Water Deer Activity - Activity Patterns
While it is difficult to generalise about the activity patterns of any species, deer tend broadly to be crepuscular animals, most active around dawn and dusk. Water deer appear to conform to this pattern, though the details vary considerably according to location, season, weather, and -- in all likelihood -- the individual animal. (Note: The activity of water deer in the context of the rut is discussed in the Rutting and Courtship section.)
Chronology
Most studies, both in the UK and across the water deer's native range, suggest they feed primarily around sunrise and sunset, though they can be active at any time of day or night. From May 1988 to April 1989, Lixing Sun and Bing Xiao studied the behaviour of 22 individually identifiable deer at Jiniushan Hill in China's Jiangxi province, observing that daytime activity divided into two distinct active periods: sunrise to 10:00, and 15:30 to sunset. Between these windows, Sun and Xiao report in their 1995 paper to Zeitschrift für Säugetierkunde, the deer were mostly resting, ruminating, or sleeping – though the authors did not break their results down by season, and most observations fell between October 1988 and January 1989. In the UK, Michael Clarke, writing in his 1981 book Mammal Watching, described water deer feeding primarily at dawn and dusk, with shorter bouts around midday and midnight. Endi Zhang, during his Ph.D. studies at Whipsnade Zoo, found feeding peaks between 06:00 and 10:00 and again between 17:00 and 21:00, with a lull between 11:00 and 13:00, and these observations broadly correspond with my own, both at the zoo and in the field: outside the rut, most deer rest during the day, although I have noticed a tendency for some animals to graze briefly around midday. During the rut, both sexes can be active throughout the day, though much of this is driven by males repeatedly disturbing and pursuing resting females.
In Huxia Park in Shanghai's Pudong New Area, Feiyan Ma monitored water deer during the spring and summer of 2008 and identified two main activity peaks, one in the morning (06:00-07:00) and one in the evening (18:00-19:00), with a much smaller third peak around midday (11:00-13:00). More recently, Qian Han and colleagues at the Nanjing Forestry University examined activity patterns via 35 camera traps in Laoshan Forest Park between October 2020 and March 2021. Their 2022 paper to the Chinese Journal of Ecology described a typical bimodal pattern, with intensive daily activity between 04:00 and 06:00 and again between 18:00 and 20:00. Activity peaked during December, and overall intensity was highest when temperatures fell between 4C and 6C (39-43F). A subsequent 2024 study in the same journal, by Huiyu Liu and colleagues, tracked eight satellite-collared, captive-bred water deer released as part of a reintroduction programme in the hilly lower reaches of the Yangtze River between October 2022 and November 2023. The data showed peak activity between 03:00 and 06:00 and again between 15:00 and 18:00, with the lowest activity recorded between 09:00 and noon.
On the Stat Nature Reserve at Dafeng in eastern China during February and March 2001, Xiaolong Zhang and Endi Zhang found a rather different arrangement: water deer spent most of the daytime lying up among long grass in the wetland, well away from human disturbance, before moving into nearby wheat and oilseed rape fields at night to feed. This nocturnal feeding strategy offers a useful reminder of how much local conditions can shape activity patterns. Baek Jun Kim and Sang-Don Lee, working in northern South Korea in 2009, found that water deer moved around to feed both by day and night, though more actively after dark. During the night-time hours they were largely ruminating, while the daytime was split between ruminating and resting. The animals tended to move most actively just after dawn (05:00-07:00) and in the run-up to sunset (17:00-19:00), typically heading to feeding or resting sites during those windows.
The picture that emerges from Korea is corroborated by longer-term camera trap work along the Baekdudaegan ridge conservation area, where Hwa-Jin Lee and colleagues monitored mammal activity between June 2015 and May 2016. Water deer proved to be the most commonly photographed species, accounting for 20% of all images and appearing both day and night. The majority of photographs (65%) were taken overnight (18:00-07:00), with animals frequently captured around 19:00. The data published in the Journal of Asia-Pacific Biodiversity in 2019 are difficult to interpret owing to limited methodological detail and no separation by season, but one notable finding concerns the deer's apparent indifference to human walkers: on average, animals were photographed just 17 minutes after a hiker had passed by, suggesting relatively little displacement by recreational disturbance in this area. That said, the standard deviation was 17 minutes and 49 seconds -- slightly higher than the mean of 17 minutes and 1 second -- indicating considerable variation between individuals.
While the consistency of a broadly crepuscular pattern across these studies is striking, data from two national parks in South Korea (one in the north, one in the south) collected across the summers of 2019 to 2021 show that populations can depart significantly from this template in response to local conditions. Deer in Seoraksan exhibited a clear dusk activity peak, while those at Jirisan tended to be active throughout the day and mostly inactive overnight. In their 2023 paper to the Pakistan Journal of Zoology, Tae-Kyung Eom and colleagues suggest these differences may reflect variation in predation pressure and interspecific competition with roe deer (Capreolus capreolus) and Amur gorals (Naemorhedus caudatus).
Disturbance and evasion
Disturbance appears to play a significant role in shaping activity patterns, and the relationship between water deer and human presence is a nuanced one. In Mammals of Korea, Yeong-Seok Jo, John Baccus, and John Korprowski note that this species appears to become progressively nocturnal with increasing human disturbance; a pattern supported by the observations of Haiming Tang and colleagues, who found that when water deer at the Nanhui reserve in Shanghai were subjected to disturbance by feral domestic dogs, they shifted their activity accordingly to avoid encounters. In personal correspondence, Arnold Cooke considered it likely that, given their generally "flighty" nature, water deer would probably become more nocturnal during protracted culling, though he acknowledged that data on this are lacking.
Water deer can certainly be skittish animals. Clarke noted that they panic easily and require plenty of cover, becoming more relaxed as vegetation thickens through late spring and summer. This matches my own experience: apart from bucks during the rut, water deer tend to flee at even relatively mild disturbance, and it is not uncommon for an animal to explode from a ditch or field margin that would have gone entirely unnoticed had it simply stayed put. Yet individual variation is considerable. Stephen Plummer, a Bedfordshire-based naturalist, recently observed a doe at one of the county's country parks that continued to graze unperturbed within approximately 100 metres (328 ft.) of him and his wife in February 2022. And Paul Childerley, who manages ground in Bedfordshire, has told me that water deer on his land are, if anything, easier to cull towards the end of the shooting season – spring sunshine and warmth drawing them out into open fields rather than driving them to cover.
Seasonal rhythms
While completing his Ph.D. at Whipsnade, Stefan Stadler observed that the year could be roughly divided into four biologically meaningful periods: winter (February to April), when the rut was over and forage quality was poor; fawning (May to July), when the mother-offspring bond was at its most intense and vegetation cover and quality were highest; summer (August to October), when the bond between doe and fawn dissolved and vegetation height and quality declined; and rut (November to January), with activity peaking in the first half of December and vegetation at its lowest. Stadler observed the deer across six-hour periods and, based on 23 animals, found that daytime activity was greatest during the fawning period (around 210 minutes of the observation window), followed by the rut (200 minutes), winter (185 minutes), and summer (160 minutes).
Longer-term fieldwork at Woodwalton Fen in Cambridgeshire, conducted by Arnold Cooke and Lynne Farrell over several decades, offered a detailed picture of how activity shifts with habitat and season. Their initial three years of survey work established that water deer activity was closely tied to sunset, with almost four times as many sightings recorded in the half-hour before sunset than in any other 30-minute period across the preceding two hours. This relationship held throughout the year. While there was a tendency to see more deer during daylight hours in winter, overall only around 10% of activity occurred between sunrise and sunset.
Remote cameras on the reserve allowed Cooke to examine how activity varied by habitat and time of year. In areas of sallow-carr between November and February, 42% of activity fell between 16:00 and 18:00, with around 21% occurring in the early morning between 06:00 and 08:00; a further 14% was recorded between 23:00 and 01:00. By April, 72% of activity was concentrated in a four-hour window around dusk (18:00–22:00), with 21% just before dawn. In sallow coppice between May and July -- the main period of vegetation regrowth -- 31% of activity occurred between 20:00 and 23:00, with only 17% during the daytime hours of 08:00 to 19:00. Trail cameras on deer paths between the reserve and surrounding farmland revealed that the Woodwalton animals frequently left at night to feed in nearby fields, though the tendency to remain out all night varied between years. The cameras also captured a drop in movement along these paths in May, as the grass outside the reserve seeded and became less palatable and females approached calving – a pattern consistent with Cooke's field counts, which showed a decline in animals visible on farm fields around dusk from April into May.
Camera trapping within the WWF reserve during the summer of 2011 showed water deer active throughout the day, although as with the Whipsnade animals, activity dipped to a minimum around midday. My own trail cameras, deployed across three winters on a farm in Buckinghamshire, recorded water deer at all hours during December and January. My personal observations in the field there, in Bedfordshire, and in Norfolk confirm a tendency for greater activity at dusk and through the night, with animals more likely to be found resting or ruminating during the late morning and early afternoon. Even during the rut, when daytime activity increases noticeably, there is a clear uptick as dusk falls.
Captive studies
Studies on captive animals, while not always directly applicable to wild populations, have added important context. During his thesis on the behaviour of water deer, Reeves' muntjac (Muntiacus reevesi), and Indian muntjac (Muntiacus muntjak), Wolf-Peter Scherpe observed animals kept at Berlin Zoo from December 1967 to May 1969, concluding that water deer were considerably more diurnal than either muntjac. This view was echoed just over a decade later by François Feer, a naturalist at the Centre d'Écologie générale de Brunoy, who monitored five adult water deer (two males, three females) at Der Grüne Zoo Wuppertal in Germany during May and June 1980. In his 1982 paper to Zeitschrift für Säugetierkunde, Feer concluded that Hydropotes "must be a strongly diurnal species in its natural environment", pointing to an evening increase in activity without any extended rest period during the day. He also found that weather influenced the pace of activity, with predictably less activity around mid-afternoon in very hot conditions and more evenly distributed activity during cooler temperatures. It should, of course, be noted that the confinement of captive animals may generate activity patterns that differ from those of free-ranging or wild populations.
His and hers
Sex-related differences in activity patterns are apparent across several studies, though the picture is complex. Feer observed that the two males in his group were more active during the daytime (06:00-22:00) than the females: 43% of bucks' active time fell within these hours compared with just 27% for does. In Huxia Park, Feiyan Ma found activity levels broadly similar between the sexes, with most time spent resting or feeding, though females fed for longer than males during the summer, and longer in summer than in spring – presumably reflecting the increased energetic demands of lactation.
At Branféré Animal Park in southern Brittany, Christiane and Robert Mauget observed water deer between November 2002 and July 2005 and found that does spent roughly twice as much time resting as feeding during the day for most of the year, but that feeding time increased significantly during lactation. Compared with the non-pregnant state, daytime grazing was around twice as high during gestation and three times higher during lactation, with corresponding reductions in resting time: 16% less during gestation and 34% less during lactation. At Whipsnade, females spent just over half (55%) of their time feeding during summer, compared with just under half (45%) in males, presumably reflecting milk production peaking in the run-up to weaning. Both sexes fed least during the December rut (around 40% of the time), with males increasing to 57% in February.
Scan sampling of ten lactating females at the Fuyang Chinese Water Deer Farm in Hangzhou, conducted by Guoliang Tan and colleagues between July and August 2014, revealed significantly more daytime than night-time activity. Does spent just over 70% of the night resting and just under 50% of the day in the same state; moving, feeding, ruminating, and social behaviour were all more likely to occur during daylight hours. Two feeding peaks were recorded -- 06:00-07:00 and 16:00-17:00 -- with rumination peaking an hour or two later.
These captive studies inevitably leave gaps. We have relatively little information about how activity budgets vary in wild populations, particularly between the sexes in different seasons. My own observations in Bedfordshire and Buckinghamshire, together with those of Lixing Sun at the Poyang Lake National Nature Reserve between May 1988 and January 1989, suggest that females within the territories of rutting bucks may spend less time feeding and resting than solitary does outside the rut, largely because they are repeatedly pursued by amorous males. Territory-holding males, meanwhile, spend much of their time patrolling, scent-marking, chasing rival bucks, and hounding females – all of which significantly reduces the time available for food and rest.
Bibliography
Cooke, A.S. 2019.
Muntjac and Water Deer: Natural History, Environmental Impact and Management.
Pelagic Publishing. ISBN: 978-1784271909