The fossa databse, probably one of the largest database about the fossa on the net. It provies as much information as possible on the fossa.
This page can grow and or get updates anytimes so check it out often.
Photos on here are fair use, NO commercial purposes,
so it means I make NO profit out of these photos. They are for educational purposes...
The fossa (Cryptoprocta ferox) (pronounced /ˈfɒsə/ or /ˈfuːsə/, Malagasy [ˈfusə̥]) is a cat-like, carnivorous mammal that is endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family (Herpestidae). Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a close relationship with viverrids (most civets and their relatives). Its classification, along with that of the other Malagasy carnivores, influenced hypotheses about how many times mammalian carnivores have colonized the island. With genetic studies demonstrating that the fossa and all other Malagasy carnivores are most closely related to each other (forming a clade, recognized as the family Eupleridae), carnivores are now thought to have colonized the island once around 18 to 20 million years ago.
The fossa is the largest mammalian carnivore on the island of Madagascar and has been compared to a small cougar. Adults have a head-body length of 70–80 cm (28–31 in) and weigh between 5.5–8.6 kg (12–19 lb), with the males larger than the females. It has semi-retractable claws and flexible ankles that allow it to climb up and down trees head-first, and also support jumping from tree-to-tree. The fossa is unique within its family for the shape of its genitalia, which share traits with those of cats and hyenas.
The species is widespread, although population densities are usually low. It is found solely in forested habitat, and actively hunts both day and night. Over 50% of its diet consists of lemurs, the endemic primates found on the island, though tenrecs, rodents, lizards, birds, and other animals are also documented as prey. Mating usually occurs in trees on horizontal limbs and can last for several hours. Litters range from one to six pups, which are born blind and toothless (altricial). Infants wean after 4.5 months and are independent after a year. Sexual maturity occurs around three to four years of age, and life expectancy in captivity is 20 years. The fossa is listed as "Vulnerable" by the International Union for Conservation of Nature (IUCN). It is generally feared by the Malagasy people and is often protected by their taboo, known as fady. The greatest threat to the species is habitat destruction.
Wild fossa walking.
The sounds are in wave format .wav .
Angry fossa 1 (sound) Angry fossa 2 (sound) Angry fossa 3 (sound)
Fossa mating calls 1 (sound) Fossa mating calls 2 (sound)
Fossa communication (sound)
Fossa growl (sound)
Fossa scream 1 (sound)
Fossa scream 2 (sound)
Fossa makes a quiet sound (sound)
Fossa making a bark-like sound (sound)
Fossa sniffing (sound)
Fossa screaming 1 (sound)
Fossa screaming 2 (sound)
Fossa screaming 3 with Luke Dollar saying the fossa (sound)
TaxomonyThe fossa was formally described in 1833 by Edward Turner Bennett. The genus name Cryptoprocta refers to how the animal's anus is hidden by its anal pouch, from the Ancient Greek words crypto- "hidden", and procta "anus". The species name ferox is the Latin adjective "fierce" or "wild." Its common name is Malagasy and can be spelled fossa or fosa. The common name is the same as the generic name of the Malagasy civet (Fossa fossana), but they are different species. Because of shared physical traits with civets, mongooses, and cats (Felidae), its classification has been controversial. Bennett originally placed the fossa as a type of civet in the family Viverridae, a classification that long remained popular among taxonomists. Its compact braincase, large eye sockets, retractable claws, and specialized carnivorous dentition have also led some taxonomists to associate it with the felids. In 1939, William King Gregory and Milo Hellman placed the fossa in its own subfamily within Felidae, the Cryptoproctinae. George Gaylord Simpson placed it back in Viverridae in 1945, still within its own subfamily, yet conceded it had many cat-like characteristics.
In 1993, Géraldine Veron and François Catzeflis published a DNA hybridization study suggesting that the fossa was more closely related to mongooses (family Herpestidae) than to cats or civets. However, in 1995, Veron's morphological study once again grouped it with Felidae. In 2003, molecular phylogenetic studies using nuclear and mitochondrial genes by Anne Yoder and colleagues showed that all native Malagasy carnivorans share a common ancestry that excludes other carnivores (meaning they form a clade, making them monophyletic) and are most closely related to Asian and African Herpestidae. To reflect these relationships, all Malagasy carnivorans are now placed in a single family, Eupleridae. Within Eupleridae, the fossa is placed in the subfamily Euplerinae with the falanouc (Eupleres goudoti) and Malagasy Civet, but its exact relationships are poorly resolved.
An extinct relative of the fossa was described in 1902 from subfossil remains and recognized as a separate species, Cryptoprocta spelea, in 1935. This species was much larger than the living fossa, but otherwise similar. Across Madagascar, people distinguish two kinds of fossa—a large fosa mainty ("black fossa") and the smaller fosa mena ("reddish fossa")—and a white form has been reported in the southwest. It is unclear whether this is purely folklore or individual variation—related to sex, age or instances of melanism and leucism—or whether there is indeed more than one species of living fossa. The fossa has a cat-like appearance, resembling a small cougar.
Also the jaguarundi from South America looks a lot like the fossa.
The fossa appears as a diminutive form of a large felid, such as a cougar, but with 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, its eyes reflect light; the reflected light is orange in hue. Its head-body length is 70–80 cm (28–31 in) and its tail is 65–70 cm (26–28 in) long. There is some sexual dimorphism, with adult males (weighing 6.2–8.6 kg; 14–19 lb) being larger than females (5.5–6.8 kg; 12–15 lb). Smaller individuals are typically found north and east on Madagascar, while larger ones to the south and west. Unusually large individuals weighing up to 20 kg (44 lb) have been reported, but there is some doubt as to the reliability of the measurements. The fossa can smell, hear, and see well. It is a robust animal and illnesses are rare in captive fossas. Cranium (dorsal, ventral, and lateral views) and mandible (lateral and dorsal views)
Fig. 3. Dorsal, ventral , and leteral views of the cranium, and lateral and dorsal views of the mandible of an adult Cryptoprocta ferox
(total length of the skull is 140mm; from Milne-Edwards and Grandidier, 1867).
Both males and females have short, straight fur that is relatively dense and without spots or patterns. Both sexes are generally a reddish-brown dorsally and colored a dirty cream ventrally. When in rut, they may have an orange coloration to their abdomen from a reddish substance secreted by a chest gland secretions when in rut, but this has not been consistently observed by all researchers. The tail tends to be lighter in coloration than the sides. Juveniles are either gray or nearly white.
Several of the animal's physical features are adaptions to climbing through trees. It uses its tail to aid in balance and has semi-retractable claws that it uses to climb trees in its search for prey. It has semiplantigrade feet, switching between a plantigrade-like gait (when arboreal) and a digitigrade-like one (when terrestrial). The soles of its paws are nearly bare and covered with strong pads. The fossa has very flexible ankles that allow it to readily grasp tree trunks so as to climb up or down trees head first or to leap to another tree. Captive juveniles have been known to swing upside down by their hindfeet from knotted ropes.
The fossa has several scent glands, although the glands are less developed in females. Like herpestids it has a perianal skin gland inside an anal sac which surrounds the anus like a pocket. The pocket opens to the exterior with a horizontal slit below the tail. Other glands are located near the penis or vagina, with the penile glands emitting a strong odor. Like the herpestids, it has no prescrotal glands. According to some recent pictures from conservationist a fossa actually may have a prescrotal glands [37b].
One of the more interesting physical features of this species is its external genitalia. Males have an unusually long penis and baculum (penis bone), reaching to between its forelegs when erect. The glans extends about halfway down the shaft and is spiny except at the tip. In comparison, the glans of felids is short and spiny, while that of viverrids is smooth and long. The female fossa exhibits transient masculization, starting at about 1–2 years of age, developing an enlarged, spiny clitoris that resembles a male's penis. The enlarged clitoris is supported by an os clitoridis, which decreases in size as the animal grows. Females do not have a pseudo-scrotum, but they do secrete an orange substance that colors their underparts, much like the secretions of males. Hormone levels (testosterone, androstenedione, dihydrotestosterone) do not seem to play a part in this transient masculization, as those levels are the same in masculinized juveniles and nonmasculinized adults. It is speculated that the transient masculization either reduces sexual harassment of juvenile females by adult males, or reduces aggression from territorial females. While females of other mammal species (such as the spotted hyena) have a pseudo-penis, none of them are known to have theirs diminish in size as the animal grows.
Picture of what their fur look like. (No animals were harmed, is a picture rip from a well posed animal at the zoo.)
Comparison with related carnivores Overall, the fossa has features in common with three different carnivoran families, leading researchers to place it and other members of the Eupleridae alternatively in Herpestidae, Viverridae, and Felidae. Felid features are primarily those associated with eating and digestion, including teeth shape and facial portions of the skull, the tongue, and the digestive tract, typical of its exclusively carnivorous diet. The remainder of the skull most closely resembles those of genus Viverra, while the general body structure is most similar to that of various members of Herpestidae. The permanent dentition is (three incisors, one canine, three or four premolars, and one molar on each side of both the upper and lower jaws), with the deciduous formula being similar but lacking the fourth premolar and the molar. The fossa has a large, prominent rhinarium similar to that of viverrids, but has comparatively larger, round ears, almost as large as those of a similarly sized felid. Its facial vibrissae (whiskers) are long, with the longest being longer than its head. Like some mongoose genera, particularly Galidia (which is now in the fossa's own Eupleridae family) and Herpestes (of Herpestidae), it has carpal vibrassae as well. Its claws are retractile, but unlike those of Felidae species, they are not hidden in skin sheaths. It has three pairs of nipples (one inguinal, one ventral, and one pectoral).
Anatomy Body anatomy
Fossa's full view.
Fossa fore paws.
Fossa's paws. They use for climbing, attacking and grabbing. They can't grab stuff like primates.
Fossa holding some toy at the zoo,
Fossa grab things just like felines and other animals.
The forepaw of the fossa (frontal paw).
has semi-retractable claws.
Fossa claws completely out.
Fossa hind legs.
The fossa's hind legs.
Fossa forefoot pad.
Fossa's forepaw undernearth showing its foot pad.
Conservationist holding to show the fossas's hind feet pad.
The fossa's hind feet.
The fossa has an extremely long tail to help with balance.
The fossa's long tail provides balance for pursing this agile prey through the trees.
Fossas tail are 70 to 90 cm long while the male head-body length: 75 – 80 cm and female head-body length: 65 - 70 cm.
Fossa head frontal view.
Fossa head side view.
Fossas have pretty long whiskers.
Its whiskers can be as long as its head.
Fossa mouth and nose.
The fossa teeth (this one isn't dead, is yawning at the zoo or wild).
Fossa have very sharp teeth. Teeth are shorter and fewer in number
(32 to 36) than other viverrids.
Fossa have pretty sharp teeth.
Fossa tongue and teeth.
The fossa tongue
has backwards-facing spines
just like the cat.
Spines are called papillae. These are quite rigid, as they contain keratin.
Fossa tongue a little bit out.
The underneath of a fossa tongue.
The fossa has a nose like most viverrids.
Fossas have a large bulbous nose and they have a very good sense of smell.
The fossa eye has a vertical slit just like felines and some other animals.
Fossas have keen vision, very good eyesight.
Eye side view.
ears aren't pointy they are rounded.
Fossas have acute hearing.
Ears side view.
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.  MALES
Male fossa penis sheath.
Male fossa genitalia.
Male fossa full genital area including testes and anal pouch.
(Click to enlarge)
Males have an unusually long penis and baculum , reaching to between its forelegs when erect.  The glans extends down the shaft about halfway and is spiny except at the tip.  In comparison, the glans of felids is short and spiny, while that of viverrids is smooth and long. 
Fossa penis sideview 
Fossa's penis has backward facing barbs
also called penile spines.
Picture on the left is the penis showing its spines.
Picture on the right is the penile spines in very close view in high resolution.
In species which retain the full expression of penile spines, penile spines contribute to sexual pleasure and quicker orgasms. 
Non-masculinized "regular clitoris" of the female fossa.
Masculinised clitoris with spikes (barbs) of the female fossa. Masculinised clitoris with ossicle of the female fossa. Female fossa clitoris  Fossa anal area.
The fossa's anus is barely visible because it has a pouche hiding it.
Different picture of the fossa's anal area.
The fossa has an anal pouche.  Skull, skeleton and misc anatomy Fossa skull underneath.
Ventral views of the cranium of the recently collected Cryptoprocta ferox Bennett, 1833 (above) and the neotype subfossil C. spelea Grandidier, 1902 (MNHN 1977.755). The specimen of C. ferox (AMNH 188213) collected at Manakara in 1931 is amongst some of the larger modern individuals of this species measured during the course of this study. Scale bar: 10 cm.  Fossa skull side.
Lateral views of the cranium of a recently collected Cryptoprocta ferox Benett, 1833 (above) and the neotype subfossil C. spelea Grandidier, 1902 (MNHN 1977.755). The specimen of C. ferox (AMNH 188213) collected at Manakara in 1931 is amongst some of the larger modern individuals of this species measured during the course of this study. Scale bar: 10 cm. 
Fossa skull (This is a replica but matches the real one).
Skeleton anatomy. Internal anatomy Computed tomography of the fossa penis with the os penis (baculum).
Males have a large baculum.
The anatomy of the reproductive organs of the male fossa.
1, Os penis (baculum)
2, Prostate gland
The anatomy of the reproductive organs of the female fossa.
6, Corpus uteri
7, Uterine horns
Ovaries The prescrotal gland of the male fossa.
The pre-scrotal gland was a single gland identified in 8 of the 14 males. It seemed to be situated within the skin direcly cranial or between the testes. The gland was assumed to play its part in the orange staining of the male fossa during the breeding season.
Os clitoris of the female fossa.
The three juvenile females showed the expected signs of masculinization. The assumed regression of the os clitoris could not be proven. An os clitoris was detected in only 5 of the 10 adults.
Habitat and distribution
The fossa has the most widespread geographical range of the Malagasy carnivores, and is generally found in low numbers throughout the island in remaining tracts of forest, preferring pristine undisturbed forest habitat. It is also encountered in some degraded forests, but in lower numbers. Although the fossa is found in all known forest habitats throughout Madagascar, including the western, dry deciduous forests, the eastern rainforests, and the southern spiny forests, it is seen more frequently in humid than in dry forests. This may be because the reduced canopy in dry forests provides less shade, and also because the fossa seems to travel more easily in humid forests. It is absent from areas with the heaviest habitat disturbance and, like most of Madagascar's fauna, from the central high plateau of the country.
The fossa has been found across several different elevational gradients in undisturbed portions of protected areas throughout Madagascar. In the Réserve Naturelle Intégrale d'Andringitra, evidence of the fossa has been reported at four different sites ranging from 810 to 1,625 m (2,660 to 5,331 ft). Its highest known occurrence was reported at 2,000 m (6,600 ft); its presence high on the Andringitra Massif was subsequently confirmed in 1996. Similarly, evidence has been reported of the fossa at the elevational extremes of 440 m (1,440 ft) and 1,875 m (6,152 ft) in the Andohahela National Park. The presence of the fossa at these locations indicates its ability to adapt to various elevations, consistent with its reported distribution in all Madagascar forest types. (Up left) deciduous forest, (Up right) spiny forest and (Down left) rainforest.
BehaviorThe fossa 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 animal generally does not reuse sleeping sites, but females with young do return to the same den. The home ranges of male fossas in Kirindy Forest are up to 26 km2 (10 sq mi) large, compared to 13 km2 (5.0 sq mi) for females. These ranges overlap—by about 30% according to data from the eastern forests—but females usually have separated ranges. Home ranges grow during the dry season, perhaps because less food and water is available. In general, radio-collared fossas travel between 2 and 5 kilometres (1.2 and 3.1 mi) per day, although in one reported case a fossa was observed moving a straight-line distance of 7 km (4.3 mi) in 16 hours. The animal's population density appears to be low: in Kirindy Forest, where it is thought to be common, its density has been estimated at one animal per 4 km2 (1.5 sq mi) in 1998. Another study in the same forest between 1994 and 1996 using the mark and recapture method indicated a population density of one animal per 3.8 km2 (1.5 sq mi) and one adult per 5.6 km2 (2.2 sq mi).
Except for mothers with young and occasional observations of pairs of males, animals are usually found alone, so that the species is considered solitary. A 2009 publication, however, reported a detailed observation of cooperative hunting, wherein three male fossas hunted a 3 kg (6.6 lb) sifaka (Propithecus verreauxi) for 45 minutes, and subsequently shared the prey. This behavior may be a vestige of cooperative hunting that would have been required to take down larger recently extinct lemurs.
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. Females mew during mating and males produce a sigh when they have found a female. Throughout the year, animals produce long-lasting scent marks on rocks, trees, and the ground using glands in the anal region and on the chest. They also communicate using face and body expression, but the significance of these signals is uncertain. The animal is aggressive only during mating, and males in particular fight boldly. After a short fight, the loser flees and is followed by the winner for a short distance. In captivity, fossas are usually not aggressive and sometimes even allow themselves to be stroked by a zookeeper, but adult males in particular may try to bite. Fossa are active both day and night (cathemeral).
Fossa claw mark on a baobab tree.
DietThe fossa is a carnivore that hunts small to medium-sized animals. One of eight carnivorous species endemic to Madagascar, the fossa is the island's largest surviving endemic terrestrial mammal and the only predator capable of preying upon adults of all extant lemur species, the largest of which can weigh as much as 90% of the weight of the average fossa. Although it is the predominant predator of lemurs, reports of its dietary habits demonstrate a wide variety of prey selectivity and specialization depending on habitat and season; diet does not vary by sex. While the fossa is thought to be a lemur specialist in Ranomafana National Park, its diet is more variable in other rain forest habitats.
The diet of the fossa in the wild has been studied by analyzing their distinctive scats, which resemble gray cylinders with twisted ends and measure 10–14 cm (3.9–5.5 in) long by 1.5–2.5 cm (0.6–1.0 in) thick. Scat collected and analyzed from both Andohahela and Andringitra contained lemur matter and rodents. Eastern populations in Andringitra incorporate the widest recorded variety of prey, including both vertebrates and invertebrates. Vertebrates consumed ranged from reptiles to a wide variety of birds, including both understory and ground birds, and mammals, including insectivores, rodents, and lemurs. Invertebrates eaten by the fossa in the high mountain zone of Andringitra include insects and crabs. One study found that vertebrates comprised 94% of the diet of fossas, with lemurs comprising over 50%, followed by tenrecs (9%), lizards (9%), and birds (2%). Seeds, which comprised 5% of the diet, may have been in the stomachs of the lemurs eaten, or may have been consumed with fruit taken for water, as seeds were more common in the stomach in the dry season. The average prey size varies geographically; it is only 40 grams (1.4 oz) in the high mountains of Andringitra, in contrast to 480 grams (17 oz) in humid forests and over 1,000 grams (35 oz) in dry deciduous forests. In a study of fossa diet in the dry deciduous forest of western Madagascar, more than 90% of prey items were vertebrates, and more than 50% were lemurs. The primary diet consisted of approximately six lemur species and two or three spiny tenrec species, along with snakes and small mammals. Generally, the fossa preys upon larger lemurs and rodents in preference to smaller ones.
Prey is obtained by hunting either on the ground or in the trees. During the non-breeding season the fossa hunts individually, but during the breeding season hunting parties may be seen, and these may be pairs or later on mothers and young. One member of the group scales a tree and chases the lemurs from tree to tree, forcing them down to the ground where the other is easily able to capture them. The fossa is known to eviscerate its larger lemur prey, a trait that, along with its distinct scat, helps identify its kills. Long-term observations of the fossa's predation patterns on rainforest sifakas suggest that the fossa hunts in a subsection of their range until prey density is increased, then moves on. The fossa has been reported to prey on domestic animals, such as goats and small calves, and especially chickens. In captivity, the fossa consumes between 800 and 1,000 grams (28 and 35 oz) of meat a day. Food taken in captivity includes amphibians, birds, insects, reptiles, and small- to medium-sized mammals. This wide variety of prey items taken in various rainforest habitats is similar to the varied dietary composition noted occurring in the dry forests of western Madagascar, as well. As the largest endemic predator on Madagascar, this dietary flexibility combined with a flexible activity pattern has allowed it to exploit a wide variety of niches available throughout the island, making it a potential keystone species for the Madagascar ecosystems. Fossa eating meat. In two different position.
But captive fossas will mostly eat rats, mice, quail
and chicken. Reproduction
Fossa illustration circa 1927
Most of the details of reproduction in wild populations are from the western dry deciduous forests; whether certain of these details are applicable to eastern populations will require further field research. Mating typically occurs during September and October, although there are reports of it occurring as late as December, and can be highly conspicuous. In captivity in the Northern Hemisphere, fossas instead mate in the northern Spring, from March to July. Intromission usually occurs in trees on horizontal limbs about 20 m (66 ft) off the ground. Frequently the same tree is used year after year, with remarkable precision as to the date the season commences. Trees are often near a water source, and have limbs strong enough and wide enough to support the mating pair, about 20 cm (7.9 in) wide. Some mating has been reported on the ground as well.
As many as eight males will be at a mating site, staying in close vicinity to the receptive female. The female seems to choose the male she mates with, and the males compete for the attention of the female with a significant amount of vocalization and antagonistic interactions. The female may choose to mate with several of the males, and her choice of mate does not seem to have any correlation to the physical appearance of the males.
To stimulate the male to mount her, she gives a series of mewling vocalizations. The male mounts from behind, resting his body on her slightly off-center, a position requiring delicate balance; if the female were to stand, the male would have significant difficulty continuing. He places his paws on her shoulders or grasps her around the waist and often licks her neck. Mating may last for nearly three hours. This unusually lengthy mating is due to the physical nature of the male's erect penis, which has backwards-pointing spines along most of its length. Fossa mating includes a copulatory tie,  which may be enforced by the male's spiny penis. The tie is difficult to break if the mating session is interrupted. Copulation with a single male may be repeated several times, with a total mating time of up to fourteen hours, while the male may remain with the female for up to an hour after the mating. A single female may occupy the tree for up to a week, mating with multiple males over that time. Also, other females may take her place, mating with some of the same males as well as others. This mating strategy, whereby the females monopolize a site and maximize the available number of mates, seems to be unique among carnivores. Recent research suggests that this system helps the fossa overcome factors which would normally impede mate-finding, such as low population density and lack of den use.
The birthing of the litter of one to six (typically two to four) takes place in a concealed location, such as an underground den, a termite mound, a rock crevice, or in the hollow of a large tree (particularly those of the Commiphora genus). Contrary to older research, litters are of mixed sexes. Young are born in December or January, making the gestation period 90 days, with the late mating reports indicating a gestational period of about six to seven weeks. The newborns are blind and toothless, and weigh no more than 100 g (3.5 oz). The fur is thin and has been described as gray-brown or nearly white. After about two weeks the cubs' eyes open, they become more active, and their fur darkens to a pearl gray. The cubs do not take solid food until three months old, and do not leave the den until they are 4.5 months old; they are weaned shortly after that. After the first year, the juveniles are independent of their mother. Permanent teeth appear at 18 to 20 months. Physical maturity is reached by about two years old, but sexual maturity does not happen for another year or two, and the young may stay with their mother until they are fully mature. Lifespan in captivity is up to or past 20 years of age, possibly due to the slow juvenile development.
Longevity in the wild is possibly into teens.
Mother with 2 cubs.
Very young cub.
Unusual mating Fossas have a very unusual mating system. A single female will exclusively occupy a site high in a tree, below which a number of males congregate. The males compete for mating rights, and over the course of a week, the female will mate with a number of different males. Once the original female has left, a new female will take over the site and, like her predecessor, mates with the males there. These ‘mating trees’ are used for many years. Mating occurs in September and October, with females giving birth to between 2 and 4 young approximately three months later. The young are blind and helpless at birth, each weighing around 100 g. Weaning occurs at around 4-5 months, but the young remain with their mother until they are 15-20 months old. Observations in captivity indicate that sexual maturity is not attained until 4 years. The lifespan of this species in the wild is not known, although it has been known to live for more than 20 years in captivity. The fossa is a top predator and therefore plays a very important role in its ecosystem through controlling the population size of its prey species. Fossas during a copulatory lock Males have very long penises, which are equipped with spines. These spines might allow them to maintain the copulatory lock ,which is another characteristic of fossa copulations.Video below
Transient masculinization in the fossa Transient Masculinization in the Fossa, Cryptoprocta ferox (Carnivora, Viverridae) Abstract
Department of Zoology, 3 University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom
National Environment Research Council Molecular Genetics in Ecology Initiative, 4 Department of Zoology, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom
Department of Obstetrics and Gynaecology, 5 University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom
Ecology and Epidemiology Group, 6 Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
In at least 9 mammalian species, females are masculinized throughout life, but the benefits of this remain unclear despite decades of thorough study, in particular of the spotted hyaena (Crocuta crocuta) in which the phenomenon has been associated with a high fitness cost. Through examination of wild and captive fossas (Cryptoprocta ferox, Viverridae), androgen assays, and DNA typing for confirmation of gender, we made the first discovery of transient masculinization of a female mammal. Juvenile female fossas exhibited an enlarged, spinescent clitoris supported by an os clitoridis and a pigmented secretion on the underpart fur that in adults was confined to males. These features appeared to diminish with age. The majority of adult females lacked them, and os clitoridis length was inversely related to head-body length. No evidence was found to link this masculinization to elevated female androgen levels. Circulating concentrations of testosterone and androstenedione, but not dihydrotestosterone, were significantly lower in females than in males. No significant differences in testosterone, androstenedione, or dihydrotestosterone levels were found between juvenile (masculinized) and adult (nonmasculinized) females. There are several possible physiological mechanisms for this masculinization. None of the hypotheses so far proposed to explain the evolutionary basis of female masculinization in mammals are applicable to our findings. We present 2 new hypotheses for testing and development.
Females of several mammal species are masculinized throughout life, including moles (Talpa) [1a, 2a], spotted hyaenas (Crocuta crocuta) [3a], and a number of less thoroughly investigated primate genera (e.g., Ateles, Allouatta, Cebus, and Lagothrix) [4a, 5a]. In the most well-studied species, the spotted hyaena, such masculinization leads to difficulties the first time a female gives birth, estimated as a lifetime fitness cost of 16–25% [6a]. A substantial, obvious benefit that would outweigh such a cost is to be expected, yet for no mammal species has the adaptive value of female masculinization been clearly established.
Two groups of explanations for female masculinization in mammals have been proposed (reviewed in [7a, 8a]). The first group applies to species where increased aggression confers higher female fitness. Female masculinization has been interpreted as a nonadaptive consequence of raised androgen levels, which are thought to be selected for because they raise aggression levels. Studies of androgen levels in 2 species exhibiting female masculinization support this view. In the spotted hyaena, female levels of circulating androstenedione are at least equal to [8a, 9a] if not higher than [10a, 11a] male levels (reviewed in [8a]). In the European mole, Talpa europaea, levels of circulating testosterone in females approach those in males outside the breeding season, being exceptionally high relative to those in other nonpregnant female mammals [12a]. Aggression is thought to benefit the spotted hyaena female either as a neonate in promoting siblicide [13a] or as an adult in mediating high social rank [7a]. It has been suggested that the female mole (Talpa europaea) benefits from aggression during territorial disputes [14a]. The alternative group of explanations for mammalian female masculinization includes proposals that masculinization itself could directly benefit female fitness. Wickler [15a] and Kruuk [16a] considered the masculinized genitalia of the female spotted hyaena as essential to the greeting ceremony that maintains individuals in a social group. East et al. [13a] proposed that the form of the genitalia gives an adult female hyaena control over mating, leading to beneficial male submission within the group.
Masculinization in 2 female museum specimens of the fossa (Cryptoprocta ferox) was described early in the last century [17a, 18a]. The fossa is a large, solitary civet endemic to Madagascar, with a head-body length of approximately 70 cm [19a]. To confirm these reports, we examined genital morphology in individuals of both sexes and a range of ages from a wild population and a captive group. To investigate the physiological basis and to identify possible adaptive benefits of any observed masculinization, we also measured androgen levels of individuals in the wild population.
MATERIALS AND METHODS
Capture, Examination, and Age Determination
Forty-three fossas were captured with box traps in Kirindy Forest, a dry deciduous forest in western Madagascar (20°4′S, 44°39′E) during 1994–1996. Trapping was concentrated in the dry season (May–October) after wet season trapping was found to generate a very low capture rate. Trapped animals were anesthetized with 5 mg ketamine and 1 mg xylazine per kilogram of body weight. Head-body length was measured. The os penis in males and the os clitoridis in females were located by palpation (the os clitoridis could also usually be clearly seen through the skin) and measured using callipers. Length of a testis was measured with callipers at the longest point. The quantity of orange secretion apparent on the underpart fur was scored by eye in terms of extent and depth of color (0–5): 0 = no orange perceptible anywhere on the underpart fur; 1 = orange just perceptible in at least 1 area of the underpart fur; 3 = clearly orange in certain areas of the underpart fur; 5 = all underpart fur an intense orange. Individuals with orange secretion midway between 1 and 3 were scored as 2, and those midway between 3 and 5 were scored as 4. Age was assessed by scoring tooth wear (0–5): 0 = no toothwear perceptible; 1 = 1 small indication of toothwear, e.g., 1 tip missing; 3 = clear signs of light wear, e.g., many tips missing; 5 = heavy wear on all teeth, discoloration. Scores of 2 and 4 for tooth wear were intermediate to 1 and 3, and 3 and 5, respectively. Adult females were examined for mammary development as an indicator of late pregnancy or lactation. This examination was done simply to confirm captive data and limited observations in the wild indicating that the reproductive season is exclusive to the wet season; pregnancy was not expected because most trapping was carried out during the dry season. Juveniles were distinguished by their small head-body length, unsuckled mammae, low level of tooth wear, and in those less than 20 mo of age, the presence of milk teeth. Because the fossa is a seasonal breeder, it was possible to age juveniles precisely (to the month) through presence/absence of milk teeth and head-body length [20a]. In captive animals, maturity is reached at 3–4 yr of age [20a, 21a].
Because all wild-caught juvenile females were over 10 mo old, 3 captive-born female fossas held at Suffolk Wildlife Park, U.K., were monitored bimonthly from the age of 10 wk in September 1997 until the age of 10 mo. The 3 females were from the same natal group and were kept together with their single brother throughout the monitoring period. Anesthesia was not permitted, precluding accurate measurements, but the underpart secretion was scored, the clitoris was examined, and when feasible, attempts were made to estimate os clitoridis length with a combination of palpation and callipers. The underpart secretion and genitalia of the young male were similarly monitored.
Confirmation of Sex by DNA Typing
Ear disks were collected during ear tagging of wild-caught fossas. Total cellular DNA was extracted [22a] from ear disks and used to detemine the sex of each animal by polymerase chain reaction (PCR) detection of the male-specific SRY gene as described previously [23a]. PCR detection of 5 microsatellites [24a] provided a positive control for PCR function in females.
Between June 1995 and September 1996, blood samples were collected from fossas at the place of capture into heparinized vacutainers and centrifuged for 10 min. The volumes of the resulting plasma samples were recorded prior to storage in cold water until arrival at base camp (<16 h), where steroids were extracted into methanol by passage through Sep-Pak Plus C18 cartridges (Millipore U.K. Ltd., Watford, U.K.) and refrigerated. This step was carried out to protect the steroids from damage by hostile conditions and bacterial breakdown in the field.
In Aberdeen, in June 1997, all samples were dried in air at 37°C prior to reconstitution in 2 ml of DELFIA assay buffer (PerkinElmer Life Sciences, Cambridge, U.K.), a Tris-HCl buffered NaCl solution, pH 7.8, containing <10% BSA, bovine γ globulins, Tween 40, diethylenetriaminepentaacetic acid, and an inert red dye. The recovery of testosterone from adult male human blood following the Sep-Pak extraction was 92%. Androstenedione was measured using a single Coat-a-Count extraction androstenedione kit (EURO/DPC Ltd., Caernarfon, U.K.). Because the blood samples had already been extracted into methanol, the ethyl ether extraction step was omitted. Testosterone was measured using a single DELFIA kit (PerkinElmer Life Sciences), substituting DELFIA assay buffer for kit buffer and the testosterone reference preparation T1268 (Sigma-Aldrich Co. Ltd., Poole, U.K.), made up in methanol, dried, and reconstituted in DELFIA assay buffer. Dihydrotestosterone was measured using a single dihydrotestosterone kit (DSL U.K. Ltd, Tooting, U.K.), with 400-μl aliquots of each reconstituted fossa sample used for oxidation and hexane/ethanol extraction steps carried out according to kit instructions.
The recovery of added steroids from fossa plasma was linear and proportional, and the serial dilution of fossa plasma was parallel to each standard curve (Fig. 1). The recovery of standard added with sample was 97.0% for testosterone, 96.9% for androstenedione, and 97.4% for dihydrotestosterone. For each hormone, all samples were determined in a single assay. The preliminary assay of randomly selected samples enabled the dilution of the samples where appropriate so that all androgen values determined for the fossa samples fell within the ranges of the standard curves. Because the androgen concentrations were measured in single assays, typical assay performance figures are given. Specifically, the sensitivities and intra-assay coefficients of variation were 0.4 nmol/L and 4–8% for testosterone, 0.07 nmol/L and 5–8% for androstenedione, and 14 pmol/L and 3–6% for dihydrotestosterone, repectively. Cross-reactivities for the assay kits are 0.2% and 12.0% for testosterone with androstenedione and dihydrotestosterone, respectively; 1.9% and 0.02% for dihydrotestosterone with androstenedione and testosterone, respectively; 0.2% and 0.2% for androstenedione with testosterone and dihydrotestosterone, respectively. From 22 individuals, more than 1 sample was obtained on different occasions. For each of these, the median value was used in the analyses. Data Analysis
Secretion scores were expressed as medians with ≥95% nonparametric confidence intervals (CIs) obtained using the binomial distribution [25a]. The same method was used to compare androgen levels graphically, but using ≥80% CIs because of the smaller sample sizes. Scores and androgen levels were compared between males and females and between adults and juveniles using the Mann-Whitney U-test. Os clitoridis lengths of adult and juvenile females were compared using an unpaired two-tailed t-test. Various correlations between androgen levels, morphological measurements, and scores were tested using the Spearman rank correlation procedure. RESULTS
We examined 43 wild-caught fossas: 18 adult males, 7 juvenile males, 10 adult females, and 8 juvenile females. As expected, none of the adult females was perceptibly pregnant or lactating; only 1 of them was caught during the reproductive season. Juvenile males ranged in age from 8 mo to 31 mo, and juvenile females ranged from 12 mo to 33 mo; 1 female 40 mo of age was also classed as a juvenile because of her nonparous state and a tooth wear score of 0. We also examined a litter of 4 captive-born juveniles: 1 male and 3 females.
Wild-caught individuals were sexed without difficulty in the field, and the sex of these individuals was confirmed by DNA typing for the male-specific SRY gene. Each adult male fossa (Fig. 2a) had prominent testes and a large penis. The latter was supported by a bone, and the drawing back of the sheath revealed a profuse covering of hard spines along the basal two thirds of its length. A mildly pungent orange (Mars Orange [26a]) secretion stained the cream-colored fur between the throat and anus of the adult males, especially between the forelimbs and the hind limbs. All 7 wild-caught and the single captive-born juvenile male fossas resembled the adult males in all these features, including secretion score (Table 1), except that their genitalia were not as large relative to body size; the ratio of testis length:head-body length differed significantly between adults and juveniles (Mann-Whitney U′ = 108, P < 0.001), as did the ratio of os penis length:head-body length (U′ = 53, P < 0.001). The 10 wild-caught adult females (Fig. 2b) lacked all but 1 of these features: 4 of these females possessed a small bone (os clitoridis) within the tip of the clitoris, which was hard and inflexible when palpated. All adult females had cream-colored (Ivory Yellow [26a]) underparts, with little or no perceptible orange secretion. Click to enlarge
In contrast with the adult females, all 8 wild-caught juvenile females (Fig. 2c), although easily distinguishable from males, possessed several masculine features. The clitoris was substantially enlarged relative to that of the adult female and was supported in all individuals by an os clitoridis that was significantly larger than that found in the 4 adult females (Table 1; t8 = 5.703, P < 0.001). The anterior of the clitoris base was covered with spines (or in 1 animal a hard crust) in 6 individuals. A raised, naked region, reminiscent of a penis raphe, lay between the anus and the genital opening, and the secretion score was significantly higher than that in adult females (Table 1; Mann-Whitney U′ = 7 1.5, P < 0.01).
Very young female fossas showed little masculinization. At the first examination, at the age of 10 wk, the only masculine feature apparent in the captive-born females was an os clitoridis. This bone was present in only 2 of the 3 individuals and, at an estimated 2–4 mm long, was clearly smaller than that found in the older wild-caught juveniles. By the age of 7 mo, each female had an enlarged clitoris, an os clitoridis of estimated length 10–15 mm, and tiny (~1 mm long) spines at the clitoris base but still exhibited little or no underpart secretion by the age of 10 mo, when examination ended.
These masculine features appeared to be transient in females and were most pronounced in the second and third years of life. None of the features, apart from the os clitoridis in a reduced form, was found in any adult female, and the features were also reduced in females <1 yr old. Head-body length of females with an os clitoridis was negatively correlated with both os clitoridis length (Spearman rank correlation: rs = −0.839, P < 0.02, n = 10) and secretion score (rs = −0.882, P < 0.01, n = 11) (Fig. 3). Three of the 4 adult females possessing an os clitoridis had the lowest tooth wear scores for adults, indicating that they were relatively young.
We found no evidence that masculinization of female fossas is androgen dependent. Blood samples taken from 13 adult male, 10 adult female, 4 juvenile male, and 6 juvenile female wild-caught fossas were assayed for 3 androgens: androstenedione, testosterone, and dihydrotestosterone (Fig. 4). In both juveniles and adults, median androstenedione and testosterone levels were higher in males than in females (Mann-Whitney U-test, androstenedione: juveniles U′ = 24, P < 0.05, adults U′ = 130, P < 0.0001; testosterone: juveniles U′ = 22, P < 0.05, adults U′ = 103, P < 0.02), although the difference was not significant for dihydrotestosterone levels in either age class. No significant differences were found between juvenile and adult levels of any androgen in either females or males (Mann-Whitney U-test, P > 0.05). No significant relationship was found between levels of any androgen and os clitoridis length (Spearman rank correlation, P > 0.05, n = 9) or secretion score within females (Spearman rank correlation, P > 0.05, n =16).
Uniquely among all mammals so far examined, masculinization in the female fossa appears to be a transient feature, most pronounced in juveniles 1–2 yr of age. In captivity, the mother is aggressive towards her young once they reach the age of 12 mo (A. Winkler, personal communication). This observation and the fact that all but 1 wild-caught juvenile were at least 12 mo old suggest that 12 mo is the age at which juveniles become independent of the mother and disperse, the females retaining their masculine features until they reach sexual maturity at 3–4 yr.
The form of masculinization we observed corresponds in all aspects to the descriptions by Lönnberg [17a] and Carlsson [18a] of their respective single specimens with 3 exceptions. Lönnberg described a pseudoscrotum, but neither author described the underpart secretion. Carlsson's specimen appeared to be an adult, and Carlsson noted small glandular elevations behind the vulva but did not judge these to constitute a pseudoscrotum. Vosseler [27a] noted the underpart secretion and that males possessed it in greater quantity than did females. No previous author, however, has identified the masculinization as transient. Klockenkämper [28a] identified another feature exclusive to males and juvenile females: anogenital scent marking outside (rather than only during) the mating season.
No previous hypothesis proposed to explain masculinization of female mammals appears directly applicable to the fossa. In species where increased aggression in females confers higher fitness, it has been proposed that female masculinization is a nonadaptive consequence of selection for increased androgen levels. There is, as yet, no reported evidence in the sparse literature that increased aggression confers higher fitness in female fossas. Adult females appear to have home ranges that are more exclusive than those of adult males [19a], suggesting that females may be more territorial, but this territoriality does not appear to be extreme. We found no other information on fossa aggression levels, other than from workers at Duisburg Zoo (A. Winkler, personal communication) who observed that the mother becomes aggressive towards her young when they reach 1 yr of age, that the adult female is sometimes aggressive to the adult male, and that very rarely a juvenile may become aggressive to a same-sex sibling over food.
We found no evidence that androgen levels are elevated in masculinized juvenile female fossas compared with nonmasculinized adult females (Fig. 4). In addition, levels of circulating testosterone and androstenedione were significantly lower in juvenile female fossas than in juvenile males, and the same was true in adults. Fossas thus differed from both spotted hyaenas and European moles. In spotted hyaenas, female androstenedione levels are consistently at least equal to those of males throughout the year. In European moles, testosterone levels of females approach those of males outside the reproductive season. Fossas also differ from spotted hyaenas in that, unlike young spotted hyaenas, young female fossas exhibited very little masculinization; thus, it is doubtful that the phenomenon is brought about in the fetus by elevated maternal androgens. Overall, the median androgen concentrations of adult female fossas (testosterone: 1.1 ng/ml, ≥95% CI = 0.4–1.7 ng/ml; androstenedione: 8.2 ng/ml, ≥95% CI = 4.5–15.4 ng/ml) appeared to be high relative to those in other female mammals [8a, 11a, 12a]). However, comparisons of circulating androgen levels with those presented in other studies are of limited value because there has been no cross-comparison of the diverse assay systems used.
In some mammal species, masculinization or virilization is independent of the conversion of circulating testosterone to dihydrotestosterone, such as in the male pouch young of the tammar wallaby (Macropus eugenii [29a]). For this species, it has been hypothesized that conversion of prohormones to androgens is increased within the target tissues; this hypothesis could be applied also to the fossa. Juvenile female fossas could have increased androgen receptor activity in the genital area, ventral skin, and perhaps the brain or increased 5α-reductase activity in target tissues. In the latter case, the tissue-specific conversion of testosterone to dihydrotestosterone would be increased. It is also possible that androgens are not involved in female fossa masculinization. For instance, masculinization of female neonate hyaena genitalia occurs to some extent even when treated throughout development with androgen inhibitors [30a]. Through another apparently androgen-independent process, tissue that forms the pouch of the tammar wallaby will, in the absence of two X chromosomes, develop into a scrotum [31a].
If androgen levels are not raised, the alternative explanation is that there are direct benefits of the masculinization. However, the benefits so far proposed (participation in the greeting ceremony, female dominance) apply to females in the context of a socially structured group, whereas the fossa is solitary [19a]. Furthermore, the benefit that East et al. [13a] proposed for female hyaenas, that the resulting impossibility of rape leads to beneficially submissive behavior by males, could not be expected in the fossa. Masculinized fossa females are not yet fertile; thus, males would gain no fitness advantage from being allowed to mate with them and therefore would not benefit from such behavior.
We propose instead 2 hypotheses for future testing that are more suited to the transient nature of the masculinization and to the solitary nature of the fossa. First, transient masculinization could enable juvenile female fossas to avoid sexual harassment by adult males, as in masculinized insect females [32a, 33a]. Sexual harassment is a common phenomenon in mammals, and its costs may include injuries or fatalities [34a]. Female fossas are sparsely distributed and have only a brief annual estrus. Both factors may encourage males to force copulation on any female they encounter. Juvenile females are especially vulnerable because of their small size and recent independence from the mother. A masculine appearance could allow them to escape detection or could signal to males that they are not a potential mate. In addition, the genitalia would obstruct copulation. Second, transient masculinization could enable juvenile female fossas to escape another form of aggression, that from territorial females. Radiotracking data indicate that females have exclusive ranges [19a], whereas males are less territorial. A dispersing female may be viewed as a threat by a territorial female. All females of dispersing age in our study were masculinized, which may allow them to escape detection and attack by territorial females.
Both hypotheses are based on the idea of the juvenile female benefitting from her gender being less conspicuous to a potential attacker. Neither hypothesis, however, explains what the juvenile female gains from anogenital scent marking outside the mating season, like males [28a]. Little research had been carried out on the fossa in the wild until Hawkins [19a] conducted a 2-yr study. The findings from that study and those of studies on captive individuals [20a, 21a] have provided sufficient data to reject previous hypotheses, but further research is required to test and develop more appropriate hypotheses.
We thank the Commission Tripartite of the Malagasy Government, the Université d'Antananarivo, and the Département des Eaux et Forêts for permission to work in Madagascar; our numerous field assistants, in particular Rabeantoandro Z. and Rasamison A.; Culterty Field Station, Department of Zoology, University of Aberdeen, where C.E.H. was based during the preparation of this paper; M. Fraser and H. Fraser for carrying out the hormone assays; I. Swanson and G. Barnard for advice on sample handling and steroid assay performance; EURO/DPC for donation of an androstenedione assay kit; Terry Hornsey and other staff at Suffolk Wildlife Park, U.K., for permission to examine their fossas and for valuable assistance; and 2 anonymous reviewers for comments.
1 This work was supported by the Leverhulme Trust and The Fossa Fund. 2 Correspondence: Paul Fowler, Department of Obstetrics and Gynaecology, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, U.K. FAX: 44 1224 684880; (email hidden due to site's policy) To email the author go to his/their site (HERE)
Accepted October 10, 2001.
Received June 12, 2001.
Revision received July 16, 2001.
Harrison Matthews L. The oestrous cycle and intersexuality in the female mole ( Talpa europaea Linn.). Proc Zool Soc Lond 1935 2: : 347 -383
Sánchez A, Bullejos M, Burgos M, Hera C, Stamatopoulos C, Díaz de la Guardia R, Jiménez R. Females of four mole species of genus Talpa (Insectivora, Mammalia) are true hermaphrodites with ovotestes. Mol Reprod Dev 1996 44 : 289 -294 CrossRef Medline
Harrison Matthews L. Reproduction of the spotted hyaena ( Crocuta crocuta Erxleben). Philos Trans R Soc Lond B Biol Sci 1939 230: : 1 -78
Hill OCH. Primates: Comparative Anatomy and Taxonomy IV. Edinburgh: Edinburgh University Press; 1960
Hill OCH. Primates: Comparative Anatomy and Taxonomy V. Edinburgh: Edinburgh University Press; 1962
Frank LG, Weldele ML, Glickman SE. Fitness costs of genital masculinization in female spotted hyenas. Nature 1995 377 : 584 -585 Medline
Frank LG. Evolution of genital masculinization: why do female hyaenas have such a large ‘penis'?. Trends Ecol Evol 1997 12 : 58 -62 CrossRef
Goymann W, East ML, Hofer H. Androgens and the role of female “hyperaggressiveness” in spotted hyenas ( Crocuta crocuta ). Horm Behav 2001 39 : 83 -92 CrossRef Medline
Racey PA, Skinner JD. Endocrine aspects of sexual mimicry in the spotted hyaena ( Crocuta crocuta ). J Zool Lond 1979 187 : 315 -328
Glickman SE, Frank LG, Davidson JM, Smith ER, Siiteri PK. Androstenedione may organize or activate sex-reversed traits in female spotted hyenas. Proc Natl Acad Sci U S A 1987 84 : 3444 -3447 Abstract / FREE Full Text
Glickman SE, Frank LG, Pavgi S, Licht P. Hormonal correlates of ‘masculinization' in female spotted hyaenas ( Crocuta crocuta ). 1. Infancy to sexual maturity. J Reprod Fertil 1992 95 : 451 -462 Abstract / FREE Full Text
Whitworth DJ, Licht P, Racey PA, Glickman SE. Testis-like steroidogenesis in the ovotestis of the European mole, Talpa europaea . Biol Reprod 1999 60 : 413 -418 Abstract / FREE Full Text
East ML, Hofer H, Wickler W. The erect ‘penis' is a flag of submission in a female-dominated society: greetings in Serengeti spotted hyenas. Behav Ecol Sociobiol 1993 33 : 355 -370
Gorman ML, Stone RD. The Natural History of Moles. Ithaca, NY: Comstock; 1990
Wickler W. Vom Gruppenleben einiger Säugetiere Afrikas. Mitt Max-Planck-Ges 1964 5/6 : 296 -309
Kruuk H. The Spotted Hyena. Chicago: University of Chicago Press; 1972
Lönnberg E. On the female genital organs of Cryptoprocta . Bihang K Svenska Vet-Akad Handl 1902 28 : 1 -11
Carlsson A. Über Cryptoprocta ferox . Zool Jahrb Abt Syst 1911 30: : 419 -470
Hawkins CE. Behaviour and ecology of the fossa, Cryptoprocta ferox (Carnivora, Viverridae), in a dry deciduous forest, western Madagascar. Aberdeen: University of Aberdeen; 1998. Ph.D. Thesis
Albignac R. Mammifères Carnivores. Faune de Madagascar, vol. 36. Paris: ORSTOM & CRNS; 1973
Albignac R. Breeding the fossa ( Cryptoprocta ferox ) at Montpellier Zoo. Int Zoo Yearb 1975 15 : 147 -150 CrossRef
Müllenbach R, Lagoda PJL, Welter C. An efficient salt-chloroform extraction of DNA from blood and tissues. Trends Genet 1989 5 : 391 . Medline
Dallas JF, Carss DN, Marshall F, Koepfli KP, Kruuk H, Bacon PJ, Piertney SB. Sex identification of the Eurasian otter Lutra lutra by PCR typing of spraints. Conserv Genet 2000 1 : 181 -183 CrossRef
Ridgway R. Color Standards and Color Nomenclature. Washington D.C.: Ridgway; 1912
Vosseler J. Beitrag zur Kenntnis der Fossa ( Cryptoprocta ferox Benn.) und ihrer Fortpflanzung. Zool Gart Leipzig (NF) 1929 2 : 1 -9
Klockenkämper M. Verhaltensbeobachtungen an der fossa ( Cryptoprocta ferox Bennett, 1833). Bonn, Germany: Rheinischen Friedrich-Wilhelm-Universität; 1988. Thesis
Wilson JD, George FW, Shaw G, Renfree MB. Virilization of the male pouch young of the tammar wallaby does not appear to be mediated by plasma testosterone or dihydrotestosterone. Biol Reprod 1999 61: : 471 -475 Abstract / FREE Full Text
Drea CM, Weldele ML, Forger NG, Coscia EM, Frank LG, Licht P, Glickman SE. Androgens and masculinization of genitalia in the spotted hyena ( Crocuta crocuta ). 2. Effects of prenatal anti-androgens. J Reprod Fertil 1998 113 : 117 -127 Abstract / FREE Full Text
Renfree MB, Short RV. Sex determination in marsupials: evidence for a marsupial-eutherian dichotomy. Philos Trans R Soc Lond B Biol Sci 1988 322 : 41 -53 Abstract / FREE Full Text
Cook SE, Vernon JG, Bateson M, Guilford T. Mate choice in the polymorphic African swallowtail butterfly, Papilio dardanus —male-like females may avoid sexual harassment. Anim Behav 1994 47: : 389 -397 CrossRef
Robertson HM. Female dimorphism and mating behaviour in a damselfly, Ischnura ramburi : females mimicking males. Anim Behav 1985 33 : 805 -809 CrossRef
Clutton-Brock TH, Parker GA. Sexual coercion in animal societies. Anim Behav 1995 49 : 1345 -1365 CrossRef
Fossa in different languages
Many different language fossa is spelled the same as English.
French - Fosa, Fosse
English - Fossa, Foosa, Fousa, Foussa
Russian - Фосса
Japanese - フォッサ
Italian - Il fossa, O fosa
El fosa, O fossa,
Gato fossa de Madagascar
Chinese (HK) -
Chinese (TRAD H) -
Dutch - Fretkat
Hungarian - Fossza
Bulgarian - Фоса
Esperanto - Foso
Misc - Fouche, Foosh,
Human interactionsThe fossa has been assessed as "Vulnerable" by the IUCN Red List since 2008, as its population size has probably declined by at least 30% over the last 21 years; previous assessments have included "Endangered" (2000) and "Insufficiently Known" (1988, 1990, 1994). The species is dependent on forest and thus threatened by the widespread destruction of Madagascar's native forest, but is also able to persist in disturbed areas. A suite of microsatellite markers (short segments of DNA that have a repeated sequence) have been developed to help aid in studies of genetic health and population dynamics of both captive and wild fossas. Several pathogens have been isolated from the fossa, some of which, such as anthrax and canine distemper, are thought to have been transmitted by feral dogs or cats.
Although the species is widely distributed, it is locally rare in all regions, making them particularly vulnerable to extinction. The effects of habitat fragmentation increase the risk. For its size, the fossa has a lower than predicted population density, which is further threatened by Madagascar's rapidly disappearing forests and dwindling lemur populations, which make up a high proportion of its diet. The loss of the fossa, either locally or completely, could significantly impact ecosystem dynamics, possibly leading to over-grazing by some of its prey species. The total population of the fossa living within protected areas is estimated at less than 2,500 adults, but this may be an overestimate. Only two protected areas are thought to contain 500 or more adult fossas: Masoala National Park and Midongy-Sud National Park, although these are also thought to be overestimated. Too little population information has been collected for a formal population viability analysis, but estimates suggest that none of the protected areas support a viable population. If this is correct, the extinction of the fossa may take as much as 100 years to occur as the species gradually declines. In order for the species to survive, it is estimated that at least 555 km2 (214 sq mi) is needed to maintain smaller, short-term viable populations, and at least 2,000 km2 (770 sq mi) for populations of 500 adults.
Taboo, known in Madagascar as fady, offers protection for the fossa and other carnivores. In the Marolambo District (part of the Atsinanana region in Toamasina Province), the fossa has traditionally been hated and feared as a dangerous animal. It has been described as "greedy and aggressive", known for taking fowl and piglets, and believed to "take little children who walk alone into the forest". Some do not eat it for fear that it will transfer its undesirable qualities to anyone who consumes it. However, the animal is also taken for bushmeat; a study published in 2009 reported that 57% of villages (8 of 14 sampled) in the Makira forest consume fossa meat. The animals were typically hunted using slingshots, with dogs, or most commonly, by placing snare traps on animal paths. Near Ranomafana National Park, the fossa, along with several of its smaller cousins and the introduced small Indian civet (Viverricula indica), are known to "scavenge on the bodies of ancestors", which are buried in shallow graves in the forest. For this reason, eating these animals is strictly prohibited by fady. However, if they wander into villages in search of domestic fowl, they may be killed or trapped. Small carnivore traps have been observed near chicken runs in the village of Vohiparara.
Fossas are occasionally held in captivity in zoos. They first bred in captivity in 1974 in the zoo of Montpellier. The next year, at a time when there were only eight fossas in the world's zoos, the Duisburg Zoo acquired one; this zoo later started a successful breeding program, and most zoo fossas now descend from the Duisburg population. Research on the Duisburg fossas has provided much data about their biology.
The major threat to this species is loss and fragmentation of forest habitat,  largely caused by the conversion of forested areas to agricultural land and pasture and selective logging. It also preys on domestic fowl and is consequently killed as a pest species by local people. It is very susceptible to hunting, and is often targeted by groups engaged in collective group hunting (e.g. in the Makira forests) specifically for the purpose of eradication. Parts of this species are also used for medicinal purposes. Competition with feral carnivores also occurs, including predation by feral dog packs.
Forest logged for subsistence agriculture in Madagascar.
 This species is listed on Appendix II of CITES. It is present in many protected areas throughout Madagascar (such as Kirindy Forest, and Ranomafana, Masaola, and Ankarafantsika National Parks). It is the subject of a successful ex situ captive breeding programme. Better protection of intact forests and awareness programmes concerning the value of this species for pest control are needed. This species is not currently protected adequately under national legislation, as there are conflicts within national legislation, as well as within and between local community laws. Morphometrics, diet, and conservation of Cryptoprocta ferox 
by Dollar, Luke Jay, PhD, DUKE UNIVERSITY, 2006, 0 pages; 3267903
Abstract: Cryptoprocta ferox is Madagascar's largest endemic carnivore. Its natural history, ecology, and behavior are little studied. This dissertation, following an introduction to Cryptoprocta as an organism, focuses on this species' (1) morphometrics, sexual dimorphism, and related selective pressures; (2) diet and the relationship between predators and prey behaviors; (3) habitat status, introducing a new evaluation technique for management projects; and (4) conservation threats, based on the case study of Ankarafantsika National Park. I present the first comparative data on the morphology of Cryptoprocta, within and between genders and across two dry forest research sites in North and Western Madagascar. I test hypotheses regarding sexual dimorphism in Cryptoprocta, based on numerous anatomical measurements. This analysis explores differences in morphology of Cryptoprocta between the two sites, examining ecological catalysts for similarities or differences encountered at these completely isolated locations. In areas of higher male density, I demonstrate an increasing sexual size dimorphism. This dissertation also focuses on the dietary habits of Cryptoprocta in Ankarafantsika National Park, Madagascar. I examine scats from two sites within Ankarafantsika, from both the wet and dry seasons, for prey content. With these data, I test the hypothesis that Cryptoprocta is a specialist predator of lemurs. They are not, appearing to be remarkably flexible in their dietary habits—while still incorporating a substantial number of easily captured primates as prey items. In chapter four, I propose and implement a novel method of evaluating success or failure in the maintenance and conservation of protected forests (and, de facto, habitat used by Cryptoprocta). Using satellite imagery, I quantify the amount of forest maintained or lost during the tenure of a conservation program, with actual values representing the relative management effectiveness. Cryptoprocta populations in Madagascar's dry forests face much greater habitat conservation challenges than those in rain forests, over the past decade. Finally, I specifically examine the management practices of Ankarafantsika National Park, the base of operations for most of my fossa research. In conclusion, I provide suggestions for better conservation and management of fossa populations in Ankarafantsika National Park.
Current population was estimated to be 2,500 in the wild but it is not known how many there are out there today. Conservationists / Preservationists Dr Luke Dollar
Luke Dollar, a graduate student at the University of Tennessee, who is studying these strange creatures in Ankarafantsika National Park. The explanation for the strange appearance of fossas and other Madagascar animals goes back some 160 million years ago in geologic time. That's when Madagascaran island about one and a half times the size of California broke away from Africa and drifted off like a giant ark. Only dinosaurs and a few primitive birds and mammals were on board. Later, the mainland ancestors of primates and a few other animal groups made it to the island, probably by rafting on floating logs or vegetation. Because there were no monkeys, rabbits, horses, antelopes, pigs, cats or dogs there, the castaways found just about every niche up for grabs. With no other carnivores around, mongooses and civets became Madagascar´s predators, and the fossa filled the hunting niche usually occupied by cats. At one time, scientists believed the fossa actually was a primitive cat because it seemed to have so many feline characteristics. But recent DNA studies have confirmed that it is actually more closely related to the mongoose. Large eyes, retractable claws and long, daggerlike canine teeth make the fossa a formidable hunter. For a 22-to-26-pound animal, it is amazingly agile in trees. Its low-slung body, powerful limbs and extra-long tail help it balance and jump. "Fossas can leap from one tree to another, land head down on the trunk, then swarm down the tree head first like a squirrel," says Dollar. Fossas are found throughout the island wherever there is forest, but they are rare, and their numbers are unknown.
"For the past eleven years, Earthwatch volunteers helped us study the enigmatic carnivore of the Red Island, the fossa. The fossa is the top predator of the Malagasy food chain, but we know so little about it that scientists still argue about how few of these extraordinary predators remain. With its cat-like weaponry and the tenacity of a mongoose, it is certain that the fossa is one of the most capable mammalian predators on Earth. Join us in this adventure to learn as much as possible about the fossa, to protect it and its ecosystem."
Luke measuring the fossa's teeth.
One of Luke Dollar's colleague bringing a fossa back in to the wild.
Fossa getting released.
Mia-Lana Lührs PhD student of the department of Sociobiology/Anthropology at the University of Göttingen.
"I found out about fossas only by coincidence. When I was working in a zoo, I became familiar with the European Endangered Species Program (EEP). Searching these programs on the web, I came to the website of Duisburg Zoo where the fossa's EEP is managed. When I saw the pictures of the fossas on that page, I was absolutely puzzled that I had never heard of this species before, although I have always been interested in carnivores. I couldn't even tell which family of carnivore this one might belong to," Mia-Lana Lührs, a PhD student at the University of Göttingen in Germany, told mongabay.com. Despite such a puzzling introduction to Madagascar's biggest predator, Lührs has become one of the world's foremost experts on the enigmatic animal.
Lührs says that fossas may have been, in part, neglected by conservationists and researchers for so long, because of the "dominance of primatological research (i.e. lemurs) in Madagascar […] in fact, fossas are such fascinating creatures that they should be popular all around the world despite their limited distribution."
A zookeeper feeding a captive fossa.
In captivity , the fossa consumes between 800 and 1000 grams (28 and 35 oz) of meat a day.
Fossas can live up to 20 or more than 20 years in captivity.
Their maximum lifespan is 23.1 years (captivity).  Zoos In captivity, fossas are usually not aggressive and sometimes even allow themselves to be stroked by a zookeeper, but adult males in particular may try to bite.  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.
Fossas should be in large enclosures to prevent them from becoming bored and anxious. Bored animal will become unhappy and move back and forth and or moving side to side repetitively, doing repetitive movement are sign of unhappiness. The only solution for this problem are larger enclosures and
environmental enrichment so the animal can be more active, play a lot and be happy. In conclusion: I'm no zookepper nor biology but I know a lot about captive animal and know a lot about the fossa and other animals.
Fossa "Forsell" playing with a bag.
Fossa playing with a water container or something.
and large enclosure with a lot of trees and nature like as possible will make the captive animal healthier and happier.
Behavioural enrichment is important as the fossa is an active animal. Food is hidden around the enclosure, sometimes being hoisted up onto poles, so that the fossa has to search and climb for it.
Also zoo plays a role in helping saving species from extinction by breeding them.
Fossa playing with a zookeeper.
Fossa seems to be very playful animal. Exotic pet Fossas used to be kept as exotic pets
Walter's World of Pets used to sell fossa as pet until the CITES banned the export of fossas. Previously, the fossa was listed as 'vulnerable'. The fossa is listed as a [Convention on the International Trade in Endangered Species of Wild Flora and Fauna] (CITES) Appendix II animal, which puts restrictions on its export and trade. Walter's World is a Texan exotic petshop which formerly sold fossas as pet.  Fossa picture from Walter's World, very, very old picture. Probably one of the last exotic fossa before Walter's world stopped selling fossas when the CITES put restrictions or banned the export of fossas.
It started at about 5,000$, then rose to 7,000$ and shortly after they've stop selling fossas as exotic pet. Which zoos has the fossa? This will give the name and the link to the zoo that has a captive fossa or fossas.
Also the recommandation is if you're planning any trips to those zoos is email the zoo and ask them if they have the animal before you go.
The modern mongoose and the fossa evolved from the same ancestor, which arrived on Madagascar about 21 million years ago.
The fossa is pretty odd creature that is in the viverrids family. Looks like across a dog, cat, hyena, puma and jaguarundi.
Its name derived from a native Malagasy word, and pronounced "foosh," this puzzling animal is as worthy of biodiversity poster status as the more famous lemurs of Madagascar.
The fossa is the largest of all mongoose species, with an adult head-and-body length of 24 to 31.5 inches (61 to 80 centimeters), a tail as long as the head and body, and an adult weight of eleven to twenty pounds (5 to 10 kilograms). A fossa looks like a combination of dog, cat, and mongoose, and has retractable claws, like a cat's, something not seen in other mongoose species. If approaching head-on, a fossa gives the impression of a scaled-down puma, but a side view shows the snout to be longer than that of the true cats, but shorter and wider than the norm among mongoose species. The gray-brown nostril pad Fossas are the largest native predator of Madagascar. (Photograph by Harald Schütz. Reproduced by permission.) is furless and prominent, like a dog's. The overall appearance and behavior suggests a cat rather than a dog.
The body is long and sleek and the legs are short but powerful, as in a mongoose. The coat color is rich reddish-brown, the undersides lighter but stained with an orange secretion from skin glands. This secretion is more abundant in males than in females. There are five padded digits on each of the four feet. Though its movements are often considered plantigrade, meaning that the entire foot, from the toetips to the back of the heel, touch the ground when walking, fossas have also been seen to walk digitigrade, that is, only on the toetips. The large, prominent eyes are brown and lustrous, and have pupils that can retract to vertical slits, as in cats. The ears are large, prominent, and narrower than in typical mongoose species.
The fossa was originally classified as a direct descendant, little changed, of the ancestor species that gave rise to cats (Felidae) and dogs (Canidae). That classification arose from both to the appearance of the fossa and to the notion that Madagascar was a natural refuge for primitive mammal species driven to extinction elsewhere by more advanced species. At the same time, the fossa is the living creature closest in form to the dog-cat ancestor. Its classification is still uncertain. Genetic comparison studies strongly support the fossa and the other Malgasy mammal carnivores as being descendants, having changed forms over the ages through adaptive evolution, of a single colonizing species of mongoose. The founder species must have floated from Africa to Madagascar twenty to thirty million years ago. The fossa is the end result of adaptive evolution by which a mongoose, over countless generations, became something like a cat. At the same time, the fossa keeps a number of mongoose-like features. Scientists have found remains of a larger species related to the fossa, since named Cryptoprocta spelea.
Wild fossa walking. Possible long term future evolution I am pretty sure the fossa in many millions of years into the future may continue to evolve.
This is what the fossa of today looks like.
Fossa man (click to enlarge the pic).
What fossa could potentially look in the distance future if they evolve into bipedal intelligent beings. Disclaimer: It does not guarantee what they may or will look or how they would act/behave in the distance future if they evolve into bipedal or not species. I'm an individual and I have a mind of my own. So in my personal belief and or theory all animal will evolve into bipedal intelligent creatures and form their own civilization, culture, philosophies, religion and more.
We evolved ape to man so it means all animal someday will evolve animal
to something similar.
^ a b c Hawkins, C.E.; Racey, P.A. (2005). "Low population density of a tropical forest carnivore, Cryptoprocta ferox : implications for protected area management". Oryx 39 (1): 35–43. doi : 10.1017/S0030605305000074 .
^ Lührs, M.-L.; Dammhahn, M. (2009). "An unusual case of cooperative hunting in a solitary carnivore". Journal of Ethology 28 (2): 379–383. doi : 10.1007/s10164-009-0190-8 .
^ Wright, P.C.; Heckscher, S.K.; Dunham, A.E. (1997). "Predation on Milne Edward's sifaka ( Propithecus diadema edwardsi ) by the fossa ( Cryptoprocta ferox ) in the rainforest of southeastern Madagascar". Folia Primatologica 68 (1): 34–43. doi : 10.1159/000157230 .
^ a b Hawkins, C.E.; Racey, P.A. (2008). "Food habits of an endangered carnivore, Cryptoprocta ferox , in the dry deciduous forests of western Madagascar". Journal of Mammalogy 89 (1): 64–74. doi : 10.1644/06-MAMM-A-366.1 .
lefossa.org : le site de référence francophone sur le fossa
11 mai 2005 ... Informations sur le plus grand prédateur de l'île de Madagascar (dont il est une espèce endémique), inscrit sur la liste rouge des espèces menacées de l'UICN. Retrieved 09 March 2011 .
Longevity, ageing, and life history of Cryptoprocta ferox
Genus: Cryptoprocta. Species, Cryptoprocta ferox. Common name, Fossa. Lifespan, ageing, and relevant traits. Maximum longevity, 23.1 years (captivity) ... genomics.senescence.info/species/entry.php?...Cryptoprocta_ferox. Retrieved in 10 March 2011 .
Mongooses and Fossa: Herpestidae - Fossa (cryptoprocta Ferox)
The fossa is the end result of adaptive evolution by which a mongoose
over countless generations, became something like a cat. At the same time, the fossa
is the living creature closest in form to the dog-cat ancestor. Retrieved 11 March 2011 .
Gursky, S.L.; Nekaris, K.A.I., eds (2007). Primate Anti-Predator Strategies (Developments in Primatology: Progress and Prospects) . Springer. ISBN 978-0-387-34807-0 .
Dollar, L.; Ganzhorn, J.U.; Goodman, S.M. (2007). "Primates and other prey in the seasonally variable diet of Cryptoprocta ferox in the dry deciduous forest of Western Madagascar". pp. 63–76. doi : 10.1007/978-0-387-34810-0 .