They favor arid regions and areas of short grass rangeland from sea level to about 3,800 m. They also frequent the agricultural land in California where they are a major pest of crops and fruit trees. Negative Due to the removal by European settlers of its natural predators such as the coyote and kit fox, the black-tailed jackrabbit has undergone incredible population explosions in which crops, orchards and rangelands have suffered. Large herding attempts have netted as much as 20,000 hares at a time, and population densities often reach 100 animals per square km. As with many hares, Lepus californicus populations undergo drastic fluctuations in regular cycles every 9-10 years.
Populations increase to great abundance and then suddenly decline for unknown reasons.
In some years more then 90 per cent of the western populations die from tularemia, which may or may not be related to the population cycling phenomenon. This name was later shortened to jackrabbit. The hares and jackrabbits. U.K. Grzimek's Encyclopedia of Mammals. Nowak, R.M. and J.L Paradiso.