Conservation genetics of native and European-introduced Chinese water deer (Hydropotes inermis)

Sufficient genetic variation is vital for the long-term survival of a population. The adaptive potential and reproductive fitness of a population is generally enhanced by greater levels of genetic diversity, while loss of genetic variation in small populations may increase extinction risk due to disease susceptibility and decreased reproductive fitness. Determining levels of genetic diversity in threatened species can, therefore, help inform conservation strategies. The Chinese water deer (Hydropotes inermis) is classified as Vulnerable in its native range on the IUCN Red List, and populations in Korea and mainland China have declined drastically in recent years. However, the species was introduced to Europe about a century ago and populations there now make up over 40% of global numbers. To infer the population genetic structure and genetic diversity of Chinese water deer both in their native China and in populations introduced to the UK and France, variation in mitochondrial DNA was investigated for over 100 individuals (92 cytochrome b and 106 control region sequences). Our results reveal lower levels of genetic diversity in the British populations, differentiation between native and introduced populations, and that the source population of British deer is likely to be extinct. Recommendations are made for the conservation of populations.