RESEARCH NOTES: HABITAT MANAGEMENT FOR THE ENDANGERED STEPHENS' KANGAROO RAT: THE EFFECT OF MOWING AND GRAZING

Abstract

Stephens' kangaroo rat (Dipodomys stephensi) is considered to be threatened by the state of California (California Department of Fish and Game 1972, 2000) and endangered by the federal government (Kramer 1988). The proximate factor leading to this status was urban expansion in western Riverside County, California. The more distal factor is that this species has an anomalously small geographic range (ca. 28,000 ha) for its body size (Bleich 1977). Currently, this species is managed on a small number of protected reserves in western Riverside County, and there is much interest in understanding how habitat manipulation might influence population parameters. Dipodomys stephensi occurs in sparsely vegetated annual grasslands and adjacent shrubby habitats (Bleich 1977, O'Farrell 1990, Price et al. 1991), although it appears to generally favor forb-dominated grassland habitat; at least 2 studies (Price et al. 1991, D. A. Kelt and E. S. Konno unpublished data) reported that this species was never observed in adjacent coastal sage-scrub habitat. Reduction of shrub cover has been documented