Saturday, February 26, 2011

The Incredible Korea and its Flora and Fauna : Water Deer

Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include White-tailed deer, Elk, Moose, Red Deer, Reindeer, Roe and Chital. Male deer of all species, except the Chinese or Korean Water deer, and female Reindeer grow and shed new antlers each year.
The word "deer" was originally broad in meaning, but became more specific over time. In Middle English der (Old English dēor) meant a wild animal of any kind .

The Water Deer (Hydropotes inermis) is superficially more similar to a musk deer than a true deer (Cervidae - order Artiodactyla). Whereas, 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).



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 demilitarized zone 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.

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.



Tusks
A stuffed specimen of H. inermis illustrating its tusks at the National Museum of Natural History.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, ranging in length from 5.5 cm / 2.1 in. on average to 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.

It is due to these tusks that locals colloquially refer to this animal as a "vampire deer."

CommunicationWater 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.

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.



At one time water deer used to occurred throughout the wetlands of eastern China from Guangdong to Liaoning, and in all of Korea, but much habitat has been lost in recent years due to hunting . Now found in most of the central and eastern river valleys in China between latitudes 28-35°N and east of about longitude 111°E, and in the lower reaches of all large Korean rivers except those in the northeast.

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