Fig. 1

Basic information about wild sika deer. a The study area of wild sika deer in China, namely, Tiebu Nature Reserve (Sichuan population) and Hunchun Nature Reserve (Northeast China population). The photo shows the differences in living environments between the two populations. b Phylogenetic relationship of sika deer mtDNA control region haplotypes reconstructed on the basis of the maximum likelihood algorithm with C. elaphus as the outgroup. The bubble plot represents the frequency with which haplotypes appear in the group, Northeast China population (red), Sichuan population (green), South China population (yellow), Figure is modified from Liu et al. [45]. c Minimum spanning network for haplotypes. The circle size is proportional to the number of individuals bearing that haplotype. Nucleotide transitions and transversions are indicated by dashes respectively (Only one transition between haplotypes is not marked), Figure is modified from Liu et al. [45]