The Fossa - A Cat-Like Mongoose Relative in Madagascar
The fossa belongs to the order Carnivora, like cats, dogs and mongooses. At one time it was placed in the cat family (Felidae), but it's now placed in the family Eupleridae. It's thought to be more closely related to the African and Asian mongooses than to cats.
The fossa is the largest predator in Madagascar. It lives in forests, both in trees and on the ground, and is active in the day or at night. The fossa (pronounced "FOO-sa") is a fierce hunter and an excellent tree climber. It travels up and down trees and along their branches with ease. It can also move rapidly over land.
The fossa was once thought to be a type of cat, but researchers have now concluded that it’s related to mongooses, despite having a body with several cat-like features and a dog-like muzzle.
The scientific name of the fossa is Cryptoprocta ferox. "Crypto" comes from the Ancient Greek word for hidden, and "procta" from the word for anus. The name refers to the fact that the animal's anus is hidden inside a pouch, which opens to the outside via a slit. "Ferox" comes from the Latin word for fierce.
Madagascar is the fossa’s only home in the wild. The IUCN (International Union for Conservation of Nature) classifies the fossa population as “vulnerable” due to the loss and fragmentation of its habitat. Animals in the vulnerable category are likely to become endangered if the factors hurting their population size aren’t changed.
Location of Madagascar - The Home of the Fossa
Animals are categorized based on the time when they are most active. Nocturnal animals are active during the night, diurnal animals during the day, crepuscular animals at dawn and dusk and cathemeral animals - such as the fossa - at any time.
The Fossa's Body
A fossa is a slender animal with an elongated body and a long tail. The fossa's coat is usually a reddish or golden brown colour but is occasionally black. The belly is generally cream. The animal has a projecting muzzle, rounded ears, a bulbous nose and long whiskers. Its large eyes help it to see at night.
The fossa's head and body have a total length of around twenty-four to thirty-one inches. The long tail is about the same length as the head and body. Fossas weigh around fifteen pounds to twenty-five pounds. Females are generally shorter and lighter than males
A fossa’s hind legs are longer than its front legs, which enables the animal to leap from branch to branch in the trees. Its long tail helps it to balance as it jumps. A fossa has semi-retractable claws, like those of a cat. It also has flexible ankles, which can bend through an angle of 180 degrees and help it cling to tree branches and walk head first down tree trunks. Fossas in captivity have been observed hanging upside down from ropes with just their hind feet attached to the rope. They walk on the soles of their feet, as we do, which is known as a plantigrade method of locomotion. Cats and dogs walk on their toes and are said to have digitigrade locomotion.
The Fossa - An Amazing Predator
The Life of a Fossa
Fossas are usually solitary animals. They are often hard to observe because they move so rapidly through the tree canopy, leaping from branch to branch.
The fossa is a carnivorous animal. Its favourite food is lemurs, which may be almost as large as the fossa. Lemurs are believed to make up over half of the animal's diet. As far as scientists know, the fossa is the only animal whose primary food is a primate. Fossas also eat rodents, birds, reptiles and sometimes insects. They hunt both in the trees and on the ground. They sleep in a den on the ground or in a hole in a tree.
Fossa maintain a territory, which they mark with a secretion from their anal glands and, at least in males, from glands on their chest. They are generally seen on their own. Occasionally fossas have been observed in pairs or small groups, however. They have sometimes been seen engaged in cooperative hunting.
Fossas communicate vocally as well as by scent. They make yelping, chirping, purring, snoring and mewing sounds at different times, depending on the situation.
A Baby Fossa in a Zoo
In the wild, fossas breed in September and October. Mating usually takes place in specific trees that are used each year, although it has also been observed taking place on the ground. A female may stay in her mating tree for up to a week and attract many males. The mating process may last for up to an hour or more per male. The female usually mates with multiple males before she descends from the tree.
The youngsters are born in the trees or in a ground den. A hollow in a tree, a rock crevice, an old termite mound or a hole in the ground are favourite sites for dens. Between two and four babies are born after a gestation period of two to three months. The babies are weaned at about four months old. They stay with their mother for at least twelve months and are ready to mate at around four years of age. Fossas in captivity live for about twenty years.
One interesting feature of the fossa is the transient masculinization shown by a juvenile female. Her clitoris temporarily becomes elongated and spiny, making her look like a male. She also releases an orange secretion on her undersurface like a mature male. By the time she reaches adulthood these features have disappeared. The reason for the female's temporary masculinization is unknown.
Fossa Enrichment Activity in a Zoo
From left to right, the meaning of the red list categories shown above is as follows.
- EW - Extinct
- EW - Extinct in the Wild (but still exists in captivity)
- CR - Critically Endangered
- EN - Endangered
- VU - Vulnerable
- NT - Near Threatened
- LC - Least Concern
Often two additional categories are added on the right - DD, or Data Deficient, and NE, or Not Evaluated.
The Fossa Population
The IUCN maintains a “red list” of threatened animal species. Each species that has been assessed is assigned to a red list category based on its nearness to extinction. In the latest version of the red list the fossa population is classified as vulnerable, since its numbers are decreasing.
The main reason for the decline of the fossa population is that the forests in Madagascar are being destroyed for agriculture and logging. As a result, fossas sometimes prey on livestock, especially chickens, and risk being killed by farmers.
In some areas fossas have a bad and perhaps exaggerated or undeserved reputation as a nuisance or even as a dangerous animal. They are sometimes hunted as a pest or are killed for bushmeat.
Fossa have bred in captivity, but their population in the wild is under stress. They can be seen at zoos in both Europe and North America.
The fossa is a distinctive and very interesting animal, just like much of the other wildlife of Madagascar. I hope that ways can be found to balance both the needs of humans and the needs of wildlife on the island.
© 2011 Linda Crampton
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