Delineation of terrestrial reserves for amphibians: Post-breeding migrations of Italian crested newts (Triturus c. carnifex) at high altitude

Little is known about the terrestrial phase of high-altitude populations of European amphibians, in spite of potentially important implications for conservation and management. We followed 51 adult Italian crested newts (Triturus carnifex) that emigrated from an ephemeral lake (Lake Ameisensee, 1282 m a.s.l., Northern Calcareous Alps, Austria) with radio-tracking. Transmitters were inserted into each newt’s stomach and we collected data until it did not relocate for more than 1 week or until the transmitter was regurgitated. Most newts migrated in a north-westerly direction towards an old growth spruce forest. Subterranean shelters, mostly 5–80 cm deep burrows of small mammals located 13–293 m from the lake, were reached in between 4 h and 7.8 days. Twenty percent of T. carnifex shared their refuges with other congeneric species. Females migrated significantly further (median distance 168 m) than males (median 53 m). We propose a terrestrial core reserve extending 100 m from the furthermost terrestrial refuges of newts found with radio-tracking linked with patches of old-growth forest. This terrestrial reserve is substantially larger than has been suggested as sufficient in the recent literature