Fossa (animal) - Human Interactions

Human Interactions

The 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 fossas 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, France. The next year, at a time when there were only eight fossas in the world's zoos, the Duisburg Zoo in Germany 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.