By Matt Walker
Editor, Earth News
A deft climber
It is one of the most unusual of all big predators, but the odd-looking, cat-like fossa, the largest carnivore on the island of Madagascar, faces an uncertain future.
Few fossa can now be found in a place that was once a stronghold, as villagers hunt the animal as bushmeat and in a bid to protect their own livestock, which the fossa eats.
Its population may be declining rapidly, says one of the few scientists to have studied it in the wild, and it could already be critically endangered.
Fossa are a highly specialised predator.
Secretive and cat-like, they are expert climbers and well equipped for chasing down lemurs in the forest, preying on even the largest lemur species.
There is this fascinating weird creature at the other end of the world and it might soon go extinct
Fossa expert Mia-Lana Lührs
But they also take small shrew-like creatures called tenrecs and almost any other vertebrate animal living in Madagascar's forests, with the exception of humans, crocodiles and possibly wild boar.
However, very little is known about them, as only a handful of scientists have been able to study fossa closely in the wild.
For example, it was once thought to be closely related to civets and their relatives, but genetic evidence suggests it is actually related to other Malagasy carnivores that together are related to mongooses.
Little is also known about how many fossa exist on Madagascar, with official estimates suggesting that fewer than 2500 survive and the animal should be considered as Endangered.
But according to one scientist studying it, the fossa could be in an even more perilous state.
Ms Mia-Lana Lührs is currently studying the fossa for her PhD at Germany's University of Göttingen and the German Primate Center.
She has also helped the upcoming BBC natural history series Madagascar film the creatures in the wild.
Within the past three years, she has recorded a substantial fall in the numbers of fossa living in Kirindy, a reserve within forests on the west of the island.
This area was considered to be a stronghold of the fossa.
In 2007, Ms Lührs recorded 18 different males regularly visiting a particular tree that male and female fossa use to mate in.
In 2008, she recorded 14 males, and in 2009 just ten.
Last year, only two males were sighted.
"Fortunately, I have seen seven males shortly before in another part of the forest where I observed, so I know that at least nine males are still alive," she told BBC News.
But overall, her studies, which use GPS tracking collars to follow individual fossa, suggest no more than 30 fossa of either sex now exist in Kirindy.
A forest fragment that size would be expected to be home to many times that number.
"That is not sufficient for the population to survive without management," she says.
Habitat destruction is one significant cause of the fossa's recent decline reason.
But the large predator is also coming into conflict with people, as it leaves the dwindling forest in search of food.
A survey conducted last year by colleague Moritz Rahlfs in villages surrounding Kirindy found that 12 fossa had been killed recently by people living in just eight villages, to prevent the fossa from stealing their chickens.
"If the killings continue at such high rates, we have three years left to see fossas in Kirindy," says Ms Lührs.
The carnivore also faces other threats.
A separate recent piece of research by PhD student Christopher Golden of the University of California, Berkeley, has already found that fossa are hunted for food by people within 55 to 60% of those villages studied in northeastern Madagascar.
Fossa body parts are also used in traditional medicines in some parts of the island.
Ms Lührs suspects the fossa may already be critically endangered.
"There is this fascinating weird creature at the other end of the world and it might soon go extinct," she says.
The story of the fossa will be told in the natural history series Madagascar, which broadcasts on BBC Two on Wednesday 9 February at GMT 20.00.