Monitoring status, habitat features and amphibian species richnessof Crested newt (Triturus cristatus superspecies) ponds at the edgeof the species range (Salzburg, Austria)

摘要

We studied the status of Crested newt (Triturus cristatus superspecies) ponds in the province of Salzburg during the years 2004 and 2005. Historical and current distribution data were collected and compared. In the end of 2004, 51 ponds with Crested newt records of which 39 still existed were known in Salzburg. In 2005 we carried out a monitoring of these ponds using a combination of three survey methods. Presence or absence of adult and larval Crested newts and the number of syntopic amphibian species were recorded. Detection probabilities and the effects of seven characteristic pond features on pond occupancy were calculated for adult and larval newts separately. We observed a strong decline of ponds occupied by Crested newts with presence of adults in 22 and presence of larvae in 16 surveyed ponds, respectively. Detection probabilities imply that we detected all ponds occupied by adults and larvae. Key habitat features for Crested newt presence are low degree of shading for adults and larvae as well as a high density of submerged vegetation for larvae. Pond size and depth are not significant. Furthermore we recorded a significantly higher number of amphibian species in ponds occupied by Crested newts. Our results might aid in the implementation of sustainable measures for a conservation of these critically endangered species in the province of Salzburg.