The fossa is active both day and night, although it seems to prefer hunting under cover of darkness. An agile tree-climber, it has short, powerful legs and retractable claws. Its long tail, the same size as its body, helps provide balance and allows it to jump from branch to branch. It spends a lot of time in the canopy, where it hunts for prey and rests between forked branches. On occasion, fossas even mate above ground.

The fossa is generally solitary except during the mating season. There is relatively little overlap in territories between individuals, with only about one adult per two square miles in drier forests. A male occupies a home range of approximately eight square miles, while a female requires about half that space.


The fossa is carnivorous and eats everything from small mammals and insects to snakes and birds. Lemurs are its preferred prey, comprising about half its diet. Often, it catches lemurs by sneaking up on them while they are asleep. Fossas have been observed hunting in teams to catch the largest lemurs. They also occasionally eat small livestock, such as chickens.

Life Cycle

The fossa’s mating season lasts from October through December. During that time females may have more than one male partner. After a gestation of six or seven weeks, females give birth to up to four young. Pups weigh about 3.5 ounces at birth and grow slowly. It takes more than two weeks for them to open their eyes. Juveniles are not independent until at least one year. It takes two years for their full teeth to come in, and can take another two years to reach full adult weight and sexual maturity. They can live around 20 years.

Some of My Neighbors

All kinds of lemurs, civets, tenrecs, spiny iguanas, Madagascar hissing cockroaches

Population Status & Threats

The fossa is classified as endangered, which means that it faces a very high risk of extinction in the wild in the near future. There are estimated to be fewer than 2,500 mature animals and their population continues to decline. Remaining populations are severely fragmented. The main threats come from habitat loss, especially logging, and the clearing of land for farming. Only 10 to 15 percent of the country remains forest. There is also a direct threat from farmers, who kill fossas because they perceive the animals as a threat to livestock.

WCS Conservation Efforts

In the mid-1990s, WCS worked with the officials in northeastern Madagascar to establish Masoala National Park, an 840-square-mile area of tropical humid forest. The dense vegetation of this region is ideal for fossas. WCS is also working with the Madagascar Ministry of Environment, Water and Forest in the adjoining Makira Forest. Conservationists are studying the interaction of humans and fossas, and working with surrounding communities to find sustainable solutions for using natural resources. Learn more about WCS work in Madagascar. 

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