Tracking Mountain Lions in the Santa Monica Mountains National Recreation Area

This study monitors the distribution and movement of mountain lions in the Santa Monica Mountains, Simi Hills, and Santa Susana Mountains. In March 2002, remote cameras were placed throughout the mountain range to assess whether such large carnivores still existed within the Santa Monica Mountains. Proof came in April when the first photo of a mountain lion was taken. Capture efforts began several weeks later, and in July 2002, the first mountain lion was radio-collared. Weighing more than 140 pounds, the adult male lion (P1) has logged more than 2,500 locations in the two years since his initial capture. Preliminary calculations place P1's home range at 430 square kilometers, spanning roughly the entire Santa Monica Mountains.

Three additional lions have been radio-collared since then including two females: one limited to the central Santa Monica Mountains (P2) and the other to the eastern Santa Susana Mountains (P4). A juvenile male (P3) was captured and radio-collared north of U.S. Highway 101 in the Simi Hills, an area still undeveloped and critical in connecting the Santa Monica Mountains to the Santa Susana Mountains. Although the preliminary home range size is equivalent to P1 (approximately 436 square kilometers), because the Simi Hills do not contain sufficient habitat area for a single male lion's home range requirements, P3 has extended his range by moving across a major freeway on several occasions at an underpass to and from the much larger Santa Susana Mountains. The locating and tracking of additional lions in this highly fragmented region continues.