-habit studies conducted in one area may not apply to another. In previous studies, jackrabbits and cattle exhibited considerable dietary overlap (Hansen and Flinders, 1969; Sparks, 1968; and Uresk, 1978). Griffing and Davis (1976) reported on gross examination of stomach contents and feeding behavior of blacktailed jackrabbits in southeastern New Mexico, but not on detailed food habits. However, information on food habits of the black-tailed jackrabbit in New Mexico is lacking but is needed for proper management of these herbivores.

The objective of this study was to compare botanical · composition of black-tailed jackrabbit diets from different vegetational types, using microhistological analysis of fecal pellets.