In the early 1970's composition counts indicated that low fawn survival was the principal cause of the continued decline in the North Kings population. Predation by mountain lions, black bears and coyotes was identified as the principal cause of fawn mortality. Of the 90 fawns radio-equipped in the population since 1978, 43 (48 percent) have been killed by predators. Of the fawns killed by identified predators, 47 percent were taken by mountain lions.
Although predation is probably not responsible for the decline of the deer population, it is probable that predation especially by mountain lions-is preventing preventing its recovery. This level of predation seems to indicate a high mountain lion density, or at least a high mountain lion: deer ratio.
Recent track surveys indicate that mountain lion densities equal to that of the North Kings area are widespread in California. This contrasts with earlier findings suggesting that mountain lions were in low numbers in California. In 1922, a total of 600 mountain lions was estimated in the State. In 1976, the population was estimated at 2400 animals. In 1985 the California Department of Fish and Game reported 4,800 animals in the State, with an annual increase of about 8 percent.
With this wide disparity in density estimates, there is insufficient information to understand the relationship between mountain lions and the North Kings deer population. A study of mountain lions was undertaken and their movements in the range of the North Kings deer population in 1983.
This note reports a study to
(a) determine the daily and seasonal movements of mountain lions, in the central Sierra Nevada, with emphasis on the temporal correlarion with seasonal range use by deer;
(b) determine seasonal and annual home range sizes; and
(c) estimate mountain lion density.
The effort was not intended to be a major study of mountain lion ecology, only an aid to undershnding the role of the North Kings deer population to recover from its decline. Preliminary findings suggest that mountain lions could easily be limiting the North Kings deer herd.
