The sika deer ( Cervus nippon), also known as the northern spotted deer or the Japanese deer, is a species of deer native to much of East Asia and introduced to other parts of the world. Previously found from northern Vietnam in the south to the Russian Far East in the north, it was overhunting to the brink of extinction in the 19th century. Protection laws were enacted in the mid-20th century, leading to a rapid recovery of their population from the 1950s to the 1980s.
DNA evidence indicates that the species formerly placed under Cervus are not as closely related as once thought, resulting in the creation of several new genera. The ancestor of all Cervus species probably originated in Central Asia and possibly resembled the sika deer. Members of this genus can crossbreed and produce hybrids in areas where they coexist. This includes sika and wapiti; in the Scottish Highlands, the interbreeding of native Scottish red deer with introduced sika has been deemed a serious threat to the gene pool of the Scottish deer. However, by comparison, an invasive sika deer in the United States cannot reproduce with a North American white-tailed, mule deer or black-tailed deer, all of which are placed in a separate genus, Odocoileus.
The color of the pelage ranges from mahogany to black, and white individuals are also known. During winter, the coat becomes darker and shaggier and the spots less prominent, and a mane forms on the back of the males' necks. They are medium-sized herbivores, though they show notable size variation across their several subspecies and considerable sexual dimorphism, with males invariably much larger than females. They can vary from tall at the shoulder and from in head-and-body length. The tail measures about long.
The largest subspecies is the Manchurian sika deer ( C. n. mantchuricus), in which males commonly weigh about and females weigh , with large stags scaling up to , although there had been records of Yezo sika deer bulls weighing up to .『エゾシカは森の幸 人・森・シカの共生』p.63 On the other end of the size spectrum, in the Japanese sika deer ( C. n. nippon), males weigh and females weigh . All sikas are compact and dainty-legged, with short, trim, wedge-shaped heads and a boisterous disposition. When alarmed, they often display a distinctive flared rump, much like the American elk.
Sika stags have stout, upright with an extra buttress up from the brow tine and a very thick wall. A forward-facing intermediate tine breaks the line to the top, which is usually forked. Occasionally, sika antlers develop some palmation (flat areas). Females carry a pair of distinctive black bumps on the forehead. Antlers can range from to more than , depending on the subspecies. Stags also have distinctive manes during their mating period (rut).
These deer have well-developed metatarsal and preorbital Gland. The volatile components of these glands were examined from a free-ranging female. The metatarsal gland contained 35 compounds: long-chain Carboxylic acid, straight-chain Aldehyde, long-chain alcohols, a ketone, and cholesterol. The components of the preorbital gland were C14 through C18 straight and branched-chain fatty acids.
Lifestyles vary between individuals, with some occurring alone while others are found in single-sex groups. Large Herd gather in autumn and winter. Males spend most years alone occasionally forming herds together. Females with fawns only form herds during birthing season. The sika deer is a highly vocal species, with over 10 individual sounds, ranging from soft whistles to loud screams.
Sika males are territorial and keep harems of females during their rut, which peaks from early September through November, but may last well into the winter. Territory size varies with habitat type and size of the buck; strong, prime bucks may hold up to . Territories are marked by a series of shallow pits or "scrapes", which is digging holes (up to 1.6 m in wide and 0.3 m in deep) with forefeet or antlers, into which the males urinate and from which emanates a strong, odor. Fights between rival males for territorial disputes, which occur by using hooves and antlers, are sometimes fierce and long and may even be fatal.
The gestation period lasts for seven months. Hinds (does) give birth to a single fawn, weighing , which is nursed for up to ten months. The mother hides her fawn in thick undergrowth immediately after giving birth, and the fawn stays very quiet and still while it waits until the mother returns to nurse it. The fawn becomes independent 10 to 12 months after birth, and attains sexual maturity at 16 to 18 months in both sexes. The average lifespan is 15 to 18 years in captivity, although one case is recorded as living 25 years and 5 months.
The sika deer may interbreed with the red deer, the closest relative; hybrid descendants may have adaptive advantages over purebred relatives.
In Nara Prefecture, Japan, the deer are also known as "bowing deer", as they have learned to bow their heads before being fed special . However, deer also bow their head to signal that they are about to headbutt. Therefore, when a human "bows" to a deer, the deer may take it as a challenge, and will assume the same stance before charging and attempting to headbutt the person. Deer headbutt both for play and to assert dominance, as do goats. Sika deer are found throughout the city of Nara and its many parks like Nara Park and temples like Tōdai-ji, as they are considered to be the messengers of the Shinto gods.
Japan has by far the largest native sika population in the world. The population was estimated to be between 170,000 and 330,000 individuals in 1993,
China used to have the largest population of sika, but thousands of years of hunting and habitat loss have reduced the population to less than 1,000. Of the five subspecies in China, the North China sika deer ( C. n. mandarinus) is believed to be extinct in the wild since the 1930s; the Shanxi sika deer ( C. n. grassianus) has not been seen in the wild since the 1980s and is also believed to be extinct in the wild. The status of Manchurian sika deer in China is unclear, though it is also believed to be extinct, and the sightings there are actually feral populations.
The South China sika deer ( C. n. kopschi) and Sichuan sika deer ( C. n. sichuanicus) are the only subspecies known to remain in the wild in China. The former exists in fragmented populations of around 300 in southeast China, while the latter is found in a single population of over 400. The feral population is likely to be much higher than the wild, though most of them are descended from domesticated sikas of mixed subspecies. All of the subspecies are present in captivity, but a lack of suitable habitats and government efforts prevent their reintroduction.
The Formosan sika deer ( C. n. taioanus) has been extinct in the wild for almost two decades before individuals from zoos were introduced to Kenting National Park; the population now numbers 200. Reintroduction programs are also under way in Vietnam, where the Vietnamese sika deer ( C. n. pseudaxis) is extinct or nearly so.
Russia has a relatively large and stable population of 8,500–9,000 individuals of the Manchurian subspecies, but this is limited to a small area in Primorsky Krai. Small populations might exist in North Korea, but the political situation makes investigation impossible. The original stock of sika deer in South Korea is extinct, with only captive stock raised for medicine from other parts of the deer's habitat. But in June 2020, an unmanned camera located a doe and fawn which might hold proof for Korea's last native sika deer, although the claim is contested.
In the UK and Ireland, several distinct feral populations now exist, in addition to about 1000 individuals in deer parks.
In research which rated the negative impact of introduced mammals in Europe, the sika deer was found to be among the most damaging to the environment and economy, along with the brown rat and muskrat.
In the 1900s, King Edward VII presented a pair of sika deer to John, the second Baron Montagu of Beaulieu. This pair escaped into Sowley Pond Wood and were the basis of the sika to be found in the New Forest today. They were so prolific, culling had to be introduced in the 1930s to control their numbers.
In the British Isles, sika are widely regarded as a serious threat to new and established woodlands, and public and private forestry bodies adopt policies of rigorous year-round culling.
The main predators of sika deer include Siberian tiger, Japanese wolf, Amur Leopard, and brown bears. Lynx and target fawns.
Other deer raised for the antler trade were Thorold's deer ( Cervus albirostris), central Asian red deer ( Cervus hanglu), and elk ( Cervus canadensis).
Habitat
Population
Introduced populations
Hunting
Deer farming
Velvet antler
Cultural significance
See also
Further reading
External links
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