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Fossa Facts: A Predator and Mongoose Relative in Madagascar

Linda Crampton is a writer and experienced science teacher with an honors degree in biology. She enjoys writing about science and nature.

The Largest Predator in Madagascar

The fossa (pronounced "FOO-sa") 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 animal is an excellent hunter and a great tree climber. It travels up and down trees and along branches with ease. It can also move rapidly over land.

The fossa was once thought to be a type of cat. 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 animal belongs to the family Eupleridae and has the scientific name 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 animal's 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.

Approximately 95 percent of Madagascar’s reptiles, 89 percent of its plant life, and 92 percent of its mammals exist nowhere else on Earth.

— World Wildlife Fund

Physical Features of a Fossa

As can be seen in the photo below, a fossa is a slender animal with an elongated body, a long tail, and a head that resembles that of a mongoose. Its body reminds some people of a weasel’s shape. The animal’s hind legs are longer than its front ones. Its hair is short and dense. Its coat is usually reddish or golden brown in colour but is occasionally black. In contrast, its belly is generally cream or light tan.

The fossa's head is quite small. It has a projecting muzzle, rounded ears, and long whiskers. The nose is bulbous and often especially noticeable. The large eyes of a fossa help it to see at night. As can be seen in the first photo in this article, the animal’s pupils contract to vertical slits in bright light. Its sharp canine teeth are helpful for attacking its prey.

Body Dimensions and Weight

The fossa's head and body have a total length of around twenty-four to thirty-one inches. The tail is often as long as the body. The animal is between fourteen and fifteen inches high at the shoulder.

Fossas weigh around fifteen to twenty-four pounds. Females are generally shorter and lighter than males. The size of one fossa in relation to a human is shown in the second video below.

The fossa belongs to the order Carnivora, like cats and mongooses. At one time, it was placed in the cat family (Felidae). It's currently placed in the family Eupleridae with the Madagascan mongooses because it’s thought to be more closely related to these animals than to cats. Some researchers still refer to the fossa as a "cat-like" animal, however.

Locomotion of the Animal

The long hind legs of the fossa enable it to leap from branch to branch in the trees. Its long tail helps it to balance as it jumps. The animal has semi-retractable claws, like those of a cat. It also has flexible ankles that can bend through an angle of 180 degrees. This ability helps the fossa to 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.

Fossas generally 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. Observers who should be reliable say that they have sometimes seen a wild fossa walk in a digitigrade fashion when it’s on the ground as opposed to when it’s in the trees.

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The fossa in the following video was temporarily anesthetized so that biologists could examine it. The animal was then released unharmed.

Diet of a Fossa

The fossa is a carnivorous animal. Its favourite food seems to be lemurs, which may be almost as large as the fossa. According to some reports, lemurs make up over half of the animal's diet. Lemurs are primates, like us. As far as scientists know, the fossa is the only animal whose primary food is a primate (if this is actually the case).

The biologist in the video above says that although fossas do eat lemurs, they also eat many other animals and are an "equal opportunity predator." The animals also eat rodents and other small mammals, birds, reptiles, amphibians, and sometimes insects. They drink water from the small pools that they find on their travels.

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 is most active at night, however.

Daily Life of the Species

Fossas are often hard to observe because they move rapidly through the tree canopy, leaping from branch to branch. This makes it difficult for biologists to learn about their lives in the wild and to get a reasonably accurate assessment of their population status. The animal is the largest carnivore in Madagascar, yet there is much to learn about it.

Some facts about the animal are known. Fossas are usually solitary. They have sometimes been observed in pairs or small groups and have occasionally been seen engaging in cooperative hunting, however. They are ambush hunters and catch prey both in the trees and on the ground.

Researchers know that the animals maintain a territory, which they mark with a secretion from their anal glands and, at least in males, from glands on their chest.

The animals communicate vocally as well as by scent. They make yelping, chirping, purring, snoring, and mewing sounds at different times, depending on the situation. They sleep in a den on the ground or in a hole in a tree.

Reproduction and Pup Facts

In the wild, fossas breed in September and October. This time of year is spring in Madagascar. 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 may mate with multiple males before she descends from her tree.

The youngsters are born in a ground den. A hollow in a tree, a rock crevice, an old and unused termite mound, or a hole in the ground are favourite sites for dens. The babies are known as pups or cubs. Between two and four pups are born after a gestation period of around two months. The reported time varies.

The pups are helpless at birth and are unable to move around. Their eyes are closed, and they have no teeth. Due to these characteristics, fossas are said to be an altricial species. The youngsters of a precocial species have relatively mature features at birth and can move around almost immediately.

The pups 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. Their lifespan in the wild is probably considerably shorter.

Masculinization in Juvenile Females

One interesting feature of the fossa's development is the transient masculinization shown by a juvenile female when she is between eight and eighteen months old. Her clitoris temporarily becomes elongated and spiny, making her look like a male. She also releases an orange or red 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. Researchers suspect that the feature may enable immature females to avoid the attention of males. Male fossas can be very assertive during the mating season.

From left to right, the meaning of the IUCN 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.

Population Status of the Fossa

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. The latest assessment of the fossa population took place in 2015. The animal was placed in the "Vulnerable" category, since its numbers are decreasing. Though it seems to have quite a wide range, it appears to have a low population throughout the range.

The main reason for the population decline is the destruction of forests in Madagascar. The land is being cleared for agriculture and logging. As a result, it has become harder for fossas to find food. Unfortunately, they sometimes prey on livestock, especially chickens, and risk being killed by farmers. In some areas, they have a bad and perhaps undeserved reputation as a nuisance or even a dangerous animal. They are sometimes hunted as a pest or killed for bushmeat.

The IUCN predicts that the fossa population will drop by around thirty percent over the next three generations. The animals can be seen at zoos in both Europe and North America and have bred in captivity. The wild population needs help, however.

The fossa is a distinctive and very interesting animal, just like much of the other wildlife of Madagascar. The country is a fascinating place with respect to its animals and plants. 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


Linda Crampton (author) from British Columbia, Canada on April 25, 2013:

Hi, Al. Wild fossas live only in Madagascar, but you may have seen an animal that escaped from captivity.

Al on April 25, 2013:

Can it be seen in West Bengal, India? As, I am sure that I saw exactly the same animal near my house here?

Linda Crampton (author) from British Columbia, Canada on February 08, 2012:

Thank you for the information, JKenny! I appreciate your comment. I'm fascinated by the fossa too. There are some very interesting animals alive today, and it's also interesting to discover as much as we can about animals of the past that no longer exist.

James Kenny from Birmingham, England on February 08, 2012:

I have also been fascinated by the Fossa, it looks a bit like a Pine Marten, but not closely related. Incidentally, there was a Giant Fossa that lived on Madagascar until 2000 years ago, it was about the size of a Leopard.

Linda Crampton (author) from British Columbia, Canada on February 06, 2012:

Thank you very much for the vote, Mike. Yes, the fossa certainly does have an unusual appearance!

MikeSyrSutton from An uncharted galaxy on February 06, 2012:

Wow great hub on a crazy looking beast! I'd love to see one live. Voted up!

Justin W Price from Juneau, Alaska on December 03, 2011:

you're welcome! Thanks again for the enlightenment

Linda Crampton (author) from British Columbia, Canada on November 07, 2011:

Hi, PDXKaraokeGuy. Yes, the fossa is a strange looking creature with an unusual name! Thank you for the vote.

Justin W Price from Juneau, Alaska on November 07, 2011:

never heard of thesse strange creatues. Thanks for sharing. Voted up and interesting. God is creative to create such strange looking beasts!

Linda Crampton (author) from British Columbia, Canada on October 16, 2011:

Thanks for the visit and the wonderful comment, epigramman! I appreciate them both very much.

epigramman on October 16, 2011:

...thank you for this education and enlightenment - your hub is worthy of National Geographic and I thank you for your research and world class presentation here.

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Linda Crampton (author) from British Columbia, Canada on October 03, 2011:

Thank you very much for the lovely comment, Eiddwen! I enjoy writing about animals, especially the less common or endangered ones. The fossa is an unusual animal, but I think that it is beautiful too.

Eiddwen from Wales on October 03, 2011:

Hi Alicia,

I thought I was well up in recognising any animal but this one is totally new to me.

I am learning so much and this Fossa is beautiful. You are an excellent teacher and another for me to Bookmark and vote up.

Thank you so much for sharing on here.

Take care


Linda Crampton (author) from British Columbia, Canada on October 01, 2011:

Hi, Nell. Yes, the fossa is fascinating. It's also very interesting that scientists think that there are many more creatures still to be discovered! Thanks for the comment.

Nell Rose from England on October 01, 2011:

Hi, what a strange looking animal, such a mixture of cats, mongoose and others, the discovery of different animals still amazes me, to think there are many out there that I haven't even heard of, the fossa is a fascinating creature, great info! cheers nell

Linda Crampton (author) from British Columbia, Canada on September 30, 2011:

Hi, Prasetio. Yes, the fossa does have some cat-like features, even though it's related to mongooses. I'd love to see a fossa in the wild. Thanks for the visit and the vote. I hope that you have a nice weekend too, Prasetio!

Linda Crampton (author) from British Columbia, Canada on September 30, 2011:

Hi, Peggy. Thanks a lot for the comment and the votes. It is a shame that the fossa population is found in such a small area.

prasetio30 from malang-indonesia on September 30, 2011:

I had never known a cat so big like this one. Thanks, Alicia for share this information. I love to learn about animal kingdom, they totally unique, like Fossa. I really enjoy your review, pictures and video. This was complete hub. Good job and vote up. Have a nice weekend!


Peggy Woods from Houston, Texas on September 30, 2011:

Thanks for educating us about this threatened species. Interesting that the fossa is only found in one place...that being Madagascar. Enjoyed this hub. Voted up, useful and interesting.

Linda Crampton (author) from British Columbia, Canada on September 29, 2011:

Hi, Maren Morgan M-T. Yes, the fossa certainly does have an unusual body shape!

Maren Elizabeth Morgan from Pennsylvania on September 29, 2011:

Interesting body shape!

Linda Crampton (author) from British Columbia, Canada on September 27, 2011:

Hi, Becky Katz. It's nice to meet you! Thanks for the comment.

Becky Katz from Hereford, AZ on September 27, 2011:

Very interesting article. I am going to have to check out some more of yours. Pretty animal.

Linda Crampton (author) from British Columbia, Canada on September 27, 2011:

Hi, Baileybear. I looked at a photo of the tree kangaroo when I read your comment. I agree, the fossa's body shape does look something like the tree kangaroo's shape! Thanks for the interesting comment.

Linda Crampton (author) from British Columbia, Canada on September 27, 2011:

Thanks a lot for commenting and for the vote, Ghost32. I hope very much that the fossa doesn't become extinct!

Baileybear on September 27, 2011:

it looks a bit like the Tree Kangaroo (from Australia)

Ghost32 on September 27, 2011:

Never heard of the fossa before now. Thanks for educating me while there are still some around!

Voted Up and More.

Linda Crampton (author) from British Columbia, Canada on September 27, 2011:

That's an excellent description of the fossa's appearance, drbj! They are strange animals. It's sad that they are restricted to one country in the wild, and that habitat destruction is putting pressure on their population. Thanks for the comment.

drbj and sherry from south Florida on September 27, 2011:

What an interesting looking animal, Alicia - with the head of a cat, the muzzle of a dog, the tail of a monkey and the body of a mongoose. It looks like something created by a committee.

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