Survival and degree of transience in the fire salamander (Salamandra salamandra) population, the eight-year study

Abstract

We analyzed the survival, transience, and population dynamics of the fire salamander (Salamandra salamandra) in an eight-year capture-recapture study using the Cormack-Jolly-Seber model. This apparently healthy population from Central Bohemia does not currently face any serious anthropogenic threats, and our demographic results could therefore be used to assess the extent of negative effects for other populations facing more serious stressors. We focused on the following parameters: lifespan, survival, recapture estimate, population size and abundance trends, degree of transience and site fidelity vs. tendency to disperse. Depending on the year, mean population size estimates range from 146 to 176 for resident adult males and from 109 to 146 for resident adult females. Males are more likely to be on the surface than females. The mean annual apparent survival probability is 0.80 and 0.70 for males and females, respectively (adult residents and transients combined). The net survival probability is 0.91 and 0.90 for adult resident males and females, respectively. The mean life expectancy after reaching sexual maturity (at three years of age) is 10.6 years for resident males and 9.7 years for resident females in our lowland population. The mean level of transience is 0.13 for males and 0.19 for females. The transient behavior of females is a consequence of their spring migration to the breeding stream and the transient behavior of males reflects their autumn search for females. 89% of the males and 85% of the females moved less than 50 m in one year and 52% of the males and 42% of the females moved less than 15 m. There were many individuals of both sexes who remained in the same, or almost the same place, or returned to exactly the same place, even after 4 years.