Effects of temperature and precipitation on breeding migrations of amphibian species in southeastern Norway

Abstract

To reveal the effects of climate, a generalized linear mixedmodelwas used to explore the variation in onset of spawning migration for the two newt species T. cristatus and L. vulgaris in southernNorway.Amphibians are highly influenced by the physical environment, such as temperature and rainfall.Thefirst migrating newts were observed subsequently to the three first consecutive days with mean temperature close toor above4∘C. Further,migration of L. vulgaris was facilitated at lower temperatures compared to T. cristatus, but the migration was dependent on higher precipitation levels. Northern populations of T. cristatus and L. vulgaris may already benefit from a warmer climate due to increased recruitment and juvenile survival. However, an offset in the migration phenology due to climate change might further alter the recruitment and survival rates with either positive or negative outcome.Thus, variations in migration phenology for newts due to climate changemay have implications for management and protection status inmany systems. In a general context, we should increase emphasis on protecting newts and support increased populations and distribution.