Family break-up in Japanese serow, Capricornis crispus

Abstract

Ungulates have a gradational social organisation from a solitary life or monogamous pairs to large gregarious groups. This gradation of social organisation has been pointed out to be correlated with a shift in habitats from closed forest to open grassland or savannah (Estes 1974, Jarman 1974). The dissolution of the mother-young bond, otherwise called family break-up, is presumed to be related to the social organisation of the species, and possibly to the sex of the young. However, family break-up has not been well documented so far, especially in mountain ungulates, because long-term observations of identified individuals are required. The Japanese serow Capricornis crispus usually lives alone, and sometimes forms male female pair units or family groups with up to four individuals (Akasaka and Maruyama 1977, Kishimoto 1981, Sakurai 1981, Ochiai 1983b). In the Japanese serow, the process of reaching independence by offspring has been documented (Ochiai 1983a), but there is not enough information on territory establishment by independent offspring. This chapter aims to describe the process of reaching independence, and that of territory establishment of offspring in the Japanese serow, based on continuous observations in the wild for seven years.