The unusual-looking fossa from Madagascar looks like a puma and has both canine and feline features. It is the largest mammalian carnivore on the island, and preys mainly on lemurs, pursuing them through the trees with remarkable speed and agility. The fossa is renowned for its appearance, its strength, and its peculiar mating rituals. It is declining due to habitat loss and fragmentation. The reserves where it currently lives are not large enough to support a manageable population, and urgent measures are necessary to secure the future of this unique mammal.
Endemic to Madagascar, fossas are found throughout the island, though in the Central Highlands, it is only in certain areas, like the Andringitra Massif. This species inhabits all forested areas on Madagascar, from mountainous areas down to the coastal lowlands.
The fossa is a nocturnal and solitary mammal that patrols a territory as extensive as four square kilometers, marking its presence with scent from its anal gland. It spends most of its time high in the trees but does move about and hunt down on the ground too. These animals are remarkably agile at both leaping and climbing, with great help from their long, slender tail. Because they move from place to place on their flat soles, this gives them more stability and balance when making precarious landings on branches. Although largely nocturnal, fossas also hunt in the day, especially when food is scarce, but usually they rest during the day in a cave, hollow tree, or abandoned termite mound.
Fossas have a most unusual mating system. Mating takes place from September to October. A female will occupy a site on her own, high in a tree, and a number of males will congregate below, and compete for mating rights. Over the period of a week, the female mates with several of the males. Once she has left the site, another female takes it over the site and also mates with several of the males. This means fossas may have a polyandrous mating system. Such ‘mating trees’ are used over many years. 2 to 4 young are born about three months later, are blind and helpless when born, and weigh about 100 g. Weaning takes place at about 4-5 months, but young remain with their mothers until the age of 15-20 months. Observations of captive individuals indicate that sexual maturity is reached at the age of 4 years.
Habitat loss is amongst the main reasons for the decline in the fossa population, fragmented populations becoming isolated in the forest patches that remain. However, the most important threat to their survival is probably local farmers, who see fossas as significant predators of poultry.
The fossa is widely distributed on Madagascar but it is very scarce and rare in most areas. According to the IUCN Red List the total fossa population size is between 2,635 and 8,626 adults. Currently this species is classified as Vulnerable (VU) and its numbers continue to decrease.
A fossa is the top mammalian predator on Madagascar, impacting the numbers of many species of small birds, mammals, reptiles, and amphibians that they eat.