A camera placed in a forest in Cameroon has captured rare footage of a band of Cross River gorillas - one of the most elusive species on earth - in their natural habitat.

The two minutes of footage posted to YouTube by the Wildlife Conservation Society shows a troop of eight Cross River gorillas. Researchers say the number of the critically endangered primates has dwindled to only 250 to 300 left on the planet.

Found mostly on the border between Nigeria and Cameroon, the Cross River gorilla, which is a subspecies of the Western gorilla, is the most endangered of the African apes.

"The footage provides us with our first tantalizing glimpses of Cross River gorillas behaving normally in their environment," Christopher Jameson, director of the Takamanda Mone Landscape Project, told OurAmazingPlanet.com. "A person can study these animals for years and never even catch a glimpse of the gorillas, much less see anything like this."

At one exhilarating moment in the footage, a silverback gorilla beats his chest as he races across the static shot. Another gorilla walks across the screen seconds later displaying a missing hand, which might have been lost when caught in a trap.

Cross River gorillas are extremely shy, and are known to flee at the first sight of a human, hence the lack of footage of the species. Hunting them for bush meat and a loss of their natural habitat has led to their decline in numbers. In an attempt to protect the gorillas, Cameroon's government created the Takamanda National Park in 2008.

The Wildlife Conservation Society released a statement saying that the group that captured the new footage with one of four camera traps set up in the Kagwene Gorilla Sanctuary.