Effects of population density on spatial genetic structure in a subterranean rodent, the Plateau Zokor (<i>Eospalax baileyi</i>)

Abstract Sex and population density, among other factors, affect individual dispersal distances, therefore affecting the spatial genetic structure (SGS) of the species. However, the dispersal pattern of subterranean mammals and its influence on SGS is less known. In this study, we investigate the influence of sex and population density on the dispersal distance of individuals and the SGS of subterranean rodents using Plateau Zokor (Eospalax baileyi) as a model. We genotyped adult Plateau Zokor populations at varying densities (low, medium, and high) using 12 microsatellite loci during the pre-overwintering period. Based on genetic diversity estimates, we found evidence of male-biased dispersal in 6 zokor populations. Our analysis of individual-based spatial autocorrelation showed no SGS in either sex in populations at low and medium density. In contrast, at high density, populations exhibited positive SGS at 55 m in females, but positive SGS at 110 m was observed in males. Our data indicate that females and males at higher population densities had shorter dispersal distances, leading to the formation of SGS within local zokor populations. Our study contributes to understanding how population density influences dispersal behavior and the resulting genetic structure of subterranean species.