Capricornis crispus

225.

Japanese Serow

Capricornis crispus

French: Serow du Japon / German: Japan-Serau / Spanish: Sirao de Japén

Taxonomy. Antilope crispa Temminck, 1844,

Japan.

Sometimes considered conspecific with the Formosan Serow (C. swinhoei) but mtDNA data support classifying C. crispus and C. swinhoe: as separate species. Monotypic.

Distribution. Japan on Honshu, Shikoku, and Kyushu Is.

Descriptive notes. Few measurements available. Tail c.6-8 cm, shoulder height 68-78 cm (males) and 68-80 cm (females); weight 31-48 kg (males) and 33-44 kg (females). Horn length 12-16 cm (males), 12-15 cm (females). Sexual dimorphism is minimal. Body coloris whitish, grayish, black, or black with a white dorsal spot and dark dorsal stripe. Long hair covers the tail and body; there is a whitish upper neck ruff of long and fluffy hair; belly whitish, cheeks and lips white, area around eye and preorbital gland and crown of head also white, and legs blackish-brown. Diploid chromosome numberis 50.

Habitat. Cool forest zone, principally in temperate deciduous forest with more than 80% forest cover; terrain rugged, mountainous; occurs from sea level to about 2700 m above sea level. The Japanese Serow also occurs in broad-leaved evergreen forest, subalpine coniferous forest, alpine meadow, mixed deciduous and conifer forest, and coniferous plantations. Its distribution can be patchy because ofits proclivity for endemic primary forest. Mature forests are also important movement corridors. Number and size of territories and vegetation cover in relation to forage quality, variety, and quantity have the greatest influence on population density.

Food and Feeding. The Japanese Serow is basically a browser, feeding on a variety of deciduous and coniferous trees and shrubs and bamboo, but forbs and grasses can be seasonally important. Diet in one area was 42-5% green broad leaves;it was 65-2% total browse during winter. Weight loss in November—March was greater for older females (about 20%) than males (5%) and greater in non-pregant females (23%) than in pregnant females (15%).

Breeding. Most females reach sexual maturity at 2-5-4-5 years of age. Considered monogamous; during a 24year study, 71:3% of mating units were monogamous, 25% consisted of one male and two females, and 3-:8% were one male and three females. The mean sex ratio was 70 males: 100 females and the mean ratio of offspring to adult females was 83 offspring:100 females. Mating occurs in September—January. Gestation is 210-220 days, and parturition peaks in May-June. Twinning is rare; only two of 259 pregnant females had twins. Newborns weigh 3.3-3.7 kg. Estimated life expectancy at birth is 4-8-6-5 years and longevity is up to 25 years.

Activity patterns. Primarily diurnal, but with both diurnal and nocturnal feeding periods.

Movements, Home range and Social organization. The Japanese Serow is basically solitary, but it occurs in groups of up to four. Sixty-two percent of groups consisted of one adult female and her offspring (up to two years old) and 74% of groups were of 2—4. Other groupings included mother—offspring—adult male (27%) and adult male-adult female (18%). Average population density was 1:7-1-9 ind/km? for 71 study sites. In anotherstudy site, densities were 10-2-15-6 ind/km* based on seasonal estimates. Density seldom is greater than 20 ind/km? Higher densities occur in primary forest, but after logging and reforestation, densities can greatly increase due to increase in forage availability. Serow densities decrease when trees in the afforested area mature. In an area where clear cuttings were patchily distributed, mean annual home ranges were 13-8 ha (1:6-33-5 ha) for males and 9-3 ha (1-2-33-5 ha) for females. Male and female adults maintain intrasexual territories. Behaviors related to territoriality include scent marking with preorbital glands, object aggression, optical marking by standing still, sometimes on stumps and large rocks to emphasize their presence, and defecating on dung piles. Yearlings remain within their mother’s territory. Offspring leave the natal territories to establish their own territories when they near sexual maturity. Adult males were aggressive to male offspring that were one year old or older but tolerant of female offspring. Three percent of offspring remained within their natal home range and 91% dispersed. Age at dispersal was 2—4-5 years for males and 2-4-3 years for females. Territories within an area can be established by serows born in the area, immigrants from outside the area, and by former territory holders. During a 24year study, the mean duration ofterritory retention was 11-7 years for females and 12-4 years for males. Males had larger territories (20-4-22-8 ha) than females (6-9-14-1 ha). Adult mortality from native predators and feral dogs is negligible,as is potential competition with exotic deer.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Total population is 100,000. Populations in general are stable or increasing. Limited hunting outside of protected areas is allowed to limit damage to tree plantations by Japanese Serows. Monitoring and management programs should be implemented and an expanded number of protected areas that provide mature native forests and movement corridors need to be established.

Bibliography. Doi et al. (1987), Groves & Grubb (2011), Jass & Mead (2004), Jiang Zhaowen et al. (2008), Kishimoto (1987, 2002), Komori (1987), Maita (1987), Maruyama et al. (1997), asui (1987), Min Mi-Sook et al. (2004), Miura & Maruyama (1986), Miura et al. (1987), Ochiai (2009), Ochiai & Susaki (2002, 2007), Okumura (2004), Soma et al. (1987), Tokida (2008).