The Primates of Zanzibar

While one never gets tired of the majesty they see in the Mara, it can be nice to have a change of scenery. One of the amazing things about East Africa is that one does not need to travel far to experience a whole new ecological world. While the island of Unguja in the Zanzibar archipelago off the coast of Tanzania is a mere 3 hour flight from the Maasai Mara – it’s wildlife makes it seem a world away. Being an island, Unguja is home to many unique animal (and plant) species not found on the mainland. Perhaps some of the most unique species are found in Jozani Chwaka Bay National Park in the center of the island.

            The Jozani Chwaka Bay National Park is a 19 sq mile park on the island of Unguja and is the only national park in Zanzibar. It’s also one of the last strongholds for the endangered Zanzibar Red Colobus monkey. Between 1,600 and 3,000 individuals survive, and despite having Jozani as a stronghold, approximately 50% of the population lives outside of protected areas. The species is also found on Uzi and Vundwe islands in the archipelago. The main threat to these monkeys is habitat loss, but they are also sold in the exotic pet trade and are hunted for their meat.

A mother Zanzibar Red Colobus monkey and her infant. The Jozani primates are very habituated to humans and she continued to nurse her infant despite our presence. 

It’s thought that the monkey has been isolated on the island since the end of the Pleistocene, making it unique from other colobus species found on the mainland. The monkeys’ coloration ranges from dark red to black with a pale underside. While the monkey has a long tail much like that of New World primates, the tail of the Zanzibar Red Colobus is not prehensile and is instead used only for balance. Unlike other primates, the Zanzibar Red Colobus monkeys lack an opposable thumb. To make up for this lack of a digit they have four long fingers on each hand that allow them to clasp firmly to branches as they travel through the forest.  

Another Red Colobus mother and infant. The Zanzibar Red Colobus monkeys are known for their smaller head and hunched body shape - both exhibited well here. 

 The monkey is primarily arboreal and tend to feed on fresh young leaves and are one of the only monkey species to not feed on ripe fruit. However, in agricultural areas the monkeys have been known to spend more time on the ground. Certain populations of red colobus monkeys have been observed feeding on charcoal, which has been shown to be passed on from mother to offspring and may aid in the digestion of exotic plants.

Juvenile Zanzibar Red Colobus playing in the canopy. 

            In addition to Zanzibar Red Colubus, Syke’s monkeys are also found within the national park. While not endangered or vulnerable, the survival of the Syke’s monkey is threatened by habitat destruction and are susceptible to human retaliation due to their tendency to feed on crops or exotic trees. Unlike the Zanzibar Red Colobus, the diet of these monkeys consists mainly of fruits. They have also been observed consuming invertebrates such as slugs and worms. Unlike the Red Colobus Syke’s monkeys exhibit sexual dimorphism with the males being larger than the females.

A Syke's monkey munching on some old leaves and fruit. 

              Being able to walk in the forest and see some of its most charismatic species was definitely one of the most memorable parts of the holiday. Jozani Chwaka Bay National Park was and continues to be a stronghold for both species of primate as well as tree hyrax, bush-baby, dik-dik, and a wide variety of marine species. The park currently partners with the local people in efforts to raise awareness about the forest and its inhabitants to work towards its current and future conservation.