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 californiense) population at Lagunita, a 114-year old reservoir at Stanford University, Santa Clara County, California. The animals apparently colonized the reservoir during the late 19th century, reached a population peak during the first half of the 20th century, and have declined since to near extinction. The apparent causes of this decline are habitat loss due to urbanization, adult salamander mortality from automobiles, loss of larvae during the annual reservoir drainage, and possibly predation by transient fish populations. Recommendations to preserve the population and to allow its size to increase include: (1) construction of a drift fence and tunnel system to divert migrating adults and juveniles underneath the highway, (2) maintenance of water levels through 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.