WCS scientists recently completed the first-ever range-wide population census of the Zanzibar red colobus monkey (Piliocolobus kirkii). It is an endangered primate found only on the Zanzibar archipelago off the coast of East Africa.
According to the main findings of the survey, there are more than three times as many Zanzibar red colobus monkeys (more than 5,800 individual animals) than previously thought, and many more monkeys living within protected areas than outside of them.
Survivorship of young animals is very low, species now extinct in 4 areas, forest habitat on which the primates and others species depend are rapidly being cleared for agriculture and tourism development projects and hunting is common.
Some 69 percent of the population of Zanzibar red colobus monkeys live inside Unguja’s protected area network, and monkey groups found within protected areas boasted both higher average group sizes and more females per group.
Conversely, the assessment also highlighted challenges for conservation. Especially for the more than 30 percent of the monkey’s population that live outside of protected areas.
The scientists discovered that four of the forests previously known to contain Zanzibar red colobus monkeys no longer do. Four other locations were found to contain only one family group, which are unlikely to survive in isolation.
One of the largest threats to the Zanzibar red colobus monkey is deforestation. Forests on Zanzibar’s main island of Unguja are being lost at a rate of more than 19 square kilometers per year due to agricultural activities, residential development, and human population growth. The hunting of monkeys for food and retaliation for crop raiding is also a concern.