Siberian tiger's recent population bottleneck in the Russian Far East revealed by microsatellite markers

Abstract

Because size reduced, or bottlenecked, populations are more prone to adverse events, the detection of genetic bottleneck signatures in wildlife species is highly relevant for conservation. Here we applied 11 microsatellite markers to the endangered Siberian tiger ( Panthera tigris altaica) using tissue and blood samples of animals from the Primorsky region of the Russian Far East. Excess heterozygosity and mode shift in allele frequencies tests were positive, while the M-ratio test was negative, indicating the likelihood of a contemporary rather than a historical population bottleneck. The recent genetic population bottleneck could be attributed to the well-documented demographic collapse of the Siberian tiger population in the 1940s, when population size hit bottom with 20–30 surviving animals. The mean effective population size N e was 14 Siberian tigers (CI 95: 12–25 animals), and the effective population size/census size ratio ( N e / N ratio) was 0.028. This is the first molecular evidence of a recent Siberian tiger population bottleneck, which is of great interest for further conservation and management plans of the highly endangered largest felid species, while the worryingly low effective population size challenges the optimism for the recovery of the huge Siberian cat.