Trophic Relationships in Larval California Newts (Taricha torosa)

Abstract. The larval stage of the California newt (Taricha torosa) has been little studied despite the presence and abundance of the species throughout much of California. During the 2017–2018 time period, the diet and life history characteristics of this cohort of stream-dwelling newt larvae were examined, using gut contents and stable isotopes, in order to better understand the ecological niche and trophic relationships of the life stage. Our results suggest that the newt larvae consume Chironomidae as a major part of their diet and that this reliance decreases as the larvae age. Newt larvae also feed more widely and abundantly as they age. The isotopic data suggest that as larvae get larger, they alter their diet but that the relationships to both carbon source (δC) and trophic level (δN) are complex.