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Université de Fribourg

Mark-recapture Estimates of Survival in Populations of the Asp Viper, Vipera aspis aspis

Flatt, Thomas ; Dummermuth, Stefan ; Anholt, Bradley R.

In: Journal of Herpetology, 1997, vol. 31, no. 4, p. 558-564

We estimated th eannual survivorship of two populations of the asp viper, Vipera aspis aspis, by recapturing known dult individuals in the field over six and nine years respectively. The snakes at the two study sites in th eJura mountains of northwestern Switzerland were active between mid-March and mid-October. Vispera a. aspis is easily captured by hand, has individually recognizable marks and...

Université de Fribourg

Winter weather affects asp viper Vipera aspis population dynamics through susceptible juveniles

Altwegg, Res ; Dummermuth, Stefan ; Anholt, Bradley R. ; Flatt, Thomas

In: Oikos, 2005, vol. 110 (1), p. 55

Detailed studies on mammals and birds have shown that the effects of climate variation on population dynamics often depend on population composition, because weather affects different subsets of a population differently. It is presently unknown whether this is also true for ectothermic animals such as reptiles. Here we show such an interaction between weather and demography for an ectothermic...