TRENDS IN CALIFORNIA MOUNTAIN LION POPULATIONS

The status of the California mountain lion (Felis concolor californica May) population has been controversial and central to disputes regard ing its management. Track survey methods and transects were developed during the 1980s to provide the only standard estimate of mountain lio n population trends in California. In 1992, I repeated the 1986 statew ide survey for mountain lion track sets, in which a track se is any co ntinuous trail of tracks made by the same animal. Track set density in creased 313% in the mountains Df southern California, but they decreas ed 52% in northern California, and 61% in areas where timber was remov ed since 1986. Most of the areas preferred by resident mountain lions in 1986 were avoided in 1992 after they were clearcut. Whereas residen ts preferred unharvested and non-forest areas in 1992, track set densi ties of deer were the same with or without timber loss. Mountain lion track set density might have decreased due to degradation of habitat q uality other than prey availability, or it might have decreased as par t of a natural population cycle, which is common among species of Carn ivora. When this decrease was added to the changes observed at three s ites monitored since 1980, the pattern resembled nearly one complete c ycle. Plans for management and research of mountain lions should inclu de the effects of habitat loss and natural population dynamics.