Water deer
From Wikipedia, the free encyclopedia
| Water Deer | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 |
||||||||||||||||
| Conservation status | ||||||||||||||||
| Scientific classification | ||||||||||||||||
|
||||||||||||||||
| Binomial name | ||||||||||||||||
| Hydropotes inermis (Swinhoe, 1870) |
The Water Deer (Hydropotes inermis) is superficially more similar to a musk deer than a true deer (Cervidae - order Artiodactyla) but it is classified as a cervid despite having tusks (downward-pointing canine teeth) instead of antlers and other anatomical anomalies. These unique characteristics have caused it to be classified in its own genus (Hydropotes) and its own subfamily (Hydropotinae). Native to China and Korea, there are two subspecies: the Chinese Water Deer (Hydropotes inermis inermis) and the Korean Water Deer (Hydropotes inermis argyropus).
Contents |
[edit] Habitat & Distribution
Water deer are indigenous to the lower reaches of the Yangtze River, coastal Jiangsu province (Yancheng Coastal Wetlands), and islands of Zhejiang of east-central China, and in Korea--where the DMZ has provided a protected habitat for a large number. They frequent the tall reeds, rushes along rivers, and in tall grass on mountains and cultivated fields as well as swampy regions and open grasslands. They have also been known to inhabit swamps, and when the cultivated fields that they occupied are cut, they may be found lying in the furrows and hollows of the open field.
A proficient swimmer, water deer can also swim several miles to make use of river islands.
[edit] Britain
Chinese Water Deer were first introduced into Britain in the 1870s and were kept in the London Zoo. In 1896, they were transferred to Woburn Abbey, Bedfordshire, with further additions being imported and added to the stock. In 1929 and 1930, 32 deer were transferred from Woburn to Whipsnade, also in Bedfordshire, and released into the park. It is thought that the current Chinese Water Deer population at Whipsnade is over 600 whilst at Woburn it is probably in the region of 250 plus.
The present feral population derives from a number of deliberate releases, however, the majority have descended from escapees. The majority of the wild Chinese Water Deer population still resides in close proximity to Woburn Abbey. It appears that the deer’s strong preference for a particular habitat – tall reed and grass areas in rich alluvial deltas - has restricted its potential to colonize further afield. The main area of distribution is from Woburn, east into Cambridgeshire, Norfolk and Suffolk, and south towards Whipsnade. There have been small colonies reported in other areas.
[edit] France
There are currently small, highly localized feral populations.
[edit] Physical Attributes
| Body Length | Shoulder Height | Tail Length | Weight |
|---|---|---|---|
| 75-100 cm | 45-55 cm | 6-7.5 cm | 9-14 kg |
| 2.5-3.3 ft | 18-22 in | 2.4-3 in | 20-31 lbs |
The water deer has narrow pectoral and pelvic girdles, long legs, and a long, graceful neck. The powerful hind legs are longer than the front legs, so that the haunches are carried higher than the shoulders. They run with rabbit-like jumps. In the groin of each leg is an inguinal gland used for scent marking; this deer is the only member of the Cervidae to possess such glands. The short tail is no more than 5-10 cm / 1.9–3.8 in. in length and is almost invisible, except when it is held raised by the male during the rut. The ears are short and very rounded, and both sexes lack antlers.
The coat is an overall golden brown color, and may be interspersed with black hairs, while the undersides are white. The strongly tapered face is reddish brown or gray in color, and the chin and upper throat are cream colored. The hair is longest on the flanks and rump. In the fall, the summer coat is gradually replaced by a thicker, coarse-haired winter coat that varies from light brown to grayish brown. Neither the head nor the tail poles are well differentiated as in gregarious deer; consequently, this deer's coat is little differentiated.
Young are born dark brown with white stripes and spots along their upper torso.
[edit] Tusks
The water deer have developed long canine teeth which protrude from the upper jaw like the canines of musk deer. The canines are fairly large in the bucks. They're 5.5 cm / 2.1 in. in length on average but can be as long as 8 cm / 3.2 in. Does in comparison, have tiny canines that are on an average of 0.5 cm / 0.2 in. in length.
The teeth usually erupt in the autumn of the deer’s first year at approximately 6-7 months of age. By early spring the recently erupted tusks reach approximately 50% of their final length. As the tusks develop, the root remains open until the deer is about eighteen months to two years old. When fully grown, only about 60% of the tusk is visible below the gum.
At the end of the male's first winter, his canines will be about half their full size; final length is reached after about 18 months. These canines are held loosely in their sockets, with their movement controlled by facial muscles. The buck can draw them backwards out of the way when eating. In aggressive encounters, he thrusts his canines out and draws in his lower lip to pull his teeth closer together. He then presents an impressive two-pronged weapon to rival males.
[edit] Behavior
Apart from during the rutting season, water deer are solitary animals, and males are highly territorial. Each buck marks out his territory with urine and feces. Sometimes a small pit is dug and it is possible that in digging, the male releases scent from the interdigital glands on its feet. The male also scent-marks by holding a thin tree in his mouth behind the upper canines and rubbing his pre-orbital glands against it. Males may also bite off vegetation to delineate territorial boundaries.
Confrontations between males begin with the animals walking slowly and stiffly towards each other, before turning to walk in parallel 10-20 m / 32–64 ft. apart, to assess one another. At this point, one male may succeed in chasing off his rival, making clicking noises during the pursuit. However, if the conflict is not resolved at the early stage, the bucks will fight. Each would try to wound the other on the head, shoulders, or back, by stabbing or tearing with his upper canines. The fight is ended by the loser, who either lays his head and neck flat on the ground, or turns tail and is chased out of the territory. Numerous long scars and torn ears seen on males indicate that fighting is frequent. The fights are seldom fatal but may leave the loser considerably debilitated. Tufts of hair are most commonly found on the ground in November and December, showing that encounters are heavily concentrated around the rut.
Females do not seem to be territorial outside the breeding season and can be seen in small groups, although individual deer do not appear to be associated; they will disperse separately at any sign of danger. Females show aggression towards each other immediately before and after the birth of their young and will chase other females from their birth territories.
[edit] Communication
Water deer are capable of emitting a number of sounds. The main call is a bark and this has more of a growl tone when compared with the sharper yap of a Muntjac. The bark is used as an alarm and water deer will bark repeatedly at people and at each other for reasons unknown. If challenged during the rut, a buck will emit a clicking sound. It is uncertain how this unique sound is generated, although it is possibly by using its molar teeth. During the rut a buck following a doe will make a weak whistle or squeak. The does emit a soft pheep to call to their fawns, whilst an injured deer will emit a screaming wail.
[edit] Reproduction
| Gestation Period | Young per Birth | Sexual Maturity | Life Span |
|---|---|---|---|
| 180-210 days | 1-7 | Does: 7-8 months | 10-12 years |
| Commonly 2-5 | Bucks: 5-6 months |
During the annual rut in November and December, the male will seek out and follow females, giving soft squeaking contact calls and checking for signs of estrus by lowering his neck and rotating his head with ears flapping. Scent plays an important part in courtship, with both animals sniffing each other. Mating among water deer is polygynous, with most females being mated inside the buck's own territory. After repeated mountings, copulation is brief.
Water deer have been known to produce up to seven young, but two to three is normal for this species, the most prolific of all deer. The doe often gives birth to her spotted young in the open, but they are quickly taken to concealing vegetation, where they will remain most of the time for up to a month. During these first few weeks, fawns come out to play. Once driven from the natal territory in late summer, young deer sometimes continue to associate with each other, later separating to begin their solitary existence.
In a survey of zoos, however, it was found that there were usually only two offspring per birth or occasionally three on the average.
[edit] References
- Deer Specialist Group (1996). Hydropotes inermis. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006.
[edit] External links
