Pedro Narra / Mountain Gorilla (Goriila beringei) resting, Volcanoes National Park, Virunga Mountains, Rwanda.

Eric Baccega / Mountain gorilla (Gorilla beringei beringei) juvenile female stretching hand out towards camera, member of the Kabirizi group, Virunga National Park, North Kivu, Democratic Republic of Congo, Africa,...

Jabruson Motion / National park guards and trackers transporting a dead silverback Mountain gorilla (Gorilla beringei beringei), Bukima, Virunga National Park, Democratic Republic of Congo, 1996.

Jabruson Motion / Three juvenile Mountain gorillas (Gorilla beringei beringei) resting in vegetation, rolling and playing before approaching camera, Bukima, Virunga National Park, Democratic Republic of Congo, 1996.

Jabruson Motion / Close-up of a male Mountain gorilla (Gorilla beringei beringei) looking at camera, pulls off lens component, Bukima, Virunga National Park, Democratic Republic of Congo, 1996.

Jabruson Motion / Close-up of a female Mountain gorilla (Gorilla beringei beringei) feeding, gets up and rolls into new resting position near other family members, Bukima, Virunga National Park, Democratic Republic of...

Jabruson Motion / Female Mountain gorilla (Gorilla beringei beringei) getting up from resting and eating, twirls around before settling down into a new resting position, Bukima, Virunga National Park, Democratic Republ...

Jabruson Motion / Silverback Mountain gorilla (Gorilla beringei beringei) and family resting in vegetation, with a juvenile peering into the camera lens Bukima, Virunga National Park, Democratic Republic of Congo, 1996...

Jabruson Motion / Close-up of a male Mountain gorilla (Gorilla beringei beringei) and juvenile resting, captivated by reflection in camera lens, knocks juvenile over, Bukima, Virunga National Park, Democratic Republic...

Jabruson Motion / Close-up of a female Mountain gorilla (Gorilla beringei beringei) looking at camera, scratches face, Bukima, Virunga National Park, Democratic Republic of Congo, 1996.

Jabruson Motion / Close-up of a male Mountain gorilla (Gorilla beringei beringei) looking at camera, with another male approaching from behind, beats chest displaying, Bukima, Virunga National Park, Democratic Republic...

Jabruson Motion / Wide angle shot of a juvenile Mountain gorilla (Gorilla beringei beringei) swinging from a branch and looking at camera, with a silverback nearby, Bukima, Virunga National Park, Democratic Republic of...

Jabruson Motion / Close-up of a tracker, shot pans to a silverback Mountain gorilla (Gorilla beringei beringei) looking at camera, Bukima, Virunga National Park, Democratic Republic of Congo, 1996.

Eric Baccega / View of the lava lake in Nyiragongo volcano at night, Virunga National Park, Democratic Republic of Congo.

Fiona Rogers / Mountain gorilla (Gorilla gorilla beringei) female portrait, member of 'Humba' group . Virunga National Park, Democratic Republic of Congo, March.

Fiona Rogers / Mountain gorilla (Gorilla gorilla beringei) female portrait , part of the 'Munyanga' group. Virunga National Park, Democratic Republic of Congo, March.

Fiona Rogers / Mountain gorilla (Gorilla gorilla beringei) silverback male feet, member of 'Humba' group. Virunga National Park, Democratic Republic of Congo, March.

Fiona Rogers / Mountain gorilla (Gorilla gorilla beringei) infant portrait, member of 'Humba' group. Virunga National Park, Democratic Republic of Congo, March.

Fiona Rogers / Mountain gorilla (Gorilla gorilla beringei) female portrait, member of 'Humba' group . Virunga National Park, Democratic Republic of Congo, March.

Anup Shah / Mountain gorilla (Gorilla gorilla beringei) infant portrait, member of 'Humba' group. Virunga National Park, Democratic Republic of Congo, March.

Christophe Courteau / Steam rising from the crater of Nyiragongo Volcano. Virunga National Park, North Kivu Province, Democratic Republic of Congo. September 2015.

Christophe Courteau / Lava Lake at night in the crater of Nyiragongo Volcano, Virunga National Park, North Kivu Province, Democratic Republic of Congo. September 2015.

Christophe Courteau / Lava Lake at night in the crater of Nyiragongo Volcano, Virunga National Park, North Kivu Province, Democratic Republic of Congo. September 2015.

Jabruson Motion / Close up portrait of a female Mountain gorilla (Gorilla beringei beringei) seen through foliage, with an infant appearing and looking at the camera, Bukima, Virunga National Park, North Kivu, Democrat...

Jabruson Motion / Close up of a baby Mountain gorilla (Gorilla beringei beringei) looking at the camera before leaving the frame, part of the À™NyakamweÓ family group, Bukima, Virunga National Park, North Kivu, Democ...

Jabruson Motion / Silverback Mountain gorilla (Gorilla beringei beringei) from the 'Nyakamwe' family group looking at the camera before sitting back, Bukima, Virunga National Park, North Kivu, Democratic Republic of Co...

Jabruson Motion / Female Mountain gorilla (Gorilla beringei beringei) with juvenile walking through foliage before a silverback enters the frame and looks at the camera, Bukima, Virunga National Park, North Kivu, Democ...

Tom Gilks / Nyiragongo volcano at night, Virungas National Park, Democratic Republic of Congo February 2014.

Jabruson / Eastern gorilla (Gorilla beringei beringei) juvenile confiscated from poachers by national park authorities from poachers, awaiting release to the wild in wooden crate, Djomba, Virunga National Park,...

Jabruson / Eastern gorilla (Gorilla beringei beringei) confiscated juvenile recovered by National Park authorities from poachers, awaiting release to the wild in wooden crate, with hand reaching out, Djomba, Vir...

Jabruson / Hippopotamuses fighting (Hippopotamus amphibius) taken before major crash in numbers in the 1990s due to political instability and hunting. Rwindi sector of the Virunga National Park. North Eastern Za...

Jabruson / Young Chimpanzee in fruiting fig tree (Pan troglodytes schweinfurthii) Tongo, Virunga National Park, Kivu, Democratic Republic of Congo

Christophe Courteau,Christophe Courteau / Villagers walking along a road during a heavy rain shower, Virunga National Park, North Kivu Province, Democratic Republic of the Congo, August 2010.

Andy Rouse / View from the undergrowth looking up into the canopy of rainforest; prime Gorilla (Gorilla beringei) habitat of the Susa group on the upper slopes of Karisimbi Volcano. Virunga Volcanoes National Park...

Andy Rouse / Virunga Volcanoes National Park at dawn. Rwanda, Africa, April 2010.

Andy Rouse / Harvested potatoes in Virunga Volcanoes National Park with agricultural land behind and forest beyond where the mountain gorillas live, Rwanda, April 2010. Encroachment of the human population on habi...

Suzi Eszterhas / Mountain gorilla (Gorilla gorilla berengei) infant sitting on mothers head while she feeds on vegetation, Virunga Volcanoes National Park, Rwanda

Suzi Eszterhas / Female Mountain gorilla (Gorilla gorilla berengei) licking finger after cleaning herself, Virunga Volcanoes National Park, Rwanda

Suzi Eszterhas / Female Mountain gorilla (Gorilla gorilla berengei) picking nose, Virunga Volcanoes National Park, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback portrait, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) juvenile hanging from branch, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) close up of eye, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback male scratching head, drunk on bamboo shoots, Volcanoes NP, Virunga mountains, Rwanda Note - if gorillas eat an excess of bamboo shoots they ca...

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback male playing in habitat, drunk on bamboo shoots, Volcanoes NP, Virunga mountains, Rwanda Note - if gorillas eat an excess of bamboo shoots they...

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) close up of feet showing toe curled around branch, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback moving through habitat, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback, face portrait, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Parc National des Volcans / Volcanoes NP, Virunga Mountains, Rwanda, Africa, habitat of the Mountain gorillas