Among-population variation in monthly and annual survival of the Baja California Tree Frog, Pseudacris hypochondriaca curta, in desert oases of Baja California Sur, Mexico

Abstract

Survival is an important component of the demography of an animal. We estimated monthly and annual survival probabilities of three populations of the Baja California Treefrog (Pseudacris hypochondriaca curta) inhabiting desert oases of Baja California Sur, Mexico. We used data from a two-year mark recapture study to estimate survival. Recapture probabilities varied widely among months and there was no clear temporal pattern underlying the fluctuations. Annual survival was 27 and 29% for two populations and 1% for the third population. This implies that the populations, particularly the third one, can persist only if there is steady and high recruitment. With annual survival as low as 1–29%, a lack of recruitment could quickly cause local extinction. Because immigration seems unlikely in these populations due to their isolation from other breeding populations, recruits must be produced locally. Non-native fish, crayfish, and frogs that prey on tadpoles may therefore be a threat for the persistence of the populations.