Water Deer Behaviour - Aggression & Submission
Aggression
While many of the behaviours that we associate with aggression in deer are seen in fawns during bouts of play (especially social play), true aggression seems to be restricted to sexually mature individuals, adults in particular. Males tend to be more aggressive towards one another than they are to females, or than females are to either sex. Male aggression tends to be high from late autumn through until mid-spring, with peak antagonism during the winter rut. Indeed, writing in his 1950 Deer of the World, Kenneth Whitehead noted:
“The bucks seem to fight quite as much during the spring as during the rut.”
Writing in 2001, Arnold Cooke and Lynne Farrell presented data on the relative frequency of whickering and silent chases at Woodwalton Fen reserve in Cambridgeshire and on surrounding farmland through the winter, from October to March - March was the second highest after December. I have observed similar behaviour in the wild, with hard chases, dancing and whickering in March and early April, and on the Claxton Estate in Norfolk, John Heathcote has seen chasing during the spring and found dead deer (mostly bucks, but also a few does) in April with puncture marks to their necks that appear to match the inter-canine distance of the species, suggesting serious aggression persists outside of the rut. Likewise, Paul Childerley has reported violent chases between bucks in March, the subordinates sometimes receiving deep lacerations to their rump. I cannot think of any explanation for such intense aggression persisting so late in the season, given that androgen levels appear to drop sharply in January and remain low until the following autumn.
Female-female aggression much less common and tends to be concentrated during late pregnancy and early fawn rearing (i.e., April-June), although Sharon Scott has captured what appears to have been an aggressive encounter, including some intense chasing, between does in Buckinghamshire during late September 2023.
Aggression is invariably directed at other water deer, and I have never seen them act aggressively towards any other species, including humans, even during the rut. In recent years, several accounts have made headlines in the British tabloids of dogs having been attacked by “vampire deer”. One such article, published in The Daily Mail in April 2009, covered the story of a six-year-old Jack Russell that suffered lacerations to her neck, stomach, and flanks from a “mystery predator” in Ampthill Park, Bedfordshire. The vet treating the dog identified the injuries as having been caused by a Chinese water deer, and stated that this was the sixth dog having been brought in with similar injuries. The article is very poorly researched, however, and an interview with the Ampthill park committee chairman, Hector Chappell, further down describes how the park has a huge population of water deer, partly because “they breed throughout the year”. Clearly, there is confusion here between water deer and Reeves' muntjac (Muntiacus reevesi), the latter of which are known to attack dogs when cornered. At the time of writing, I know of no confirmed attacks by water deer on any other species, and several authors have noted how, even when caught and pinned by a dog or human, these animals make no attempt to fight back; they often just scream.
Writing in 1953, the 12th Duke of Bedfordshire noted that fights were as likely to be seen during the spring as the winter breeding season and:
“... frequently start by one buck running up to another and looking fixedly at him, such a stare being apparently received as an insult of the worst kind.”
Bucks will often approach one another, heads down and neck straight with a rather stiff-legged gait. Often one or other will rotate their head, causing an “ear slapping”, although it's not known whether the intention is to slap the ears (i.e., generating an auditory cue) or if it is a side effect of the buck trying to show off his tusks to an opponent. They may parallel walk while tongue-flicking/mouthing and then “dance” around one another, each trying to land kicks or canine-blows to the head, neck, flank or rump of the other. On his Bedfordshire estate, Paul Childerley has observed that old bucks (i.e., those with chipped, broken or worn-down tusks) are often very aggressive to other males and are preferentially culled. The progression of aggression is described in more detail in the Male-Male Aggression section.
Alongside fights between rival bucks over access to does, there are more subtle non-combative displacements, often between mature bucks and younger animals. Rutting bucks may displace females from their couch to test the ground for impending oestrous, but they may also harry out other bucks. In his small study group, for example, Francois Feer observed that males avoided approaching one another while at rest, keeping their distance even when choosing lying-up sites. His bucks (a mature animal and a younger buck) were found together on only 10% of occasions, and the vegetation in these cases was sufficiently thick to prevent direct eye contact. The dominant male displaced the subordinate from the best, most sheltered resting places such that the subordinate was found resting in uncovered areas more than twice as often as the dominant buck (23% of records vs. 10%). When the dominant male was removed, the subordinate almost invariably selected covered resting sites (85% of records). Sharon Scott described a similar displacement behaviour that she observed in Buckinghamshire in the spring of 2019 during which one deer walked up to another that was lying down, causing it to get up and move off to lie down a few metres away. The “approaching” buck sniffed and then laid down in the spot for a while before getting up and repeating the activity (i.e., displacing the same animal from its new resting spot before taking it over).
Sharon's description is not dissimilar to the “walking chase” described by Feer that involved a dominant animal continuously pursuing a subordinate at a distance of three to 10 metres (10-33 ft.), only stopping when the subordinate laid down or gained sufficient distance. If the subordinate was the first to lie down, the dominant male would come over and make him rise from a distance to resume the pursuit. I've never observed the walking chase/displacement behaviour, but I have seen one deer approach and kick another with a front foot, triggering the resting animal to vacate its couch. Feer noted that as well as kicking, one individual may sometimes climb with two front legs onto the back of the resting animal, precipitating displacement. Typically, aggression is from older/mature animals to younger/immature individuals, although in January 2023 one of my trailcams recorded an immature (first winter) buck give chase to a more mature buck after it exited a field and ran away from it through a narrow spinney.
At Whipsnade, Stefan Stadler described two combative behaviours between females. Head-up involved both animals approaching each other, usually with head held high and ears turned backwards. Stadler observed this to be a precursor to a front-leg-strike and only saw it between females. Second was the high dance, which took place at close range (a metre or two apart) and consisted of females lunging at and striking one another with a downward parallel blow of both front legs. This 'dance' was repeated several times and continued until one withdrew. Unlike the male fights, both females held their head at least a metre (3 ft.) above the ground throughout. Elizabeth Dack photographed a high dance between two does at Upton Broad in Norfolk during February 2020, although her impression was that they were youngsters playing, and these remain the only photos of this behaviour I have encountered.
Michael Clark described what may have been the initiation of (or prelude to) a high dance, in his 1981 book Mammal Watching, which involved one doe putting its ears forward and rushing at another, sometimes kicking out fiercely with forelegs, while Feer observed that females never used teeth during fights, instead exchanging forehead strikes in the flanks, on the neck and head, and more rarely between the hind legs. In their 2011 paper to Acta Theriologica, Gérard Dubost and his colleagues described the same tongue-flicking/mouthing behaviour in does at Branféré Zoological Park in France that's sometimes seen in bucks during a parallel walk:
“When a threat exists [between females], it often consists in tongue flicking in vacuum, sometimes with aborted steps toward the partner, tail up, no kick.”
The researchers noted how conflict between does rarely escalated beyond threats, one surrendering their place if necessary.
Aggression between water deer is usually a within-sex affair (i.e., males towards males and females towards females). Feer, nonetheless, noted that bucks were sometimes aggressive towards females, and in his 1982 paper to Zeitschrift fur Saeugetierkunde, suggested this may imply a sexual hierarchy. I have only seen a buck approach a doe in what appeared to be an aggressive manner once, at Whipsnade, although I have observed signs of what I took to be frustration in a buck (e.g., foot scraping, head shaking and mouthing/tongue-flicking) when a female failed to leave her couch on approach. Equally, Stadler described displaced water deer engaging in brief head shaking as a sign of frustration, and this is something I have also witnessed.
Aggression towards bucks by females seems extremely rare, and Arnold Cooke tells me that he has never observed it. On two occasions I have seen a female turn and scissor-kick at an overzealous buck, but this was brief and there seemed no significant or enhanced aggression behind it. During the 2016/17 winter rut, Sharon Scott to me described pursuit between a buck and doe that involved her “boxing at the male” like hares, although this seems to have been a prelude to copulation rather than aggression per se:
“The buck ran at the doe with his head down, ear-flapping and she ran away squeaking, closely followed by him. She turned a couple of times during the chase and they danced around each other squeaking before she allowed him to mount her.”
Submission
Submission in water deer appears to take three forms: fleeing/withdrawing, head low, and prostration. Fleeing is the most common submissive gesture, both in my experience and based on the accounts I have read in the literature, and can involve anything from a slow walk to a gallop. I've never heard animals vocalise while fleeing, but Stadler recorded it twice at Whipsnade. Lowering of the head appears mostly a female gesture, most often observed when a buck approaches a resting doe. The head is lowered to the ground and the animal remains still until the other individual moves away. In a few instances at Whipsnade, Stadler recorded head shaking if harassment by the approaching animal continued:
“The head-low response clearly indicated the deer’s reluctance to leave the place where it resided.”
Outside of oestrous, most females eventually withdrew in the face of continued attention and, overall, Stadler recorded that approach by one animal led to withdrawal in nearly three-quarters (73%) of cases.
Prostration, which involves the submissive animal taking themselves as low to the ground as possible - including lowering the head to the ground, flattening the ears and remaining absolutely still - seems rare. Stadler observed it only twice, and in both cases it was by a debilitated buck unable to withdraw. The same posture was more frequently observed in animals hiding from human disturbance, which Stadler suggested may be an example of behavioural neoteny, the persistence of the “prone response” of young fawns into adulthood, an adaptive anti-predatory behaviour. Stadler makes no mention of vocalisation from either buck in his thesis, although Bob Lawrence recounted how, having been caught and pinned by a dominant animal, a defeated buck “squealed like a pig”, which is an apparently common response to water deer being caught.