THE STATUS OF THE CALIFORNIA TIGER SALAMANDER (AMBYSTOMA CALIFORNIENSE) AT LAGUNITA - A 50-YEAR UPDATE

We review the history of the California tiger salamander (Ambystoma ca liforniense) population at Lagunita, a 114-year old reservoir at Stanf ord University, Santa Clara County, California. The animals apparently colonized the reservoir during the late 19th century, reached a popul ation peak during the first half of the 20th century, and have decline d since to near extinction. The apparent causes of this decline are ha bitat loss due to urbanization, adult salamander mortality from automo biles, loss of larvae during the annual reservoir drainage, and possib ly predation by transient fish populations. Recommendations to preserv e the population and to allow its size to increase include: (1) constr uction of a drift fence and tunnel system to divert migrating adults a nd juveniles underneath the highway, (2) maintenance of water levels t hrough mid-summer to allow most larvae to complete metamorphosis, and (3) excavation of sumps in the lake bed to entrap larvae and keep them from being swept down the lake drain.