Thesika deer (Cervus nippon), also known as thenorthern spotted deer or theJapanese deer, is aspecies ofdeer native to much ofEast Asia and introduced to other parts of the world. Previously found from northernVietnam in the south to theRussian Far East in the north,[1] it wasoverhunted 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.[2]
The name "sika deer" comes fromshika (鹿), theJapanese word for "deer", and inJapan the species is known as thenihonjika (ニホンジカ (日本鹿), "Japan deer"). InChinese, it is known as梅花鹿;méihuālù; 'plum blossom deer', referring to the whitefur spots on the deer's back resemblingplum blossoms.
The sika deer is a member of thegenusCervus, a group of deer also known as the "true" deer, within the larger deerfamily,Cervidae. Formerly, sika were grouped together in this genus with nine other diverse species; these animals have since been found to be genetically different, and reclassified elsewhere under different genera. Currently, deer species within the genusCervus are the sika, thered deer (C. elaphus) of Scotland, Eurasia and Northern Africa (introduced in Argentina, Australia, New Zealand), and thewapiti, or elk (C. canadensis), of North America, Siberia and North-Central Asia.[3]
DNA evidence indicates that the species formerly placed underCervus are not as closely related as once thought, resulting in the creation of several new genera. The ancestor of allCervus species probably originated inCentral Asia and possibly resembled the sika deer.[4] Members of this genus can crossbreed and producehybrids in areas where they coexist. This includes sika and wapiti; in theScottish Highlands, the interbreeding of nativeScottish red deer with introduced sika has been deemed a serious threat to the gene pool of the Scottish deer.[5] However, by comparison, an invasive sika deer in the United States cannot reproduce with a North Americanwhite-tailed,mule orblack-tailed deer, all of which are placed in a separate genus,Odocoileus.
Seriousgenetic pollution has occurred in manypopulations, especially in China, so the status of manysubspecies remains unclear.[1] The status ofC. n. hortulorum is particularly uncertain and might in fact be of mixed origin, hence it is not listed here.
The sika deer is one of the few deer species that does not lose its spots upon reaching maturity. Spot patterns vary with region. The mainland subspecies have larger and more obvious spots, in contrast to theTaiwanese and Japanese subspecies, whose spots are nearly invisible. Many introduced populations are from Japan, so they also lack significant spots.
The color of thepelage 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.[9] They are medium-sizedherbivores, though they show notable size variation across their several subspecies and considerablesexual dimorphism, with males invariably much larger than females. They can vary from 50 to 110 cm (20 to 45 in) tall at the shoulder and from 95 to 180 cm (35 to 70 in) in head-and-body length. The tail measures about 7.5–13 cm (3–5 in) long.
The largest subspecies is theManchurian sika deer (C. n. mantchuricus), in which males commonly weigh about 68–109 kg (150–240 lb) and females weigh 45–50 kg (100–110 lb), with large stags scaling up to 160 kg (350 lb), although there had been records ofYezo sika deer bulls weighing up to 170 or 200 kg (370 or 440 lb).[10][11] On the other end of the size spectrum, in the Japanese sika deer (C. n. nippon), males weigh 40–70 kg (90–150 lb) and females weigh 30–40 kg (70–90 lb).[12][13] All sikas are compact and dainty-legged, with short, trim, wedge-shaped heads and a boisterous disposition. When alarmed, they often display a distinctive flaredrump, much like the Americanelk.
Sika stags have stout, uprightantlers with an extra buttress up from the browtine 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 28 to 45 cm (11 to17+1⁄2 in) to more than 80 cm (30 in), depending on the subspecies. Stags also have distinctive manes during their mating period (rut).
These deer have well-developed metatarsal and preorbitalglands. The volatile components of these glands were examined from a free-ranging female. The metatarsal gland contained 35 compounds: long-chaincarboxylic acids, straight-chainaldehydes, long-chain alcohols, aketone, and cholesterol.[14] The components of thepreorbital gland were C14 through C18 straight and branched-chain fatty acids.[15]
Manchurian sika deerMale calling, recorded at Wareham, Dorset, England, October 1964
Sika deer can be active throughout the day, though in areas with heavy human disturbance, they tend to benocturnal.Seasonal migration is known to occur in mountainous areas, such as Japan, with winter ranges being up to 700 m (2,300 ft) lower in elevation than summer ranges.
Lifestyles vary between individuals, with some occurring alone while others are found in single-sex groups. Largeherds gather in autumn and winter. Males spend most years alone occasionally forming herds together. Females with fawns only form herds during birthing season.[16] 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 keepharems of females during their rut, which peaks from early September through November,[17] but may last well into the winter.Territory size varies withhabitat type and size of the buck; strong, prime bucks may hold up to two hectares (five acres). 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,[16] into which the males urinate and from which emanates a strong,musky odor. Fights between rival males for territorial disputes, which occur by using hooves and antlers,[16] are sometimes fierce and long and may even be fatal.
Thegestation period lasts for seven months. Hinds (does) give birth to a single fawn, weighing 4.5 to 7 kg (10 to 15 lb), which is nursed for up to ten months.[16] 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,[17][16] 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.[16]
The sika deer may interbreed with thered deer, the closest relative; hybrid descendants may have adaptive advantages over purebred relatives.[16]
InNara Prefecture, Japan, the deer are also known as "bowing deer", as they have learned to bow their heads before being fed specialshikasenbei (鹿せんべい, called "deer cookies"). However, deer also bow their head to signal that they are about toheadbutt. 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 thecity of Nara and its many parks likeNara Park and temples likeTōdai-ji, as they are considered to be the messengers of theShinto gods.[18][19]
Sika deer are found in thetemperate andsubtropical forests ofeastern Asia, preferring areas with dense understory and occasional clearings and where snowfall does not exceed 10–20 cm (4–8 in),[20] though in theirnative range they have been known to frequent areas with a maximum snow depth of up to 50 cm (19.6 in).[21] They tend to forage in patchy clearings of forests.[citation needed] Introduced populations are found in areas with similar habitats to their native ranges, including Western and Central Europe, Eastern United States, andNew Zealand.[22]
Sika deer inhabit temperate and subtropical woodlands, often inareas suitable for farming and other human exploitation. Their range encompasses some of the most densely populated areas in the world, where forests were cleared hundreds of years ago. Their population status varies significantly in different countries. Although the species as a whole is thriving, it is endangered and extinct in many areas.
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,[23] mainly due to recent conservation efforts and the extinction of its main predator, theJapanese wolf (Canis lupus hodophilax), over a century ago. Without its main predator, the population of sika exploded and it is now overpopulated in many areas, posing a threat to both forests and farmlands. Efforts are now being made to control its population instead of conserving it. None of its subspecies isendangered except theKerama deer (C. n. keramae) on the tinyKerama Islands.[2]In 2015,Japanese Ministry of the Environment estimated the population at 3,080,000 in Japan, includingHokkaido.[24]
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.[1] Of the five subspecies in China, theNorth China sika deer (C. n. mandarinus) is believed to be extinct in the wild since the 1930s; theShanxi 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 ofManchurian sika deer in China is unclear, though it is also believed to be extinct, and the sightings there are actually feral populations.
TheSouth China sika deer (C. n. kopschi) andSichuan 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.
TheFormosan sika deer (C. n. taioanus) has been extinct in the wild for almost two decades before individuals from zoos were introduced toKenting National Park; the population now numbers 200. Reintroduction programs are also under way inVietnam, where theVietnamese sika deer (C. n. pseudaxis) isextinct or nearly so.
Russia has a relatively large and stable population of 8,500–9,000 individuals of the Manchurian subspecies,[1] but this is limited to a small area inPrimorsky Krai. Small populations might exist inNorth Korea, but the political situation makes investigation impossible. The original stock of sika deer inSouth 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.[25]
In the UK and Ireland, several distinct feral populations now exist, in addition to about 1000 individuals in deer parks.[30] Some of these are in isolated areas, for example on the island ofLundy,[31] but others are contiguous with populations of the nativered deer.[30] Since the two species sometimeshybridize, a serious conservation concern exists.[32] In the United Kingdom, Sika deer are most common inScotland, with scattered smaller populations inEngland - particularlyCumbria,Lancashire,Dorset and in theNew Forest - andNorthern Ireland. The introduced populations of the United Kingdom are exclusively of the nominate subspeciesC. n. nippon.[33]
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 thebrown rat andmuskrat.[34]
Across its original range and in many areas to which it has been introduced, the sika is regarded as a particularly prized and elusivesportsman's quarry. In Britain, Ireland, and mainland Europe, sika display very different survival strategies and escape tactics from theindigenous deer. They have a marked tendency to use concealment in circumstances when red deer, for example, would flee, and have been seen to squat and lie belly-flat when danger threatens.
In theBritish 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.[37]
^Senn, Helen."Hybridisation between sika and red deer"(PDF). University of Edinburgh. Retrieved5 December 2022.Hybridisation is predominantly occurring between sika stags and red deer hinds.
^Wood, William F. (2004). "Straight- and branched-chain fatty acids in the preorbital gland of sika deer, Cervus nippon".Journal of Chemical Ecology.30 (2):479–482.doi:10.1023/B:JOEC.0000017996.65270.d7.PMID15112737.
^abcdefghLandesman, N."Cervus nippon".University of Michigan Museum of Zoology. Animal Diversity Web.
^Takatsuk, Seiki (1992). "Foot morphology and distribution of Sika deer in relation to snow depth in Japan".Ecological Research.7 (1):19–23.doi:10.1007/BF02348593.
^Wu, Feifei; Li, Huaqiang; Jin, Liji; Li, Xiaoyu; Ma, Yongsheng; You, Jiansong; Li, Shuying; Xu, Yongping (2013). "Deer antler base as a traditional Chinese medicine: A review of its traditional uses, chemistry and pharmacology".Journal of Ethnopharmacology.145 (2):403–415.doi:10.1016/j.jep.2012.12.008.PMID23246455.
O'Brien, David J.; Rooney, Seán M.; Hayden, Thomas J. (2009). "A differential vulnerability to hunting between the sexes in Sika-type calves".The Irish Naturalists' Journal.30:7–9.JSTOR20764516.
