Binturong

Name and taxonomy

Thomas Stamford Raffles described the species in 1822 from an animal taken at Malacca in Malaysia. He placed it in the genus Viverra, with the true civets. Coenraad Jacob Temminck created the genus Arctictis for it in 1824. The genus name joins two Greek words, one for bear and one for weasel. The word binturong comes from Malay, and older roots in the region mean a squirrel and a creature that climbs down.

The binturong is the only species in its genus. Zoologists have named nine subspecies, from Yunnan in China to Java and the island of Palawan. The Palawan form, whitei, is the one most often studied in the field. It sits in the family Viverridae, in the subfamily Paradoxurinae with the palm civets.

Evolution and relatives

The subfamily Paradoxurinae holds four living genera. Genetic work dates its origin to between 35.5 and 21.9 million years ago. The small-toothed palm civet, Arctogalidia, split off first. The binturong line separated about 15.9 million years ago, before the masked palm civet and the Asian palm civets.

The species has two genetic groups, a northern one in Indochina and a southern one in the Sunda region. The Isthmus of Kra separates them today. During the Pleistocene the animals probably moved across a land bridge, and rising seas later cut the two groups apart. Three subspecies belong to the northern group and six to the southern group.

Appearance

The binturong has a long, heavy body on short, thick legs. The head and body measure 61 to 96 centimetres, and the tail adds 56 to 89 cm. Adults weigh 9 to 20 kilograms. Females are larger than males, by about 20 percent, and they dominate the males they meet. The coat is coarse and black, and many animals carry white or buff tips that give a grey or straw look.

The face has a short, pointed snout and long white whiskers. The ears are small and round, with a white rim and a black tuft of hair on top. The tail is thick and muscular at the base and curls inwards at the tip. The feet are flat-soled, with five clawed toes, and the third and fourth toes are joined. The jaws hold 36 to 40 teeth, and the canines are long and sharp. Unlike most carnivorans, the male has no penis bone.

Habitat and range

The range runs across South and Southeast Asia. It includes India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Laos, Cambodia, Vietnam, southern China, Malaysia, Indonesia and the Philippines. In Indonesia the animal lives on Sumatra, Java and Borneo, and on smaller islands such as Nias and Bangka. In the Philippines it occurs only on Palawan. GBIF holds records from 16 countries, though some of those are zoo animals.

The binturong lives in tall, dense tropical forest and spends most of its time in the canopy. It ranges from sea level up to about 3,000 metres, but lowland primary and secondary forest hold the most animals. In Assam it prefers wooded hills and foothills to the forested plains. In Laos it uses large tracts of evergreen forest. On Palawan it lives in lowland forest and in a mix of grassland and forest up to 400 metres. It can survive in logged forest, and in Malaysia it has been recorded in regrowth beside an oil palm estate.

Diet and feeding

The binturong belongs to the order Carnivora, but it eats mostly fruit. Figs are the main food, and the fruit of the strangler fig Ficus altissima is a favourite. It also takes small mammals, birds, eggs, insects, earthworms, carrion, shoots and leaves. It has been seen swimming and diving for food, and fish appear in the diet. Fish and worms are probably rare meals, because the animal neither swims for a living nor digs.

The binturong is a keystone species in its forest. Its gut can soften the hard coat of a strangler fig seed, so the seed sprouts after it passes through. No other animal is known to spread the seeds of Ficus altissima. As a hunter of rodents, it may also hold down the numbers of its prey.

Behaviour and social life

The binturong lives alone for most of the year. Neighbours avoid each other, but they do not defend a fixed territory. Home ranges overlap by about 35 percent on average. In Thailand the mean annual range was 6.2 square kilometres. A female in Khao Yai National Park used about 4 square kilometres, and males there used 4.5 to 20.5.

The animal is active mainly at night and around dusk and dawn. Five radio-collared animals in Phu Khieo Wildlife Sanctuary peaked in the early morning and late evening and rested in the afternoon. Daytime sightings do occur, for example in Pakke Tiger Reserve in India. The collared animals walked as little as 25 metres a day in the dry season and up to 4,143 metres in the wet season.

The binturong climbs slowly and carefully, and it seldom jumps. It walks along the top of a branch or hangs beneath it, and the tail holds on as a fifth limb. The hind feet can turn backwards, so the claws grip a trunk while the animal comes down head first. It is too heavy to leap between crowns, so it often descends and crosses the ground with a flat-footed walk. At rest it curls up with its head tucked under its tail.

Communication and senses

Scent is the binturong's main way of sending a message. Both sexes have glands beside the anus, and the female has a second pair beside the vulva. The animal drags its tail and rear over branches as it climbs, and the marks tell others where it has been. The famous popcorn smell comes from the urine, which contains 2-acetyl-1-pyrroline, the same compound formed when popcorn pops. A study at Duke University found none of that compound in the gland secretion itself. The oily musk from the glands helps the scented urine stick to bark and last in the humid canopy.

The binturong also uses its voice. It growls when annoyed, and it grunts or hisses through half-open lips as it moves. An angry animal screams, howls or cackles, and a content one makes a chuckling sound. A female in oestrus purrs loudly during mating. The pupils are elliptical and open wide, so the eyes work in both bright and dim light.

Reproduction and life cycle

Most of what is known about breeding comes from zoos. The animals mate in any month, but more births fall between January and March. A female can delay implantation, so a fertilised egg waits until food and weather are right. When the female is not receptive she keeps away from males, and the males act defensively towards her. In oestrus she calls to attract a mate, and mating takes place up in the canopy.

Gestation lasts about 91 days, with a reported range of 84 to 99 days. A litter holds 1 to 6 young, and 2 is typical. Zoo keepers call the newborns binlets. They are born blind and helpless and hide in their mother's fur for the first days. Weaning comes at 6 to 8 weeks. Females mature at about 30 months and males at about 28 months.

The mother cares for her young until they can fend for themselves, and daughters may stay with her afterwards. One zoo report describes a father that stayed with the mother and young, so some pairs may be monogamous. Wild animals live up to 18 years, and captive ones up to 25.

Predators and threats

Few animals can kill an adult binturong. Tigers and dholes take one now and then. In one study, 172 dhole scats from binturong country held no trace of the species. The thick, coarse coat makes a clean bite hard to land. The strong smell warns other animals that a large, well-armed civet is near. A cornered animal may urinate or defecate on the threat, then bite with the skull and jaws of a true carnivore.

People are the real danger. Logging and the conversion of forest to plantations have destroyed much of the lowland habitat, above all in the Sunda region. Hunters take the animal for meat, for skins, and for traditional medicine. Young animals are caught for the pet trade, and some are kept to produce kopi luwak coffee. Degraded forest can still hold binturongs, but it also brings more hunters.

Population and conservation

The IUCN Red List classes the binturong as Vulnerable. The population fell by more than 30 percent over 30 years. No one appears to have a good count of the animals left in the wild. The China Red List classes it as Critically Endangered, and Malaysia and Myanmar protect it by law.

CITES lists the species in Appendix III, at the request of India. Zoos breed the animal, but a 2006 study found low genetic diversity in the captive stock. Poor records of origin risk inbreeding or the mixing of subspecies. Since 2016 the charity ABConservation has run the Bearcat Study Programme on Palawan to track wild animals. Conservationists ask for stronger action against poaching and forest loss.

Relationship with humans

Zoos across the world keep binturongs for education and display. Visitors often notice the popcorn smell before they see the animal. In the wild the species eats rodents, which helps farmers near the forest. Its meat is a delicacy in some countries, and its fur is traded.

The animal is said to tame easily, and some people keep it as a pet. It is shy by nature and rarely attacks a person. A harassed animal can bite hard, and its scent is hard to wash out. Captured young feed the pet trade, so a pet probably costs a wild mother her cub.

In culture and myth

Early English writers named the animal bearcat, since its walk reminded them of a bear and its face of a cat. Old travel books cast it as a strange tree-bear of the rainforest canopy. Zoo keepers speak of its smell as a forest perfume that tells you an animal is close. The names in Thai, Chinese and Malay seem to describe a bear, a cat or a civet, and none of them names a myth.

A general animal blog suggests some forest peoples treat the binturong as a sacred guardian of the trees and a bringer of luck. That claim names no culture, so it is probably best read with care. In parts of Indonesia and the Philippines the animal is said to be a symbol of good fortune. In the United States the bearcat is a sports mascot at Binghamton University and the University of Cincinnati. The artists give those mascots the body of a bear and the face of a cat, not the look of a civet. ABConservation marks World Binturong Day on the second Saturday of May.