Habitat features affecting the small-scale distribution and longitudinal migration patterns of Calotriton asper in a Pre-Pyrenean population

Abstract

AbstractThe longitudinal movements and abiotic factors that determine the distribution of Pyrenean mountain newts (males, females, amplexus and metamorphic newts) were examined in a 1500 meters segment of a Pre-Pyrenean stream. Migration of adult newts was studied by means of capture-recapture techniques in the course of one year. Our results indicate that the mean distance the newts migrated per year was less than 50 meters and the population could be considered sedentary. No significant differences in longitudinal movement patterns between the sexes were observed, and movement patterns were more or less constant over time. Habitat variables determining newt abundance was estimated by means of a GLM. Our results indicate that the number of refugia (wood debris, stones and fissures) determines the distribution of newts. Larval abundance was correlated with stream-bed structure.