Habitat-use model for the New Zealand endemic frog Leiopelma hochstetteri

Abstract

Leiopelma hochstetteri is the most widespread and abundant endemic frog species in New Zealand, although it now survives only in spatially fragmented populations throughout the North Island of New Zealand and the Great Barrier Island of northeastern New Zealand. The species is known to occur in wet areas adjacent to shaded streams in forested catchments; however, no quan- titative ecological data exist to enable characterisation of its habitat. In the present study, novel data on the current distribution and habitat requirements of this species are reported for 1 population in the Waitakere Ranges, northwestern New Zealand, which is considered as a conservation manage- ment unit for the species. Frogs were found within most streams surveyed (68.2%). Statistical model- ling demonstrates that frogs most likely occur in small, erosive streams with coarse substrates and cold waters, surrounded by mature or undisturbed riparian vegetation. Anthropogenic activities such as clearing or logging are identified as threats to this frog species.