Climate change and peripheral populations: predictions for a relict Mediterranean viper

Abstract

Ecological niche-based models were developed in peripheral populations of Vipera latastei North Africa to: 1) identify environmental factors related to species occurrence; 2) identify present suitable areas; 3) estimate future areas according to forecasted scenarios of climate change; and 4) quantify habitat suitability changes between present and future climatic scenarios. Field observations were combined with environmental factors to derive an ensemble of predictions of species occurrence. The resulting models were projected to the future North African environmental scenarios. Species occurrence was most related to precipitation variation. Present suitable habitats were fragmented and ranged from coastal to mountain habitats, and the overall fragmented range suggests a relict distribution from wider past ranges. Future projections suggest a progressive decrease in suitable areas. The relationship with precipitation supports the current unsuitability of most North Africa for the species and predicts future increased extinction risk. Monitoring of population trends and full protection of mountain forests are key-targets for long-term conservation of African populations of this viper. Predicted trends may give indications about other peripheral populations of Palearctic vertebrates in North Africa which should be assessed in detail.