MODIFIED INTERACTIONS BETWEEN SALAMANDER LIFE STAGES CAUSED BY WILDFIRE-INDUCED SEDIMENTATION

A 1993 wildfire and subsequent landslides modified many streams in the Santa Monica Mountains of southern California (USA). Prior to the fir e at Cold Creek Canyon, adult California newts (Taricha torosa) freque ntly preyed on conspecific eggs and larvae. Post-fire landslides incre ased the number of stream pools containing terrestrial earthworms. Ear thworms were more common in adult newt diets after the fire, and consp ecifics were absent. More earthworms and fewer conspecifics were prese nt in the stomachs of adult newts in streams at burned sites than at u nburned sites. In laboratory experiments, newt larvae used refuges sig nificantly less in the presence of combined chemical cues from both ne wt adults and earthworms as compared to adult-newt cues alone. These d ata suggest that cannibalism is reduced in the presence of increased a lternative prey items and that larvae can detect this reduced predatio n risk.