The biology and status of Owston's palm civet in Vietnam
Nguyen Xuan Dang, Pham Trong Anh and Dang Huy Huynh
Ecology and biology
Owston's palm civet (Chrotogale owstoni Thomas, 1912), is one of the rarest members of the viverrid family in Vietnam and a critically endangered species worldwide.
It is a very beautiful animal (Fig. 1). The brown pelage has four large triangular black bands crossing the back, and two black bands running along the shoulders on each side. The long tail has two complete brown rings at its root, the rest being completely black. Chrotogale is a medium-sized viverrid with a head and body length of 560 to 720 mm, a tail length of 350 to 470 mm, and an ear length of 40 to SO mm. The body weight is between 2,500 and 4,000 g.
Very little is known of the ecology and biology of the species. It prefers humid habitats: valley forests, hillsides, foothills with streams, lakes, and the headwaters of rivers. They also inhabit the shrubby surroundings of forests, bushland along river banks and even scrub near cultivated fields. Chrotogale makes simple dens under large tree-trunks or in dense bushes (Le Hien Hao, 1973; Pham Trong Ahn, 1982). They also frequently use natural holes in trees, rocks, or in the ground for nesting and resting. These dens are not used for long periods of time, they often change dens in response to the availability of food resources and changing seasons.
Owston's palm civet is terrestrial but can climb very well. In their search for food they often climb trees to prey on small animals (birds, lizards, insects, etc.) or to take fruits. Being nocturnal they remain in their den during the day. Emergence time depends on the security of the habitat, the food supply, and their physiological status. Usually activity commences at dusk and ends early in the morning. Sometimes they may go out late in the afternoon at sunset. Pregnant and lactating females often become active later than the others (Le Hien Hao, 1973). They are most active between 21.00 h and 24.00 h (Pham Trong Anh, 1982). Our observations of captive specimens revealed that they were active for between 7 and 10 hours per day. During daytime they usually only leave their dens for a few minutes, either to drink or urinate. Activity begins begins between 17.00 h and 20.00 hours and ends between 04.00 and 06.00 hours the next day. During the activity period, rests lasting between 30 min to 2 h are taken. Subadult animals are active for longer than adults. Food is usually searched for in forest surroundings, along rivers, and in cultivated fields. Sometimes they may take poultry from local villages.
Owston's palm civet marks its home territory with the secretions from scent glands located in both sexes' ano-genital region. Whilst moving the animal suddenly stops, lowers hidher pelvis and touches the ground, tree, etc. with the ano-genital region, after which the animal stands up quickly and moves on. The frequency of marking increases when the animal enters new territory, or when an unfamiliar animal enters their territory. They habitually defecate and urinate at the same spot near the den.
According to Le Hien Hao (1973) and Pham Trong Anh (1982), Clzrotogale is solitary except during the breeding season. Our captive specimens live in social groups of two or three females, or in mixed-sex groups. Moreover, the animals usually lie side by side or even on top of one another. They appear of a peaceful disposition; readily accepting new members to their group without any show of aggression or fighting.
Owston's palm civet is usually silent but can produce a sound similar to that of a domestic cat. The diet is specialized, consisting mainly of earthworms plus a small percentage of other small animals and fruits. Stomach contents'revealed that earthworms may make between 65 to 100% of the total contents (Le Hien Hao, 1973; Pham Trong Anh, 1982). Earlier research also found eathworms in the stomach contents (Nowak & Paradiso, 1983; Dao Van Tien, 198.5). Other prey items include amphibians, birds, rats, eggs, and insects (locusts, crickets, cockroaches). In captivity our animals willingly take earthworms, lean beef, chicken, frogs, small birds, eggs, and insects. Of all the fruits given, they prefer bananas and chiku fruit (Manilkara aclzras). It was estimated that an adult animal can eat about 100 g meat (beef, chicken, earthworms) and 200 to 300 g of fresh fruit per day.
Chrotogale has one or two litters per year, each consisting of one to three kits. The gestation period lasts about 60 days (Le Hien Hao, 1973). The mating season appears to be mainly from January to March, but breeding may last until November. Le Hien Hao (1 973) described fully-grown embryos as having a total length of 180-193 mm and a weight of 75-88 g, with a pelage similar to the adult’s. A newborn female of about 3-4 days old looked helpless, had closed eyes, and had a total length of 190 mm, a tail of 110 mm and a body weight of 86 g.
Status and conservation
The distribution of Owston’s palm civet is confined to a very small area in Asia that includes northern Vietnam, northern Laos, southern Yunnan and southern Guangxi in China (Schreiber et al., 1989). In Vietnam the species has been found in most of the northern provinces (Fig. 2), but always in low numbers (Le Hien Hao, 1975; Pham Trong Anh, 1982; Dao Van Tien, 1985).
Habitat loss and disturbance and intense hunting pressure during the last few decades have eliminated much of their former range and critically reduced the number of animals.1n Vietnam Chrotogale is protected by law as an endangered species and listed on the “Checklist of National Endangered Species” and the “Red Data Book of Vietnam”.A number of nature reserves have been gazetted in their range, but the Cuc Phuong National Park is the only reserve where the occurrence of the species is occasionally recorded.
At present, evidence for the occurrence of Owston’s palm civet comes only from the provinces of Lai Chau, Na Son Binh, and Son La, and the Cuc Phuong National Park. In the mean-time, habitat loss, disturbance, and intense hunting pressure still remain immediate threats which could lead the species to extinction in the near future.
Since 1990 the Institute of Ecology and Biological Resources, NCSR of Vietnam, has started to implement the “Programme of Conservation and Restoration of Owston’s palm civet in Vietnam”. The aims of this Programme are:
- to assess the exact status and distribution of the species in Vietnam
- to elaborate recommendations relevant to the conservation and restoration of the species
- to select suitable sites for the establishment of Chrotognle reserves
- to establish a captive population in Vietnam for reintroduction in well-managed reserves. The first attempt at captive breeding has been conducted (Nguyen Xuan Dang et al., 1991)
- to study the biology and ecology of the species
- to seek international cooperation in the conservation and restoration of the species in Vietnam
References
Dao Van Tien. 1986. Scientific results of some mammal surveys in North Vietnam (1 957- 197 1). Sci. & Tech. Hanoi. 340 pp. (In Vietnamese, English summary).
Le Hien Hao. 1973. Economic mammals of North Vietnam. Sci. & Tech. Hanoi, 1 :224-229. (In Vietnamese)
Nguyen Xuan Dang, Pham Trong Anh, Ngo Bich Nhu & Le Chan. 1991. Owston’s palm civet, Chrotogale owstoni, in captivity. Mustelid & Viverrid Conserv., 4:7-8.
Nowak, R. M. & Paradiso, J. L., eds. 1983. Walker’s inainmals of the world. John Hopkins Univ. Press, Baltimore + London.
Pham Trong Anh. 1982. Study of carnivore nzaininals (Carnivora) in North Vietnam. Doctoral Dissertation Hanoi. Pp 129-195.
Schreiber, A., Wirth, R., Riffel, M. & Van Rompaey, H. 1989. Weasels. civets, mongooses, and their relatives. An Action Plan for the Conservation of Mustelids and Viverrids. IUCN, Gland. 99 pp.
Institute of Ecology and Biological Resources, NCSR Vietnam, Nghia do-Tu Liem, Hanoi, Vietnam |
