Introduced from mainland China to the Bedfordshire countryside during the early twentieth century, these "vampire deer" -- so named for the long canine teeth (sometimes referred to as "tusks" or, incorrectly, "fangs") that males use during combat in the rut -- are now relatively widespread in East Anglia, particularly through the fen country, and the Home Counties where they thrive in arable farmland. It remains to be seen whether these deer will become invasive in the way the muntjac and sika deer have, but currently they appear to spread rather slowly, and where they live at low density have little impact on crops or forestry.
Water deer are arguably our least understood cervid and much of what we know today has been pieced together during studies of captive populations at Whipsnade Zoo, Woburn Abbey and Branféré Zoological Park in France, and through the meticulous studies of Arnold Cooke and Lynne Farrell in the Cambridgeshire fenland. Indeed, I am indebted to Dr Cooke for his assistance in the researching of this article; freely sharing his ideas, observations, and trailcam footage, while also providing me with several key papers and feedback on sections of this article. My thanks extend to Raymond Chaplin, who kindly donated some photos and shared with me home cinefilm of his captive water deer, some of which accompanies this article, as well as sharing his experience and unpublished research notes. I am also extremely grateful to Emma Mills at the ZSL Library for helping me with references, and to Michael Anker, Paul Childerley Adam Gage, Ben Harrower, David Hooton, and Jonathan Turnmore for being so generous with their knowledge and experience managing and surveying water deer in England. Several incredibly talented artists have been kind enough to spend their time trying to put the images in my head to paper based on my (at times, rather vague) descriptions, so I am hugely appreciative of Rachel Dubber, David Ziggy Greene and Willem van der Merwe. Thanks are also extended to Korean naturalist and wildlife artist Junha Kim for providing some valuable insight into the water deer situation, and etymology, in Korea, to Gayoung Kim for her help with Korean translations, and to Matthew Hargreaves of Antlers Cast and Present for providing insight into water deer coat structure. Finally, special thanks go to Sharon and Graham Scott for letting me camera trap on their farm, sharing observations of the wildlife that lives there, and for always being so hospitable.
What follows is a relatively detailed overview of Chinese water deer natural history – select a subject on the righthand side to learn more. Like everything on Wildlife Online, this profile is very much a piecemeal operation, with new information added as I come across it, and probably won't ever be "complete", but I hope it will suffice as a window into this under-studied mammal. A much more thorough treatment of the species, in particular their management, population dynamics and impact, which this article deliberately makes only a light touch upon, can be found in Arnold Cooke's authoritative and accessible book Muntjac and Water Deer, published by Pelagic Monographs in April 2019.
A summary of the more general aspects of the biology, ecology and behaviour of Britain's deer species can be found in the Deer Overview and certain aspects of the deer natural history that warrant more detailed discussion have been split from the main overview and placed into their own Q/A.
The Chinese water deer at a glance
Two subspecies are proposed within this monospecific genus: Chinese (inermis), found across China and South Korea, and Korean (argyropus), apparently restricted to South Korea. Though minor morphological differences exist, the phylogroups are distinguishable primarily through genetic analysis. The species is classified within Capreolinae -- the New World (telemetacarpal) deer -- and appears most closely related to roe deer (Capreolus sp.) and moose (Alces alces).
Size: Adults stand about 50 cm (~ 2 ft.) at shoulder and are 90 to 110 cm (3-3.6 ft.) long, with ears up to 11 cm (4 in.) tall and a stubby tail up to 6 cm (2 in.) long. They weigh 11-19 kgs (24-42 lbs), although most seem to average 12-15 kgs (26-33 lbs). Females tend to weigh more than males and some estates have observed consistent differences between deer living on marshes versus those in agricultural crops, the latter being slightly heavier.
Appearance: Often described as "teddy bear deer" owing to their thick winter coat, large round eyes and nose, and broad, highly mobile ears, water deer are sometimes confused with Roe and Muntjac, particularly at distance. They are muscular in build, with hind legs noticeably longer than the forelegs. Coat colour varies seasonally: a thick pale brown, buff, or grey-brown coat is typical in winter, replaced by a shorter red-brown coat in summer – moults occur in March/April and September/October, with the fur very loose during February. Fawns are born with a red-brown coat marked with rows of white spots, which fade at around six weeks. Males have prominent upper canine teeth (tusks) that begin growing during the first year. Neither sex carries antlers.
Distribution & Population: Native to China and Korea. Apparently fairly widespread in South Korea -- little known about their distribution in the North, although they do appear to be expanding into Russia, which perhaps implies an expanding population -- and originally widespread in China, but now appears largely restricted to the eastern Yangtze Basin in central eastern China. First imported to UK in 1873 by London Zoo and later introduced to Woburn Abbey in Bedfordshire (April 1896), from where the first known escapes occurred during the 1940s. Well established in wilds of Bedfordshire by the 1960s and 20 were culled on surrounding Woburn land in the early '70s. Escapes from multiple translocations of Woburn stock to other collections resulted in small transient populations elsewhere in England. Currently distributed discontinuously in Buckinghamshire, Bedfordshire, Cambridgeshire, Norfolk, and Suffolk – recent expansion into eastern parts of Oxfordshire in the west and southern Essex in east. Some small isolated populations may exist elsewhere which generate repeated sightings, including Lincolnshire and Dorset.
Overall, infilling within the core range is probably outpacing new colonisation beyond it in England. No recent survey data exist for Britain, but the latest published estimate (2025) puts the English population at around 18,000, with the true figure potentially substantially higher. Similarly, no recent data are available from China, where the last tentative estimate -- no more than 5,000 animals in 2011 -- remains the benchmark. Figures cited in the Korean media from authorities are strikingly high, with some suggesting perhaps as many as 700,000 animals in the South, though these are extrapolated from habitat density data rather than surveys. If accurate, such numbers cast doubt on the oft-cited claim that England holds around 10% of the global population; the true figure may be closer to 5%. England's population nonetheless retains conservation significance, apparently carrying genomes now lost in China.
Longevity/Mortality: Maximum longevity in the wild is unknown, while there are several reports of water deer surviving to 10-12 years in captivity, perhaps longer. Most wild animals probably survive no more than five years, and mortality is high among fawns – 40% die by four weeks old in some populations. Predation is generally not significant source of mortality, although foxes are probably the most significant predator of fawns – most fawns are stillborn or die from exposure/hypothermia. Increasing numbers appear to be killed on roads in England in line with increasing populations. In South Korea more than 200,000 are estimated to die on roads each year, while in China poaching remains a significant source of mortality. Various injuries are sustained by males during fights, which may subsequently fare badly in prolonged cold/wet/snowy weather. Bucks may occasionally kill one another during the rut.
Sexing: Males possess large, mobile, curved upper canines (tusks) typically measuring 4.5–5.6 cm (1.7-2.2 in.), occasionally up to 7.2 cm (2.8 in.), which protrude below the lower jaw and are erected during combat. They erupt at around six months, are clearly visible by one year, and reach full length by approximately two years, though they may continue to thicken. Female canines are present but usually vestigial, rarely exceeding 1 cm. Males are referred to as bucks, females as does, and young as fawns.
Activity: Active throughout the day and night, though with a marked crepuscular tendency – peaking in early morning and late evening, and often most active immediately after sunset. In my experience, they are also frequently encountered feeding around midday. Studies of captive individuals suggest roughly half of daytime activity is spent feeding, in bouts of around 20 minutes, interspersed with rest and rumination. Pregnant and suckling females may feed more extensively in early summer, while both sexes show increased activity during the December/January rut – bucks more so than does.
Habitat: Historically considered at wetland species, water deer are actually highly adaptable and can make a living in a range of habitats, from reedbed to arable farmland and even city parks. Water deer are an edge species, favouring transitions between habitat types -- woodland to grassland, reedbed to farmland -- with a general preference for tall, dense vegetation close to water. In their native Chinese and Korean range they frequent coastal reedbeds, salt marshes, river margins, and rice paddies, while studies across the Zhoushan Archipelago, Poyang Lake, and Yancheng Reserve consistently highlight their preference for tall grasses and reed communities, typically within half a kilometre of water. In Britain, they're primarily associated with wet carr and productive grassland, with nearly half the population range comprising fen and marshland. Across all regions, farmland plays an important supplementary role: deer regularly move out from cover into arable fields and pasture to feed, and in England they are also found on mixed farmland where reedbeds are absent, sometimes using cereal crops as a substitute for their native reed habitat. Seem significantly more urban in South Korea than elsewhere in their range.
Territory: Quite strongly hefted to an area, often spending their entire lives in only a handful of fields if conditions allow. In the literature, however, highly variable ranges have been reported, anywhere between 0.5 and 800 ha. Tracking data from China and Korea have generated larger areas than data from free-ranging captive animals in Britain. In the wild in England, ranges are probably 5-15 ha. Males may maintain territory -- which is marked with scent from glands on the front feet and below the eye, as well as urine and faeces -- year round, but the arrangement is flexible with environmental conditions and many bucks fail to maintain one. Females are sometimes territorial peri-partum.
Diet: Highly selective concentrate feeders, taking the tenderest growing tips, leaves and shoots rather than bulk vegetation. The diet is broadly composed of graminoids -- young grasses especially, but also rushes (Juncus) and sedges (Carex) -- forbs, broad-leaved species, and occasionally conifers and woody browse, with grazing appearing to outweigh browsing, at least in Britain. Agricultural crops may also be taken, including cereals, oilseed rape, carrots, potatoes, and peanuts, though there are also many reports of deer targeting weeds within fields rather than the crops themselves. They are notoriously difficult to supplement in captivity, with captive animals having refused hay even when starving.
Reproduction: Rut typically runs from late November to January, with peak activity in December, though bucks may begin closely following does from October. Activity is heavily weather-dependent, with cold conditions precipitating increased chasing and fighting among males. Pursuing bucks emit a high-pitched "whicker" or "chitter" when chasing rivals and a squeaking call when following does, which they may attempt to circle and hold on their territory. Water deer are the most prolific of Britain's deer: up to seven fawns may be born in May and June following a six to seven month gestation, though twins or triplets appear most common in England. Does often select open fields for both birth and this is also where fawns are likely to be found lying-up. Fawns weigh 600 g to 1 kg (1.3-2.2 lbs) at birth, can stand within an hour, begin eating solid vegetation within days, and are fully weaned by three months, remaining loosely associated with their mother until autumn. Both sexes are sexually mature by their first rut at around seven months, though first-winter bucks are less competitive at holding territory and many will not breed.
Behaviour and Sociality: Typically solitary outside of breeding season, although may aggregate to feed and rest during winter and spring when food scarce. Seems to enjoy lying out in the open in spring sunshine. Females sometimes form loose associations outside fawning season, but scatter if disturbed. Communicate with scent (esp. from pre-orbital glands) and sound: alarm barks (click below to listen); whickering/clicking/chittering (associated with aggression and frustration); squeak (breeding); gentle whistle (communication with fawn); contact bark (click below to listen); and distress call (click below to listen). During rut males parallel walk and 'dance' around each other striking with canines; does sometimes fight by rising on hind legs and 'scissor kicking' with front feet. Swims well from young age.
When alarmed, Chinese water deer vocalise with a fox-like bark that's often aimed at the source of the disturbance. - Credit: Marc Baldwin
A pair of Chinese water deer (Hydropotes inermis) calling at one another across a track on a Buckinghamshire farm. Contact barks are most often heard during the summer. - Credit: Marc Baldwin
When distressed a Chinese water deer will sometimes make a "whelp-like" call that sounds like a variation on the contact bark. This individual was caught in a drainage channel on a farm before being rescued by the landowner. - Credit: Sharon Scott
While chasing/fighting each other, bucks make a "chittering" noise, which we think they produce with their molars. The same noise is often made while pursuing a female. Here the chittering is followed by the buck squeaking at the doe. - Credit: Marc Baldwin
Threats: Water deer present a conservation conundrum: declining across parts of their native range due to habitat destruction, poaching, and use in traditional medicine, yet thriving in England, where the species is considered alien but not currently invasive or destructive. They are a mild agricultural pest at low to moderate densities -- particularly affecting cereal and brassica crops -- but do not appear to fray trees or cause significant forestry damage. At higher densities, both agricultural damage and road collision risk increase; the latter is already a serious problem in South Korea and appears to be growing in England. Poaching and coursing is common in England but does not seem to be detrimentally impacting populations. The species is bred for sport on game estates in England and widely shot by landowners across East Anglia and the Home Counties.
It is designated a protected species in China, and a Harmful Species in South Korea. Nothing is known about its conservation status in North Korea. It is an offence under Section 14 of the Wildlife and Countryside Act (1981) to release water deer into the wild in Britain.
Bibliography
Atlas of the Mammals of Great Britain & Northern Ireland - by Multiple Contributors
Pelagic Publishing
-- 2020
-- ISBN: 978-1784272043
Britain’s Mammals 2018: The Mammal Society’s Guide to their Population & Conservation Status - by Multiple Contributors
The Mammal Society
-- 2020
-- ISBN: 978-0993567339
Collins Field Guide: Mammals of Britain and Europe - by David MacDonald and Priscilla Barrett
HarperCollins Publishers
-- 1993
-- ISBN: 978-0002197793
Deer - by Raymond Chaplin
Blandford Press
-- 1977
-- ISBN: 978-0713707960
Deer - by John Fletcher
Reakton Books
-- 2014
-- ISBN: 978-1780230887
Deer - by Norma Chapman
Whittet Books
-- 1991
-- ISBN: 978-1873580356
Deer of Britain and Ireland: Their origins and distribution - by Peter Carne
Swan-Hill Press
-- 2000
-- ISBN: 978-1840370911
Deer of the World: Their Evolution, Behavior, and Ecology - by Valerius Geist
Stackpole Books
-- 1998
-- ISBN: 978-0811704960
Deer Watch: A Field Guide (Revised Edition) - by Richard Prior
Swan-Hill Press
-- 2007
-- ISBN: 978-1846890130
Deer: Law & Liabilities (2nd Edition) - by Charlie Parkes; John Thornley
Quiller
-- 2008
-- ISBN: 978-1846890475
Fauna Britannica - by Stefan Buczacki
Hamlyn Publishing
-- 2002
-- ISBN: 978-0600598671
From Wasp to Water Deer: A Rifleman’s journey through the countryside - by Martin Guy
Independently Published
-- 2020
-- ISBN: 979-8639971747
Living with Deer - by Richard Prior
Andre Deusch
-- 1965
-- ISBN: 978-0727401175
Mammals of the British Isles: Handbook, 4th Edition - by Stephen Harris and Derek Yalden (eds)
The Mammal Society
-- 2008
-- ISBN: 978-0906282656
The natural history "bible" covering all British mammals with detailed coverage of their biology, behaviour, ecology and taxonomy written by experts in the field and referenced to the primary literature.
Muntjac and Water Deer: Natural History, Environmental Impact and Management - by Arnold Cooke
Pelagic Publishing
-- 2019
-- ISBN: 978-1784271909
Nick Baker’s British Wildlife: A month by month guide - by Nick Baker
New Holland Publishers
-- 2003
-- ISBN: 978-1845171131
NIE Eco Guide 01: Korean Water Deer - by Baekjun Kim, Baegeun Lee & Youngjun Kim
National Institute of Ecology, Seocheon County
-- 2016
-- ISBN: 979-1186197523
In Korean. No English translation available.
The British Mammal Guide - by Steve Evans & Paul Wetton
Isabelline Films
-- 2015
-- ISBN: N/A
The Deer of Great Britain & Ireland: An account of their history, status and distribution - by Peter Carne
G. Kenneth Whitehead
-- 1964
-- ISBN: None
The Encyclopaedia of Mammals - by David MacDonald (ed.)
Brown Reference Group
-- 2006
-- ISBN: 978-0199206087
The Natural History of Deer - by Rory Putman
Christopher Helm
-- 1988
-- ISBN: 978-0801422836
The Naturalized Animals of Britain & Ireland - by Christopher Lever
New Holland Publishers Ltd.
-- 2009
-- ISBN: 978-1847734549
UK Mammals: Species Status & Population Trends - by The Tracking Mammals Partnership
JNCC/TMP
-- 2005
-- ISBN: 978-1861075680
Wild Animals of Britain & Europe - by Helga Hofmann
HarperCollins Publishers
-- 1995
-- ISBN: 978-0007627271