Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years crossing a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Republic

Andy Rouse / Mountain gorilla (Gorilla beringei) silverback in Susa group, Parc National des Volcans, Rwanda

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) silverback male portrait, Volcanoes NP, 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,...

Luis Quinta / Beach at the north of Principe Island, Democratic Republic of Sao Tome and Principe, Gulf of Guinea.

Christophe Courteau / Steam emerging from a fault on the summit of Nyiragongo Volcano, Democratic Republic of Congo. 2015.

Ingo Arndt / Looking up through the canopy of Eucalyptus plantation, Rwanda, Africa

Ingo Arndt / Rainforest slope Mount Bisoke (3711m), Mountain gorilla habitat (Gorilla gorilla beringei), Parc National des Volcans, Rwanda

Ingo Arndt / Mountain gorilla portrait (Gorilla gorilla berengeii) Parc des Volcans, Rwanda

Ingo Arndt / Mountain gorilla (Gorilla gorilla berengei) yawning, showing stained teeth, Parc des Volcans, Rwanda

Ingo Arndt / Clouds capping volcano crater, Parc des Volcans, Rwanda

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