Fossa

Facts

IUCN VULNERABLE (VU)

Facts about this animal

The fossa is extremely cat-like in appearance. It possesses an elongated body, measuring approximately 1.3 to 1.5 m in length from head to tail. Some sexual dimorphism is observed with females slightly smaller than males. The average weight is 6.75 kg though males of up to 10 kg have been reported from the wild. It has a short reddish-brown coat that fades to a lighter colouration on the underparts. They have large eyes, reflecting their cathemeral activity pattern, being both day and night active. They have a large bulbous nose and pronounced whiskers. Overall their body is heavily muscled.

Fossa are extremely adept at climbing trees, their large, hairless footpads allowing them to get a better grip on branches, with their long tail also acting as a balance organ. Their hindlimbs are longer than their forelimbs, enabling them to leap from branch to branch. They have semi-retractile claws.

Their cat-like dentition reflects their highly predatory nature, being entirely carnivorous. They are the only species studied to date whose primary prey is a primate. In studies from the western dry forests more than 50% of the diet of fossa, ascertained from scats, was found to be large, diurnal lemurs. They appear to preferentially hunt at night and can take prey of over 5 kg, including the Indri, the largest of the extant Malagasy primates.

The fossa is solitary and appears to require a large home range (up to 20 km² for males). Females require less area but appear highly territorial in relation to other females. Occassionaly males are observed together and male home-ranges overlap other males and females.

Their reported mating system is highly unusual. They have a multi-male mating system wherein females take up residence in a 'mating tree' for up to a week once a year. Males then compete with other males to gain access to the tree. Over a week the female may mate with up to 6 males. These matings can be very prolonged, lasting more than a hour. Gestation is approximately 56 days and 2-4 kittens per litter will be produced.

Did you know?
that the fossa has extremely unusual genitalia? In females this is due to the occurrence of transient genital masculinisation, observed in youngsters between 8 and 18 months. In these young females the clitoris becomes masculinised, becoming far more prominent and elongated. Small hard spines also develop and cover the clitoris, mimicing the appearance of the penis in the male. The groin area also takes on a reddish colouration, usually observed in the male.

Factsheet
Class	MAMMALIA
Order	CARNIVORA
Suborder	FISSIPEDIA
Family	VIVERRIDAE
Name (Scientific)	Cryptoprocta ferox
Name (English)	Fossa
Name (French)	Foussa, Fossa Cryptoprocte
Name (German)	Frettkatze, Fossa
Name (Spanish)	Gato fossa de Madagascar
Local names	Malagasy: Fosa, Kintsala, Tratraka
CITES Status	Appendix II
CMS Status	Not listed

Photo Copyright by
Trisha Shears

Distribution

Distribution
Range	Madagascar
Habitat	The fossa is found ranging over much of the Indian Ocean island of Madagascar, wherever there is sufficient remaining tree cover to survive.
Wild population	Approx. < 2,500 (2005) (Red List IUCN 2011)
Zoo population	98 registered by the International studbook (2004), 69 reported to ISIS (2005)

In the Zoo

How this animal should be transported

For air transport, Container Note 78 of the IATA Live Animals Regulations should be followed.

Find this animal on ZooLex

Photo Copyright by
Ran Kirlian

Why do zoos keep this animal

Zoos keep fossa for a number of reasons. First and foremost fossa are facing a number of threats in their native Madagascar. Habitat destruction and alteration, hunting and trade have all meant that fossa numbers in the wild are declining. The small numbers of captive fossa act as an assurance population, providing a back-up in the eventuality of fossa becoming extinct in the wild. In addition captive fossa act as ambassadors for their wild cousins.

Fundraising for in situ conservation can be enhanced by enabling the public to see this unusual species and thereby engendering both interest and compassion. Zoos, whilst wishing to help conserve species in the wild, also hope to show their visitors some of the diversity of the planet. The fossa is a highly unusual species and rarely known outside of professional zoology circles. Finally, a population of fossa in zoos allows study of aspects of their behaviour and biology that would be almost impossible due to their solitary, secretive nature in the wild.

How this animal should be kept

The fossa is a challenging animal to keep in captivity due to its active dynamic nature, and the complexity of its social system. Males and females are often held as single animals in adjoining cages. However, while this means that they can be easily mixed it may also encourage high levels of repetitive pacing by one or both animals.

It is suggested that either compatible pairs are held in the same exhibit, as this can often work well, or that two enclosures, not in visual or strong olfactory contact, are utilised or constructed. If animals are held as a pair plans should be in place in the eventuality of any young being born. As there may be a risk of infanticide in this species it is not advised to hold young in the same exhibit as an adult male.

It's relatively straightforward to ascertain when fossa female are coming into mating condition. Scent-marking activity can noticeably increase, they can become more arboreal and they make a distinctive 'snore' vocalisation during this period. There is also some anecdotal evidence that the genitalia can become swollen and the reddish colouration around the groin area increases. Introductions between males and females can be made at this time.
Plentiful climbing apparatus should be supplied and fossa will exhibit dramatic climbing ability if encouraged to do so. They will use branches and relatively fine ropes, and will readily be observed using their long tails to balance. In the Northern hemisphere their ears are prone to frost damage and therefore heated indoor housing is essential. In winter this propensity to ear damage may mean locking them into dens overnight, therefore this indoor housing should be large and spacious.

As fossa are actively predacious a good variety of whole food items should be presented to them to encourage normal food processing behaviours. Items such chicken, rabbit, guinea pig and quail are suitable. Some fossa also like items such as eggs.

Fossa, males in particular, are extremely playful and items such as logs, plastic barrels, and cardboard boxes are used as play items. Rubbing different scents (spices, herbs etc.) on cage furniture can also promote play.