Water Deer Interaction with Humans - Response to Disturbance

Water deer are behaviourally similar to hares in that, when faced with danger, they will duck low in cover and remain quiet and motionless, before erupting away at the last minute. John Heathcote, who manages the Claxton Manor estate in Norfolk, told me that water deer are the only species he knows that can be disturbed standing on the edge of a copse and flee away from the trees rather than into them, something I have also observed. On two occasions, both with does (females), I observed a deer to "pseudo-graze" -- where the deer spots something suspicious and puts its head down "pretending" to feed, an action that might make a predator think it's not been spotted and therefore move, but while keeping their eyes fixed on the source -- which is a behaviour I have hitherto only come across in roe deer (Capreolus capreolus). In common with other deer, although much less conspicuous owing to its size and lack of rump markings, a fleeing water deer will sometimes hold its tail upright (known as "tail flagging"). They will often also kick out with their hind feet in what might be an anti-predator behaviour (i.e., kicking sharp hooves at whatever's in pursuit). Tail flagging and rear-kicking may occur simultaneously and are behaviours I have observed both in adults and in fawns at four or five weeks old.

Humans appear to be perceived as a threat in most instances, and this can make water deer very difficult to approach. In their 1981 Nature Conservancy Council report, Arnold Cooke and Lynne Farrell described how, during the autumn of 1976, they attempted to assess how close the deer at Woodwalton Fen in Cambridgeshire would tolerate being approached. Across 22 encounters, the mean flight distance (FID) was 36 m (118 ft.) -- i.e., the observer could get to 36 m away before the deer ran away -- although the range was from 8 m (26 ft.) to 79 m (260 ft.) according to age and the habitat in which they were approached. Younger deer tended to be less flighty than adults, and those in the reserve could often be approached more closely than those in the surrounding arable fields. Reflecting on this in June 2025, Arnold told me: "I remember it was quite difficult to get a deer in a situation where it could be recorded properly, i.e. in the open where I could approach it in full view without it dashing off immediately or even before I'd seen it.".

The overall timid nature of water deer is evident even in captivity, unless they've been hand-reared, which can make them strongly imprinted on their human "parent". (At Whipsnade, I've seen fawns come when called, and saw one four-week-old fawn scream and throw itself at a fence when its keeper left the enclosure.) At Whipsnade Zoo, where the deer see people throughout the year, my experience has been that they remain relatively skittish and can be difficult to observe at close quarters without the cover of a vehicle, although they're still easier to approach than wild individuals. Richard Champion demonstrated this empirically during his B.Sc. thesis at Whipsnade in 1996, finding that water deer using public areas of the zoo adapted to human disturbance by significantly reducing their average flight distance (i.e., the minimum distance at which they fled). Deer utilising public parts of the complex could be approached to within 17.5 metres (56 ft.), on average, while those using the private (off-show) areas fled when an observer came to within 35 m (115 ft.). There was considerable individual variation in the distance run when disturbed, 'public deer' fleeing between two and 110 m (6.5-361 ft.), while those off-show moved between four and 120 m (13-400 ft.). Perhaps more interestingly, Champion observed that flight distances were longer (i.e., the deer were more skittish) during the morning than the evening in public areas, while those off-show were much more consistent throughout the day. Females were generally more sensitive to disturbance than males.

Champion's findings were broadly replicated by Xin-Xin Tian in his M.Sc. studies at East China Normal University, during which he compared the response to human approach among free-ranging captive deer kept at the Songjiang Punan forest park to that of wild deer living on the Yancheng Nature Reserve in Jiangsu Province. Vigilance/alert behaviour consisted of five elements: listening, scanning, staring (which may or may not be accompanied by neck stretching), walking or running away, and barking. At no point did Tian observe water deer acting aggressively towards a potential threat. Songjiang deer stopped what they were doing and stared at an intruder at 23 m (75 ft.), on average, and ran away when the person got to within about 19 m (62 ft.). The longest recorded flight distance at Songjiang was 150 m (492 ft.), while that at Yancheng was nearly 180 m (590 ft.), suggesting wild deer were significantly more skittish than free-range captive animals. Tian concluded that, as a direct approach did not alter the flight initiation distance for semi-captive water deer, humans were perceived as a non-lethal predator. He also noted that an anti-predator response is developed early (at around a week old) and that the deer appeared to risk assess prior to fleeing, running away sooner in open habitat than woodland and their distance varying according to their previous experience with humans, size of the area, population density, and the presence of fences.

My experience has been that there's considerable individual variation in disturbance response, both in adults and fawns. Unlike in herding species such as red (Cervus elaphus) or fallow (Dama dama), where alarm responses alert the whole herd, it is quite common for one water deer to bark and flee (or stand and bark) while other individuals feed nearby without showing any obvious disturbance (see: Vocalisation/Calls). Equally, on two occasions I have witnessed water deer does respond to the barking of a Reeves' muntjac (Muntiacus reevesi); once just looking in the direction and once running at speed towards the source of the disturbance (I believe this was a dam with a fawn in the area). On several occasions I have seen a doe with a fawn at foot bark and flee in one direction, while her fawn fled in a different direction before lying down a few metres away. In one case, I was watching a doe with a four- or five-week-old fawn at foot feeding shortly after sunrise for about 10 minutes before she spotted me. After a minute or so of staring and neck stretching she barked and fled; her bark caused the fawn to immediately drop down into the grass and sit tight. More recently, biologists at Shanghai's East China Normal University collected data on how these anti-predator behaviours develop in fawns. Between June and October 2023, the researchers, led by Xiaorong and Min Chen, observed how 30 ear-tagged water deer fawns kept in a 0.5 ha (1.2 acre) enclosure in Huaxia Park, composed of broadleaf woodland and grassland, responded to their approach, the aim being to understand at what age vigilance behaviours developed. In their 2025 paper to Behavioural Processes, the researchers documented the five main vigilance behaviours we recognise in adults in their subjects, categorising them as:

Flight - The fawn turns and flees from the observer's approach.
Stare - The fawn stands or lies and looks in the direction of the observer for a varying period.
Stretch neck - The fawn bobs its head up and down, sometimes also side to side, while staring fixedly in the direction of the disturbance.
Vigilant paw - The fawn lifts the foreleg and suddenly strikes the ground with the hoof one or more times.
Roar - The fawn vocalises, making a short, repetitive sound of 'ER---". This is presumably intended to alert their mother.

The most frequently observed behaviours were staring and fleeing, recorded 942 and 915 times, respectively, and together these were clearly the dominant vigilant strategy. The FID ranged from 0 to 10.6 m (35 ft.), with a mean of 2.4 m (8 ft.) and, broadly speaking, older fawns (9-18 weeks) had a lower FIDs than younger ones (1-8 weeks) - those less than a week old did not flee as is expected in newborns. The roar/vocalisation was only heard twice, both times in fawns less than three weeks old, while neck stretching and vigilant pawing developed at around 10 weeks old. Indeed, as the fawns grew older their vigilance behaviour became more complex, with just shy of 41% of behaviours explained by the fawn's age, while the presence of another deer, the direction of the observer's approach, and the presence of shelter each accounted for no more than 5% of the responses. In other words, as fawns aged they incorporated different combinations of behaviours and older fawns tended to exhibit more behaviours during any given approach (i.e., had more decision-making chains), presumably as the fawns' experience of risk assessment increased. Interestingly, unlike some other studies that have found animals in general fear human eye contact, the researchers found no significant influence of observer eye contact on the fawns' decisions or behaviour, noting that "Chinese water deer perceived threat sources more holistically, sometimes fleeing without seeing the human's eyes".

I know of no equivalent data on water deer behavioural response to humans in Korea, but they do seem more likely to live in and around human habitation and I have seen YouTube and social media footage of what appear to be deer even in towns or cities in the south. In a 2011 paper to Landscape Ecology and Engineering, however, Baek-Jun Kim and colleagues reported that water deer were significantly less common in metropolitan areas with populations in excess of one million (67% of samples) than in rural areas (83% of samples). It is nonetheless my opinion that water deer have adapted to human presence to a greater degree in South Korea than elsewhere.