PARENT SESSION
Oral Session # 58: Rare, Threatened, and Endangered Species III: Reptiles and Amphibians.
Presiding: K Beard
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 202.

Demographic contributions to population growth and decline in a salamander.

Schmidt, Benedikt ^{*,1, 2}, Feldmann, Reiner³, Schaub, Michael⁴, ¹ University of Zurich, Zurich, Switzerland² KARCH, Bern, Switzerland³ Pfarrer-Wiggen-Strasse, Menden, Germany⁴ University of Bern, Bern, Switzerland

ABSTRACT- Amphibian populations are declining worldwide. Efficient conservation action requires that we understand which stage(s) in the complex life cycle of amphibians contribute most to population growth (or decline) and which stage(s) are most sensitive to environmental change. Here, we study the demography of a stationary and a declining population of the salamander Salamandra salamandra, and assess whether an observed decline in one population is due to a change in recruitment or adult survival. The two populations were studied for c. 20 years and all salamanders were known individually. We analyze this data set using a multistate capture-mark-recapture model with an unobservable state. Our analysis shows constant adult survival and variable recruitment in the stationary population and declining adult survival and constant recruitment in the declining population. This suggests that the decline is due to a change in adult survival, which was probably caused by a change in forest management. The common paradigm in amphibian population ecology is that population growth is determined at the larval stage. Our results show that this may not always be the case.

Key words: salamander , decline , amphibian, demography