Cyril Ruoso / Pygmy kingfisher (Ceyx picta) portrait, Cross River State, Nigeria. Non-ex

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male, Pandillus Sanctuary, Nigeria. Non-ex

Cyril Ruoso / Chimpanzee (Pan troglodytes) baby playing with keeper, Pandrillus Drill Sanctuary, Nigeria

Cyril Ruoso / Chimpanzee (Pan troglodytes) adults and young, Pandrillus Drill Sanctuary, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) alpha male calling, Pandrillus Drill Sanctuary, Cross River State, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male, Pandrillus Drill Sanctuary, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult female grooming alpha male, Pandrillus Drill Sanctuary, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male close-up of face, Pandrillus Drill Sanctuary, Nigeria

Cyril Ruoso / Drill (Mandrillus leucophaeus) adult male appeasement face, Pandrillus Drill Sanctuary, Nigeria

Ernie Janes / White-throated guenon (Cercopithecus erythrogaster) captive, occurs in Nigeria and Benin. Foliage digitally added.

Ingo Arndt / Four horned chameleon male {Chamaeleo quadricornis} Nigeria

Thomas Marent / Chimpanzee (Pan troglodytes) sub-adult, Afi Mountain Wildlife Sanctuary, Nigeria