Decline of the Endangered Morro Bay Kangaroo Rat in California

Abstract The Morro Bay kangaroo rat Dipodomys heermanni morroensis occurs in the vicinity of Morro Bay (specifically in and near Los Osos) in western San Luis Obispo County in coastal central California. It was listed as endangered pursuant to the U.S. Endangered Species Conservation Act in 1970 and subsequently the U.S. Endangered Species Act in 1973. Field research from the late 1950s to the mid-1980s has documented a rapid population decline. Despite many efforts, researchers have not captured the Morro Bay kangaroo rat since 1986, and the last captive individual died in 1993. We review the biology and conservation status of the Morro Bay kangaroo rat, including taxonomy and genetics, soil type and burrows, history of decline, primary causes of decline, breeding in the wild and in captivity, habitat restoration, and threats. In particular, there are two primary causes of decline. First, development (urban, agricultural, and industrial) has resulted in direct loss of habitat. Second, in the absence of f...