The Herpetological Journal

pp.161-165

Authors: Xavier Santos And Gustavo A. Llorente

Abstract: The Ebro Delta is a wetland area partially covered by rice fields.The viperine snake Natrix maura, is a common colubrid snake in this ecosystem. Males delayed feeding activity by one month, and foraged for a shorter time, compared to females. Diet consisted mainly of fish and frogs, although size-related and sexual differences were found: immature snakes had a more diverse diet than adults, and adult females ate more frogs than adult males. Males captured larger numbers of smaller fish than females. Like other water snakes, large viperine snakes avoid small prey. The biomass ingested is higher in large females, providing supplementary resources for reproduction. These dietary differences may be related to the ecological needs of each category of snakes and reflect the influence of the rice cycle on diet dynamics.