You're not likely to see a Cross River gorilla in person, but you can see a whole troop in a series of rare photos. Cross River gorillas are the most endangered subspecies of ape, with only 300 known to live in the wild, reports the BBC. The gorillas—which have smaller heads, longer arms, and lighter-colored hair than their cousins—are known to inhabit a remote, 4,600-square-mile mountainous area in Nigeria and Cameroon, but they're rarely observed, per the Guardian. That's one of the reasons conservationists are so excited about the photos snapped by camera traps in the Mbe Mountains of southern Nigeria this year. Another is that the photos show infants of varying age.
Three black-and-white photos, taken in January and May, show infants riding on the back of adults. A color photo, taken June 22, shows the same scene, though with other gorillas crowded in the frame. The gorillas were last captured in images from Cameroon's Kagwene Gorilla Sanctuary in 2012, per CNN. The Wildlife Conservation Society Nigeria hopes this implies that the gorilla population—once thought to have gone extinct due to poaching—is experiencing a resurgence. "It is extremely exciting to see so many young Cross River gorillas," Inaoyom Imong, director of the WCS Nigeria's Cross River gorilla project, tells the Guardian. But he adds "the threat of hunting remains, and we need to continue to improve the effectiveness of our protection efforts." (Read more gorilla stories.)