Biogeography and conservation of viperids from North-West Africa: An application of ecological niche-based models and GIS

North-West Africa is an outstanding region to study biogeographic patterns in biodiversity distribution. This study identifies biogeographic affinities and areas of probable occurrence for seven viperid snakes through the combination of high resolution presence data and environmental factors. Vipers exhibited distinct biogeographical affinities: Bitis arietans was mostly found along savannahs, Echis leucogaster along the Sahel/savannahs, Cerastes cerastes and C. vipera throughout most desertic areas, Daboia mauritanica in coastal and hilly regions and Vipera latastei and V. monticola in almost only mountains. Suitable habitats were predicted for B. arietans in southern Senegal and Mali, and coastal southern Morocco, for E. leucogaster in southern Mauritania, Senegal, Mali, and fragmented habitats in Saharan mountains and south-western Morocco, for C. cerastes from the Atlantic coast to northern Algeria, for C. vipera in the central region, for D. mauritanica in northern-western Morocco and northern Algeria, for V. latastei in the Rif, Middle Atlas and coastal Morocco, and for V. monticola in the High Atlas. In potential sympatric areas, competition is probably limiting distribution, resulting in parapatric ranges. Northern Saharan populations of B. arietans and E. leucogaster are isolated. Saharan mountains and coastal south-western Morocco constitute isolated suitable areas for sub-Saharan relicts.

► The distribution of seven viperid snakes in North-West Africa is assessed.
► Biogeographical affinities of vipers and areas of probable occurrence are identified.
► Some Northern Sahara viper populations are isolated.
► South-western Morocco is a region targeted for conservation.
► Saharan mountains may constitute refugia under climate change scenarios.