Genetic Diversity of the Critically Endangered Nomascus hainanus Based on Non‐Invasive Sampling Microsatellite Analysis

ABSTRACT In the wild, non‐human primates may experience population declines resulting from low genetic diversity and inbreeding, while the scientific planning of ecological corridors can assist in population recovery and mitigate genetic diversity loss. The Hainan Gibbon ( Nomascus hainanus ) is the world's most endangered primate, endemic to Hainan Island in extreme southern China. Recent conservation efforts have successfully increased the number of Hainan Gibbon individuals to more than three times that of 20 years ago and six times that of 50 years ago. Updated information on population genetic diversity is urgently needed. In this study, we collected fresh fecal samples from 25 individuals in five family groups (A, B, C, D, and E) of Hainan Gibbon using a non‐invasive sampling method. We then evaluated and compared the variations in genetic diversity in Hainan Gibbon using 10 microsatellite loci. The sex identification experiment showed that the female‐to‐male ratio of the existing Hainan Gibbon population was 1:1.27. The population is still at a genetic bottleneck. Its dispersal mode is bisexual, and Hainan Gibbon tend to mate with individuals who have lower‐than‐average genetic relationships with themselves. The level of genetic diversity in family groups D and E was relatively low, while the genetic distance of D and E from family groups A, B, and C was relatively large. Currently, the Hainan Gibbon population exhibits no detectable genetic differentiation. With an effective population size of merely 13 individuals (95% confidence interval: 5.1–49.9), this critically endangered species remains at imminent risk of extinction. We suggest developing an ecological corridor between family groups A and E, which have a relatively large genetic distance.