The persistence of the critically endangered Asiatic cheetah relies upon urgent connectivity protection: a landscape genetics perspective

Abstract

Decreasing genetic diversity, gene flow rates and population connectivity can increase inbreeding rates and extinction risks. Asiatic cheetah is a critically endangered mammal with large home range that suffered from extreme range reduction and population decline. Their population is now fragmented into two subpopulations. We used genetic markers to estimate genetic diversity, relatedness, minimum effective population size and gene flow, and to assess population structure. Putative corridors connecting subpopulations were inferred using connectivity models based on topography, land cover and human footprints resistance variables. Individual pairwise genetic relatedness was compared with resistance values obtained from these models and with Euclidean distances between samples to assess the most important factors shaping the current genetic structure. The estimated effective population size was extremely low (Ne = 11 to 17). Both Northern and Southern Subpopulations exhibited low genetic diversity and high relatedness. Several signatures of gene flow and movement of individuals between subpopulations were observed suggesting that inferred corridors potentially connecting subpopulations are functional. However, no traces of gene flow were observed for the latest generations, maybe due to a decrease of functional connectivity in recent years. The resistance model including all variables was best related to genetic relatedness, whereas population differentiation is mostly driven by isolation by distance. The very low estimated effective population size, decreased genetic diversity, and high relatedness of Asiatic cheetah suggests that population reinforcement, removing obstacles to connectivity and boosting prey population conservation in stepping stones are urgently needed to prevent the imminent extinction of iconic biodiversity.