Are Crotaline Population Survival Estimates Representative of Viper Populations as a Whole?

Maritz, Bryan

Maritz, Robin A.

bryanmaritz@gmail.com

Department of Biodiversity and Conservation Biology University of the Western Cape

Private Bag X17

Bellville, South Africa

Glaudas, Xavier

Alexander, Graham J.

School of Animal, Plant and Environmental Sciences University of the Witwatersrand Johannesburg

PO Wits, South Africa

Estimates of annual survival rates can inform understanding of gene flow, trophic ecology, population ecology, and the conservation and management of organisms. Among vipers (family Viperidae) numerous studies have estimated annual survival rates for populations of pitvipers (subfamily Crotalinae). These estimates, together with a small number of estimates from European viperine species (subfamily Viperinae), dominate our understanding of viper life history. However, it remains unclear how representative these estimates are for other vipers. Here, we draw on a 7-year radio-telemetry dataset encompassing more than 120 individuals, and use a known-fate model to estimate annual survival for a population of African viperine, the Puff Adder (Bitis arietans). Our findings, along with a review of other estimates of viperine survival, suggest that African viperines may experience substantially lower survival rates than crotalines and non-African viperines. We discuss the major drivers of mortality in our study population and close by examining the implications of our findings for viperid life-history theory.