The unusual-looking fossa (Cryptoprocta ferox) 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.
The fossa has a slender body and muscular limbs, and a tail nearly as long as the rest of the body. It has a mongoose-like head, relatively longer than that of a cat, although with a muzzle that is broad and short, and with large but rounded ears. It has medium brown eyes set relatively wide apart with pupils that contract to slits. Like many carnivorans that hunt at night, their eyes reflect light; the reflected light is orange in hue. Both males and females have short, straight fur that is relatively dense and without spots or patterns. Both sexes are generally reddish-brown dorsally and colored a dirty cream ventrally. When in a rut, they may have an orange coloration to their abdomen from a reddish substance secreted by a chest gland, but this has not been consistently observed by all researchers. The tail tends to be lighter in color than the sides. Juveniles are either gray or nearly white.
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 in Madagascar, from mountainous areas down to the coastal lowlands.
The fossa is a solitary mammal that patrols territory as extensive as four square kilometers, marking its presence with scent from its anal gland. It is active during both the day and the night and is considered cathemeral; activity peaks may occur early in the morning, late in the afternoon, and late in the night. The fossa spends most of its time high in the trees but does move about and hunt down on the ground too. During the day they usually rest in a cave, hollow tree, or abandoned termite mound. 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. Fossas communicate using sounds, scents, and visual signals. Vocalizations include purring, a threatening call, and a call of fear, consisting of "repeated loud, coarse inhalations and gasps of breath". A long, high yelp may function to attract other fossas.
Fossas are carnivores. They eat small mammals, birds, amphibians, reptiles, and insects. They will also prey on lemurs.
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 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 the 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 among the main reasons for the decline in the fossa population, with 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 in 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 in Madagascar, impacting the numbers of many species of small birds, mammals, reptiles, and amphibians that they eat.
