Bernard Castelein / Zanzibar Red Colobus (Procolobus kirkii) jumping through the air, Jozani Chwaka Bay NP, Zanzibar, Tanzania

Bernard Castelein / Zanzibar Red Colobus (Procolobus kirkii) relaxing on tree branch, Jozani Chwaka Bay NP, Zanzibar, Tanzania

Bernard Castelein / Zanzibar Red Colobus (Procolobus kirkii) juvenile, sitting in tree calling, Jozani Chwaka Bay NP, Zanzibar, Tanzania

Bernard Castelein / Zanzibar Red Colobus (Procolobus kirkii) mother with offspring, sitting in tree, Jozani Chwaka Bay NP, Zanzibar, Tanzania

Bernard Castelein / Zanzibar Red Colobus (Procolobus kirkii) head portrait of infact, sitting with mother, Jozani Chwaka Bay NP, Zanzibar, Tanzania

Pete Oxford / Kirk's red colobus (Procolobus kirkii) Jozani Forest Reserve, Zanzibar, Tanzania

Pete Oxford / Kirk's red colobus (Procolobus kirkii) in tree feeding, Jozani Forest Reserve, Zanzibar, Tanzania

Anup Shah / Zanzibar red colobus monkey (Procolobus kirkii) mother with young, Zanzibar, Tanzania, East Africa

Anup Shah / Zanzibar red colobus portrait (Procolobus kirkii) Jozani forest, Zanzibar, Tanzania

Anup Shah / Zanzibar red colobus monkey (Procolobus kirkii) sheltering under leaf, Jozani forest, Zanzibar, Tanzania

Anup Shah / Zanzibar red colobus monkey (Procolobus kirkii) with young, Jozani forest, Zanzibar, Tanzania

Martin Grimm/ BIA / Zanzibar Red Colobus (Procolobus kirkii) calling, Jozani Chwaka Bay National Park, Zanzibar, Tanzania