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By Barbara Lundrigan and Trevor Zachariah
Geographic Range
Fossas are found throughout forested areas of Madagascar. (Nowak, 1999)
Other Geographic Terms:
island endemic 
.
Habitat
(6560 ft)
Fossas inhabit all forested areas on the island of Madagascar. They range from the coastal lowlands to mountainous areas up to 2000 meters in elevation. (Nowak, 1999)
These animals are found in the following types of habitat:
tropical ; terrestrial .
Terrestrial Biomes:
savanna or grassland ; forest ; rainforest ; scrub forest .
Physical Description
(15.4 to 26.4 lbs)
(24.02 to 31.5 in)
Fossas are cat-like in appearance, with blunt noses and large, forward-facing eyes. Total body length ranges from 610 to 800 mm, with a tail of matching length. Shoulder height is typically 370 mm. Fossas have vibrissae that are as long as their heads, and are covered in short, thick fur of a reddish-brown color, although there are sometimes black individuals. They have short, curved, retractile claws and a plantigrade stance (Nowak 1999). Anal and preputial glands can be found. Males have a large baculum, a barb on the glans of the penis, and are slightly larger than females. They have rounded ears. Teeth are shorter and fewer in number (32 to 36) than other viverrids (Schliemann 1989). The generic name, Cryptoprocta, comes from the fact that the anus ("procta") is hidden ("crypto") by an anal pouch (Kohncke & Leonhardt 1986). (Kohncke and Leonhardt, 1986; Nowak, 1999; Schliemann, 1989)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: male larger.
Reproduction
Fossas breed once yearly.
Mating occurs in September and October.
Aggression among males may occur during the mating season, including threatening calls and postures, which lead to fights where each contestant tries to bite the other. Copulation can occur on the ground or on a horizontal branch. To signify her readiness to mate, the female lifts her hindquarters and turns her external genitalia inside out about two to three centimeters. The male then mounts her and bites the back of her neck. The period of copulation lasts up to 165 minutes (Schliemann 1989). (Schliemann, 1989)
Mating occurs in September and October, and young are born in a den in December and January after a three month gestation period. At birth the two to four young weigh 100 grams each. They are altricial, being toothless and blind, but furred (Kohncke & Leonhardt 1986). At four and a half months a young fossa is weaned and ventures out of the den (Nowak 1999). The young fossa leaves its mother when it reaches fifteen to twenty months of age, have adult teeth at 2 years old and attain full adult size at four years of age (Schliemann 1989, Nowak 1999). (Kohncke and Leonhardt, 1986; Nowak, 1999; Schliemann, 1989)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Young are cared for and nursed by females in the den until they are weaned. They are further protected until they become independent, at from 15 to 20 months old.
Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (protecting: female).
Lifespan/Longevity
While the life span of fossas has not been studied in the wild, one specimen lived twenty years in captivity (Kohncke & Leonhardt 1986). (Kohncke and Leonhardt, 1986)
Behavior
Fossas are secretive and primarily nocturnal or crepuscular, though they are occasionally observed during the day. They are solitary, except during the mating season. Fossas are territorial, both sexes mark their territory with scent glands. Aggressive behavior is not common, except during the mating season. (Nowak, 1999)
Home Range
Fossas are territorial, requiring approximately one square kilometer of territory. (Nowak, 1999)
Key behaviors:
scansorial; cursorial; terricolous; nocturnal ; crepuscular ; motile ; sedentary ; solitary ; territorial .
Communication and Perception
Fossas have keen vision, hearing, and smell. They mark their territories with secretions from their scent glands and may use chemical cues to communicate reproductive status. (Haltenorth and Diller, 1980)
Other communication keywords:
scent marks .
Food Habits
Fossas are the largest mammalian carnivores on the island of Madagascar. Their diet consists of small mammals, birds, reptiles, amphibians, and insects. Fossas also prey on lemurs (Lemuridae). They are excellent climbers and will pursue lemurs through the trees. (Nowak, 1999)
Primary Diet:
carnivore (eats terrestrial vertebrates).
Animal Foods:
birds; mammals; amphibians; reptiles; insects.
Predation
- humans (Homo sapiens)
Fossas are top predators on Madagascar. Their main predators are humans. Young fossas may fall prey to large snakes or birds of prey, although this is not documented. Fossas are cryptically colored and secretive. (Kohncke and Leonhardt, 1986)
Anti-predator adaptations::
cryptic .
Ecosystem Roles
Fossas are the top, mammalian predators on Madagascar. They impact the populations of many species of small mammals, birds, reptiles, and amphibians.
Economic Importance for Humans: Negative
Among humans, fossas have an exaggerated reputation for savagery and destruction. They do sometimes prey upon domestic poultry, and there have even been accounts of attacks on oxen and goats, but these are rare and their veracity may be questionable. (Nowak, 1999)
Economic Importance for Humans: Positive
Fossas are fascinating members of a unique Malagasy mammalian radiation. They are charismatic animals and are important in ecotourism.
Ways that people benefit from these animals:
ecotourism ; research and education.
Conservation Status
IUCN Red List: [link]:
Endangered.
US Federal List: [link]:
No special status.
CITES: [link]:
Appendix II.
Fossas are widely hunted, and their habitat is constantly being enroached upon by humans. Fossas were upgraded from "vulnerable" to "endangered" by the IUCN in 2000 based on estimates that only 2500 individuals survive in increasingly fragmented habitat. (Nowak, 1999)
Contributors
Barbara Lundrigan (author), Michigan State University. Trevor Zachariah (author), Michigan State University.
Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of Zoology.
