Sika Deer

The sika deer is a medium-sized deer native to much of East Asia, living in temperate and subtropical forests with dense understory and occasional clearings. It is one of the few deer that keeps its spots into adulthood, though the spots are nearly invisible in the Japanese and Taiwanese subspecies. Active through the day where undisturbed, sikas live alone or in single-sex groups, and large herds gather in autumn and winter. During the rut, males hold territories marked with scrapes and guard harems. The species is highly vocal, with more than 10 distinct sounds from soft whistles to loud screams.

About the sika deer

The sika deer is a medium-sized spotted deer native to East Asia, from Japan and China to Korea, the Russian Far East and northern Vietnam. It belongs to Cervus, the "true" deer, alongside the red deer and the elk. It has been introduced across Europe, New Zealand and parts of the United States.

Its scientific name is Cervus nippon, and the common name comes from shika, the Japanese word for deer. In Chinese it is called the "plum blossom deer," after the white spots on its back. Only three species remain in Cervus today: the sika, the red deer of Eurasia and North Africa, and the elk, or wapiti, of North America and Asia. Members of the genus can interbreed where they overlap, and the red deer is the sika's closest relative.

Sika are one of the few deer that keep their spots into adulthood. The white spots run in seven or eight rows along the upper back, though mainland subspecies have larger, bolder spots than the Japanese and Taiwanese forms, where they can be nearly invisible. The coat ranges from chestnut brown and mahogany to black, and white individuals are known. A darker stripe runs down the spine to a large white rump patch that the deer flares when alarmed, much like an elk. In winter the coat turns darker and shaggier, the spots fade, and males grow a mane.

Size varies enormously by subspecies. Overall, sika stand 50 to 110 cm (20 to 45 in) at the shoulder and measure 95 to 180 cm (35 to 70 in) in head and body, with a 7.5 to 13 cm (3 to 5 in) tail. Manchurian sika are the largest: males commonly weigh 68 to 109 kg (150 to 240 lb) and big stags reach 160 kg (350 lb). Japanese sika males weigh only 40 to 70 kg (90 to 150 lb), and females of that subspecies 30 to 40 kg (70 to 90 lb). Males are always much larger than females.

Stags carry stout, upright antlers with thick walls, usually forked at the top, measuring from 28 cm (11 in) to more than 80 cm (30 in) depending on subspecies. Females have a pair of distinctive black bumps on the forehead. Both sexes have well-developed scent glands on the lower hind legs and in front of the eyes.

Behavior and diet

Sika can be active at any time of day, but where people disturb them heavily they become largely nocturnal. In mountainous areas such as Japan, they migrate seasonally, wintering up to 700 m (2,300 ft) lower than their summer range.

They are not especially sociable. Adult males are alone for most of the year, sometimes banding together, and females with fawns group up only around the birthing season. Larger herds gather in autumn and winter.

A very vocal deer

The sika is a highly vocal deer, with more than 10 recorded sounds. Does whistle softly to each other and bleat like goats to their fawns, fawns answer with soft, horse-like neighs, and rutting males let out loud, blood-curdling screams. The alarm call may be a sharp scream, a high whistle followed by a guttural bark, or a chirp.

Diet

Sika are adaptable plant eaters that switch between grazing and browsing as conditions demand. The menu can include marsh grasses, fallen leaves, trees and brush, herbs, fungi, bamboo, ground ferns, poison ivy, soybeans and corn. They usually forage in patchy clearings within forest.

The rut

The rut peaks from early September through November and can stretch into winter. Males become territorial and gather harems. A strong prime stag may hold up to 2 hectares (5 acres), marked by scrapes up to 1.6 m (5.2 ft) wide and 0.3 m (1 ft) deep that he digs with his hooves and antlers and urinates in, leaving a strong musky smell. Fights between rivals, with antlers and hooves, can be long and fierce and are occasionally fatal.

Gestation lasts about seven months. A doe has a single fawn weighing 4.5 to 7 kg (10 to 15 lb) and hides it in thick undergrowth, where it lies quiet and still until she returns to nurse. Fawns nurse for up to 10 months, become independent at 10 to 12 months and mature at 16 to 18 months.

Escaping danger

Sika rely mostly on vigilance. Rather than fleeing as red deer do, they often hide, sometimes squatting and lying belly-flat when danger threatens. When they do run, they can bound up to 6 m (20 ft) and clear obstacles 1.7 m (5.6 ft) high. They are also excellent swimmers, recorded swimming as far as 12 km (7.5 mi) in the sea. Predators include tigers, wolves, leopards and brown bears, while lynx and golden eagles take fawns.

In Nara, Japan, sika are known as "bowing deer" because they have learned to bow their heads before being fed special crackers. A bowed head can also signal an imminent headbutt, so a person bowing to a deer may be read as a challenge.

Range and habitat

The sika is native to the temperate and subtropical forests of eastern Asia. It prefers forest with a dense understory and occasional clearings, ideally where snow stays under 10 to 20 cm (4 to 8 in), though native populations have used areas with up to 50 cm (20 in) of snow.

Japan holds by far the largest native population, which the national Ministry of the Environment estimated at 3,080,000 in 2015. China once had the most sika, but hunting and habitat loss have cut the wild population there to fewer than 1,000. Russia has a stable population of 8,500 to 9,000 Manchurian sika, confined to a small area of Primorsky Krai.

Introduced sika now live wild in much of Europe, including Britain and Ireland, as well as New Zealand, Australia and Canada. In the United States, they have been introduced in states including Maryland, Delaware, Virginia, Pennsylvania, Oklahoma, Texas and Wisconsin, as well as on Spieden Island in Washington. Many began as ornamental park animals and escaped. Unlike red deer, sika in the U.S. cannot breed with white-tailed deer or mule deer, which belong to a different genus.

Conservation status

The sika deer as a species is listed as Least Concern on the IUCN Red List, assessed in 2015. Overhunted almost to extinction in the 19th century, it recovered rapidly after protection laws in the mid-20th century. The overall picture, though, hides sharp contrasts.

In Japan, the extinction of the Japanese wolf more than a century ago and recent protection let sika numbers explode, and they now damage forests and farmland in many areas. Efforts there have shifted from conservation to control. Elsewhere, several subspecies are in trouble. The North China and Shanxi sika are believed extinct in the wild, only about 300 South China sika and just over 400 Sichuan sika remain wild, and the Vietnamese sika is extinct or nearly so.

Reintroduction is helping in places. The Formosan sika, extinct in the wild for almost two decades, was returned to Taiwan's Kenting National Park using captive animals and now numbers about 200, and similar work is under way in Vietnam. Where introduced, sika can be a problem: in Britain they hybridize with native red deer, and the European Union lists sika as an invasive species that cannot be imported, bred or released.