The clouded leopard is frequently described as bridging the gap between big and small cats. It has proportionately short legs and a long, bushy tail. The coat is brown or yellowish-gray and covered with irregular dark stripes, spots, and blotches. Black and pale, whitish individuals have been reported from Borneo. Clouded leopards have long canine teeth with very sharp posterior edges. DNA comparisons suggest that the clouded leopard is most closely related to the extinct saber-tooth cat of North America, Smilodon fatalis. Although larger than other "small" cats, the clouded leopard does not roar like the larger cats. Clouded leopards weigh 35 to 50 pounds (15.8 to 22.68 kilograms) and measure ten to 16 inches (25.4 to 40.6 centimeters) high at the shoulder.
The clouded leopard has recently been divided into two species of cats based on DNA analysis. Those two species can also be divided geographically into mainland cats and island cats. N. nebulosa are the mainland cats ranging throughout Nepal, Bangladesh, eastern India through Indochina, northeastward to southern China and, formerly, in Taiwan. The island cats, N. diardi, live in Sumatra and Borneo. Although population numbers are thought to be lower outside protected areas, their populations are probably healthiest in Borneo because there aren’t any tigers or leopards there. Surveys there suggest a density of one individual per 1.5 square miles (4 square kilometers). See range map for N. Nebulosa (mainland) See range map for N. diardi (island)
Based on anecdotal observations, scientists originally thought clouded leopards preferred to live in evergreen tropical rainforests. More recent sightings suggest they also live in other types of habitat, including secondary and logged forest as well as grassland and scrub. In Borneo they are reported in mangrove swamps and in Nepal they are found at least as high as 4,757 feet (1,450 m), and perhaps as high as 9,843 feet (3,000 m).
Clouded leopards eat mainly monkeys, small deer, and wild boars, which it ambushes from the trees or stalks from the ground. They may also hunt birds, rodents, and domestic poultry.
Because the clouded leopard is such a secretive animal, with most sightings made at night, most of the knowledge of its social behavior comes from observations in zoological facilities. Once paired as young, most clouded leopards in captivity remain with the same mate for life. Unlike other large cats, however, pair formation is virtually only successful if it happens before the clouded leopards are one year old. Formation of adult pairs, at least in captivity, often results in the male injuring or killing the female. Females bear two to four young after a gestation of 93 days. The young reach independence in less than one year.
The clouded leopard's arboreal talents rivalS those of the margay of South America. In captivity, they run down tree trunks headfirst, climb along horizontal branches with its back to the ground, and hang upside down from branches by their hind feet. However, there is no field evidence to support the assumption that they spend most of the life in trees. It now appears that they use trees primarily as resting sites and that clouded leopard movements are typically terrestrial. In Malaysia, it is known as the “tree tiger.” Interestingly, they also appear to swim well and have been found on small islands off Borneo and Vietnam. In Borneo they may be more diurnal, presumably because of the absence of other large carnivores.
Clouded leopards are frequent victims of habitat destruction and illegal hunting. Clear cutting of forests for use as agricultural lands is its primary threat, as the clouded leopard needs large tracts of forest for hunting. They are widely hunted for their teeth, decorative pelt, and bones for the traditional Asian medicinal trade. Their pelts are still reported on sale in urban markets of Burma, Laos, Vietnam Cambodia, Nepal, and Thailand. They are also featured on restaurant menus in Thailand and China that cater to wealthy Asian tourists. The primary threat to Sunda clouded leopards is the expansion of palm oil plantations. Borneo and Sumatra are experiencing the world’s highest deforestation rates.
The IUCN classifies clouded leopards as vulnerable. The U.S. Fish and Wilfdlife Service lists them as endangered, and they appear on CITES Appendix I. Although officially protected in most range countries, enforcement is weak in many areas. Precise population data in the wild is unknown, but the reduced number of pelts appearing at fur markets and sightings of live clouded leopards by resident peoples within its range suggest the species is declining. There are four recognized subspecies; the subspecies that is restricted to Taiwan, N. n. brachyurus, is thought to be extinct.
Clouded leopards are considered one of the most difficult large cats to breed in zoological facilities. Priorities for this Species Survival Plan include increasing the number of founder animals of known origin, identifying the relationship of clouded leopard subspecies, and developing a protocol for the introduction of new breeding pairs. The target population of the Regional Collection Plan is 120 animals.