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

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

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.

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

Andy Rouse / Mountain gorilla (Gorilla beringei) silverback walking in front of watching tourists, Virunga Volcanoes, Rwanda 2012. No release available.

Andy Rouse / Virunga Volcanoes National Park at dawn. Rwanda, Africa, April 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 / 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 / Parc National des Volcans / Volcanoes NP, Virunga Mountains, Rwanda, Africa, habitat of the Mountain gorillas

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback moving through habitat, 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) blackback male in rainforest, in front of Sabinyo volcano, Volcanoes NP, Virunga mountains, Rwanda (non-ex)

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback watching through forest, Virunga Mountains, Volcanoes NP, Rwanda (non-ex)

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) juvenile hanging from branch, 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) mother and baby with hairy head, Volcanoes NP, Virunga mountains, Rwanda

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) mother cradling and kissing foot of 1 week baby, Volcanoes NP, Virunga Mountains, Rwanda

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) silverback, face portrait, Volcanoes NP, Virunga mountains, Rwanda

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

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) baby with hairy head, Volcanoes NP, Virunga mountains, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) mother with young and silverback male in background, Volcanoes NP, Virunga Mountains, Rwanda

Jabruson / Lava flow and corresponding fire moving through forest, Kimanura volcanic eruption, Virunga NP, Democratic Republic of Congo.

Jabruson / Lava explodes from active volcano, Kimanura eruption, Virunga NP, Democratic Republic of Congo (formerly Zaire)

Jabruson / Deforestation for fuel by Hutu refugees. Virunga NP. Democratic Republic of Congo. 900 tons of wood cleared per day.

Jabruson / Muhavura volcano viewed from Tongo. Sunset. Virunga NP, Democratic Republic of Congo.

Jabruson / Lava flow destroying trees and vegetation. Kimanura volcano. Virunga NP, Democratic Republic of Congo.

Jabruson / Kimanura eruption, Virunga NP, Democratic Republic of Congo.

Jabruson / Volcanic eruption , Kimanura volcano, Virunga NP, Democratic Republic of Congo.

Jabruson / Lava flow from the Kimanura volcano, Virunga NP, Democratic Republic of Congo.

Jabruson / Kimanura eruption. Virunga NP active volcanic region, Democratic Republic of Congo.

Jabruson / Kimanura eruption. Virunga NP active volcanic region, Democratic Republic of Congo.

Jabruson / Kimanura eruption. Virunga NP, Rep of Congo (formerly Zaire), Central Africa

Jabruson / Deforestation for fuel by Hutu refugees (900 tons wood per day). Virunga NP (Mikeno and Karisimbi volcanoes), Democratic Republic of Congo.

Jabruson / Red hot lava flow from Kimanura volcano eruption, Virunga NP, Dem Rep of Congo 1989 Africa

Jabruson / Lava flow from the Kimanura volcano, Virunga NP, Democratic Republic of Congo.

Pedro Narra / Mountain Gorilla (Goriila beringei) infant with wet fur, Volcanoes National Park, Virunga Mountains, Rwanda.

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

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

Pedro Narra / Mountain Gorilla (Goriila beringei) baby riding on mothers back, Volcanoes National Park, Virunga Mountains, Rwanda.

Pedro Narra / Mountain Gorilla (Goriila beringei) close up of eyes, Volcanoes National Park, Virunga Mountains, Rwanda.

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

Christophe Courteau / Sabyinyo Volcano with agricultural land on boundary of Volcanoes National Park, Virunga Mountains, Rwanda.

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) silverback Gihishamwotsi displaying, Sabyinyo Group. Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) silverback Gihishamwotsi displaying, Sabyinyo Group. Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) blackback Shirimpumu displaying, non dominant male, Sabyinyo Group, Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) close up of silverback eating, Volcanoes National Park, Virunga Montains, Rwanda.

Christophe Courteau / Orchids among vegetation in the Volcanoes National Park, home of the Mountain gorillas (Gorilla gorilla beringei), Virunga Mountains, Rwanda

Christophe Courteau / Mist over tropical rainforest covered slope of the Visoke Volcano, home to Mountain gorillas (Gorilla gorilla beringei) Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Natural habitat of the Mountain gorilla (Gorilla gorilla beringei) Volcanoes National Park, Virunga Mountains, Rwanda in rainy season

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) head portrait of Silverback Gihishamwotsi, non group dominant, Sabyinyo Group, Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) silverback Gihishamwotsi displaying, non group dominant, Sabyinyo Group, Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) silverback Gihishamwotsi displaying, non group dominant, Sabyinyo Group, Volcanoes National Park, Virunga Mountains, Rwanda

Christophe Courteau / Mountain gorillas (Gorilla gorilla beringei) confrontation between two dominant silverback males from two different family groups - Agashyia and Sabiniyo. Volcanoes National Park. Virunga Mountains, R...

Christophe Courteau / Mountain gorilla (Gorilla gorilla beringei) non dominant male challenging silverback Akurevuro, Kwitonda Group. Volcanoes National Park, Virunga Mountains, Rwanda.

Eric Baccega / Mount Nyiragongo smoking - one of several active volcanoes in the Virunga Massif Volcano Range, Democratic Republic of Congo, Africa. July 2016

Eric Baccega / Lava lake at night in the crater of Nyiragongo Volcano, Virunga National Park, North Kivu Province, Democratic Republic of Congo

Will Burrard-Lucas / Long exposure of star trails over Virunga volcanoes seen from Bwindi Impenetrable National Park, Uganda. November

Christophe Courteau / Virunga National Park guard at twilight, with balaclava for warmth and gun, 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.

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

Pedro Narra / Mountain gorilla (Gorilla berengi) mother suckling young, Volcanoes National Park, Virunga Mountains, Rwanda. April.

Jabruson / Virunga Massif Volcano Range (from left to right: Mount Visoke, Mount Karisimbi and Mount Mikeno) and adjoining forests, isolated and surrounded by human habitation and agriculture. Democratic Republi...

Jabruson / 'The Virunga Massif Volcano Range': Mount Karisimbi viewed from Tongo, Southern Sector of Virunga National Park, Democratic Republic of Congo. September 1993

Jabruson / Dawn scenic of Mount Mikeno viewed from Tongo. An extinct volcano in the Southern Sector of the Virunga National Park. Part of 'The Virunga Massif Volcano Range', Democratic Republic of Congo. Septemb...

Jabruson / Mount Nyiragongo - smoking active volcano in the Southern Sector of the Virunga National Park. One of several active volcanos in 'The Virunga Massif Volcano Range', Democratic Republic of Congo. Septe...

Christophe Courteau / Sunrise behind Mount Mikeno, with Mount Karisimbi in the bakground, Virunga National Park, Democratic Republic of the Congo, August 2010.

Christophe Courteau / Sunrise behind Mount Mikeno, Virunga National Park, Democratic Republic of the Congo, August 2010.

Christophe Courteau / Road built along the path of the latest lava flow, leading towards Nyiragongo volcano silhouetted in the background, Virunga National Park, Democratic Republic of the Congo, August 2010.

Mark Carwardine / Mountain gorilla {Gorilla beringei} Virunga volcanoes, Zaire

Christophe Courteau / Man carrying goods on his head, walking along a path beside fields, with Sabyinyo Volcano in the background. The Virungas Volcanoes Mountains are home to Mountain Gorillas. Virunga Conservation Area,...

Christophe Courteau / Road leading to the Sabyinyo Volcano, Virungas Volcanoes Mountains, home of Mountain Gorillas. Virunga Conservation Area, Volcanoes National Park, Rwanda

Christophe Courteau / Road leading to the Virunga Conservation Area, home of Mountain Gorillas. In the background, Virunga Volcanoes (left Gahinga Volcano; right Muhabura Volcano). Volcanoes National Park, Ruhengeri Distr...

Andy Rouse / Mountain gorilla (Gorilla beringei) silverback walking in front of watching tourists, Virunga Volcanoes, Rwanda 2012

Andy Rouse / Cereal field in front of Sabinyo volcano, Virunga Volcanoes, Rwanda. The volcano is the habitat of the Mountain gorilla and crop fields are vital to the agriculture of Rwanda but they also reduce th...

Andy Rouse / Poachers snare in forest, left for wildlife but they can trap Mountain gorillas, Virunga Volcanoes, Rwanda, Central Africa

Andy Rouse / Poachers snare in forest, left for wildlife but they can trap Mountain gorillas, Virunga Volcanoes, Rwanda, Central Africa

Andy Rouse / Fishheye view of Bamboo forest habitat of Mountain gorilla, Virunga Volcanoes, Rwanda, Central Africa

Andy Rouse / Tourists trekking through rainforest habitat in search of Mountain gorillas, Virunga Volcanoes, Rwanda, Central Africa

Andy Rouse / Fisheye view of montane rainforest habitat of Mountain gorilla, Virunga Volcanoes NP, Rwanda, Central Africa

Andy Rouse / View of lake below Virunga Volcanoes NP, Rwanda, Africa, April 2010.

Andy Rouse / View of lake with island, below Virunga Volcanoes NP, Rwanda, Africa, April 2010.

Andy Rouse / A group of people gorilla trekking in misty forest. Virunga Volcanoes National Park, Rwanda, Africa, March.

Andy Rouse / Mountain gorilla (Gorilla Beringei) silverback, of Kwitonda group, Parc National des Volcans / Volcanoes NP, Virunga Mountains, Rwanda, Africa (non-ex)

Suzi Eszterhas / Mountain gorilla (Gorilla gorilla berengei) mother and infant, Virunga Volcanoes National Park, Rwanda

Suzi Eszterhas / Mountain gorilla (Gorilla gorilla berengei) mother feeding with infant, Virunga Volcanoes National Park, Rwanda

Suzi Eszterhas / Mountain gorilla (Gorilla gorilla berengei) infant sitting on mother's head feeding on thistle flower, Virunga Volcanoes National Park, Rwanda

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

Suzi Eszterhas / Mountain gorilla (Gorilla gorilla berengei) mother grooming infant (less than one month old) Virunga Volcanoes National Park, Rwanda

Suzi Eszterhas / Mountain gorilla (Gorilla gorilla berengei) mother grooming infant (less than one month old) Virunga Volcanoes National Park, Rwanda