A still from the new video shows Cross River gorillas in their forest home.

The rarest gorilla on Earth, the elusive Cross River gorilla, has been caught on film by a hidden camera trap for the first time ever.

Researchers estimate that only about 250 to 300 of the gorillas remain on the planet, and humans have rarely observed these critically-endangered primates in their natural habitat.

The two-minute footage shows eight of the gorillas making their way through a forest in Cameroon. The video offers a glimpse of classic gorilla behavior, yet also reveals the plight of the threatened apes.

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

In a movie-worthy moment (at about 1:10 in the video), a massive silverback gorilla suddenly races along the forest path, beating his chest.

Seconds later (at about 1:18), another gorilla lopes across the frame; the animal is missing a hand. The wound appears to be healed, but could have been caused by a hunter's trap, according to a statement from the Wildlife Conservation Society, the group that captured the rare gorilla video with one of four camera traps set up in the Kagwene Gorilla Sanctuary.

"Cross River gorillas occur in very low densities across their entire range, so the appearance of a possible snare injury is a reminder that continued law enforcement efforts are needed to prevent further injuries to gorillas in the sanctuary," Liz Macfie, gorilla coordinator for WCS's Species Program, said in a statement.

Although local people don't hunt the gorillas directly, traps set for other forest animals can sometimes injure the apes.

Cross River gorillas are extremely shy, and typically flee at the first sight of humans. They are the rarest of the four gorilla subspecies, and live only in the mountain forests that straddle the border of Cameroon and Nigeria.

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