"Chinese water deer" or just "water deer"?
I regularly observe water deer (Hydropotes inermis) on the marshes near to where I live in Norfolk England. These fantastic looking animals (sometimes with vampire-like fangs) were accidentally introduced following the escape of captive individuals in the early 1940s from Woburn Abbey, Bedfordshire (UK animals now make up over 40% of the global population). The first record of this species in Norfolk was a single individual recorded at Hickling Broad in 1968, but they have subsequently spread to include most of the 'Norfolk Broads' as well as the north Norfolk coast. Locally people call these animals 'Chinese Water Deer' but the native distribution includes populations in China and in the Korean peninsula where experts often regard them as separate sub-species - the Chinese water deer (Hydropotes inermis inermis) and the Korean water deer (Hydropotes inermis argyropus). This led me to wonder whether observations in the UK should be labelled only as "water deer" Hydropotes inermis or whether they could justifiably be narrowed down to "Chinese water deer" Hydropotes inermis inermis?
An answer to this question has recently been provided by Putman et al. (2021) [https://academic.oup.com/zoolinnean/article-abstract/191/4/1181/5875588?redirectedFrom=fulltext] based on a genetic analysis of animals in China, Korea, France and the UK (as well as captive herds). This study suggested that water deer in Great Britain are not directly descended from any population remaining in China at present, and that the source population of British deer is likely to be extinct (probably individuals sourced from around Shanghai, where they no longer occur). Therefore, it is probably safest to simply call them "water deer" Hydropotes inermis.
