Chumbe Island

Approximately 90% of Chumbe Island is covered by one of the last remaining pristine 'coral rag' forests in Zanzibar. The Government of Zanzibar declared it a closed forest in 1994, and the management was entrusted to Chumbe Island Coral Park Ltd. (CHICOP).

Baseline surveys conducted in 1994 and 1995 on the Chumbe forest have provided a rich database for the management of the forest and the development of nature trails. Several forest trails were cut in the southern part of the island, leaving the tree canopy intact. Vegetation of special interest was noted (such as Uvariodendron kirkii, previously thought to be extinct in this region) and monitoring plots were established.

In the following text you will find information about this specialized forest habitat and some of its occupants, namely the rare Coconut Crab and the endangered Ader's Duiker.

View from Lighthouse

Chumbe hosts a highly specialised plant community that has developed to survive without any groundwater, instead depending on capturing the moisture from the humid air and storing the rainfall during the rainy seasons. The bedrock of the island is made up of an impressive substrate of fossilized coral. You can still see the skeletal structures of corals and giant clams - a gentle reminder of the passage of time. More staggering still is the coral-rag forest. The density of the forest is spectacular, as adventitious roots thrust out in all directions and epiphytic species cling to life by wrapping themselves around all available surfaces. Researchers have taken up to four hours to transverse the 1 km stretch through the central forest reserve and the crags and caves hidden underfoot as remnant of the reef structure of this fossilized coral habitat, makes studying this environment both challenging and consistently rewarding as new discoveries are constantly uncovered. For guests the nature trails provided allow for an insight into this otherwise virtually impenetrable habitat.

In the management of this habitat, materials imported onto the island are carefully screened to avoid any non-indigenous elements intruding into this spectacularly preserved environment. Such practice was unfortunately not in place in the early 1900's when rats were accidentally introduced onto the island (probably by the British ships bringing materials when the lighthouse was established). However, after the successful conclusion of the rat eradication campaign in May 1997, managed by CHICOP with support from specialists from Cork University in Ireland and the Zanzibari Plant Protection Division, the island was freed from this non-indigenous species and the island's flora (that had been under pressure from competition from the rats consuming the vital regenerating fruiting bodies) improved conditions further for the sanctuary.

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Coconut Crab

The rare Robber or Coconut Crab (Birgus latro) - the largest land crab on earth - is common on Chumbe Island while it is threatened elsewhere in the Indian Ocean as it is widely eaten and used in fish traps. With a carapace diameter of up to 45 cm they can climb up to the top of coconut trees and easily crack coconuts with their powerful claws. These crabs have evolved to live on land but begin their life in the sea, later adopting shells as houses for protection until they grow large enough to manage with just their hardened carapace alone. This gives these crabs a lobster-like appearance with their curled-under abdomens. Research into this species in the East African region is extremely limited and this disappearing species is unfortunately still listed as data deficient in the IUCN endangered species listing as simply nobody knows how many are left! But fishermen report decreasing sightings and Chumbe hopes to assist this plight in the establishment of a study base for comparing Chumbe's healthy population with neighbouring findings, so that at last this species may gain international support in its protection.

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Ader`s Duiker

The Ader's Duiker (Cephalophus adersi) is an endangered species accepted to be extinct in its original range on the African mainland coastal thicket and forests of the Kenyan coast. Today, only a relict population survives on Zanzibar (Unguja) island and this small population continues to dwindle as a result of habitat destruction and uncontrolled hunting despite being protected by Zanzibar law (Archer 1994). A long-term captive breeding program is now proposed by the Department of Forestry of Zanzibar, but urgent attention is required if this species is to avoid extinction.

Therefore, in 1995 CHICOP began work with the Department of Forestry towards the establishment of an Ader’s duiker sanctuary in the Chumbe forest. Consultants of the Department and of CHICOP studied conditions there, and the Chumbe forest was found to be of exceptionally good quality to provide suitable habitat for these duikers (D. Aplin; A. Williams).

Therefore, in December 1997 the first duiker was translocated to Chumbe, as a pilot test, and in February 2000, following much preparation throughout the International Conservation Community, and with assistance from international experts, five more individuals were brought to the island. Following the principles of re-introductions of endangered species, as outlined by IUCN, monitoring procedures are in place using remote camera sensors located in key areas in the forest, where they monitor the animals behaviour, territory and feeding patterns (J. MacPherson & D. MacPherson).

This Project is managed in collaboration between Chumbe Island Coral Park (CHICOP) and The Wildlife Division of The Department of Commercial Crops, Fruits and Forestry (formally the Commission for Natural Resources) within the Ministry of Agriculture, Natural Resources, Environment and Co-operatives of Zanzibar. Munich-Hellabrunn Zoo and the Mammal Ecology Research Group (MERG), Royal Holloway University, London provided technical support. The Project was financed and supported by Chumbe Island Coral Park Ltd. (CHICOP), Chicago Zoological Society (CZS), Eco-tec (Zanzibar) Ltd., World Wide Fund for Nature (WWF), Fauna and Flora International (FFI), British Ecological Society (BES), British Airways, Munich-Hellabrunn Zoo, and Bavarian Television.

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