Status of an Invading Mainland Jackrabbit on Cerralvo Island, Gulf of California

We report the first observations of the black-tailed jackrabbit (Lepus californicus) on Cerralvo Island, Baja California Sur, Mexico. Evidence suggests a self-sustaining population. Analysis of available records indicates no previous record of Lepus on the island. Introduction of the jackrabbit to the island appears to have occurred between 1960 and 1991.