Jozani biodiversity inventory report 2002 - Coastal Forests of Kenya ...

given the large number of visitors from all over the world going to Jozani each year. The
primates in Jozani would be the most susceptible to this problem.
10. Pollution
In Jozani area solid waste from litter is the main source of pollution. Materials like plastics,
cans, bottles, papers were often found scattered in many parts of the survey area. This is
mainly due to the increase in tourism activities. For the marine environment sewage from
coastal settlements and run-off from inland are potential threats. Inland run off water may
carry soil, pesticides, chemicals and other suspended materials into the sea. The potential
threat from pesticide misuse needs to be taken into consideration.
11. Motorway mortality
Despite its effect on wildlife, road kills of animals is often not documented (Lode, 2000).
Animal mortality is also reported to increase exponetially with increase in traffic volume. At
Jozani forest a number of animals including the Red colobus, are reported to be killed by
speeding vehicles (Struhsaker and Siex, 1998). Other affected species include blue monkeys,
antelopes, and occasionally birds, reptiles and amphibians. A suspended bridge constructed
for red colobus to cross the highway at Jozani is not used by the colobus. Improved designs
and new approaches may be necessary to reduce the road accidents. Road humps and sign
boards in areas frequently used by animals to cross have not proved to be very effective
either. Construction of underground passages and fauna ducts reduced mortality of crossing
animals in western France by 21% to 31% in places where road mortality reached 100%
(Lode, 2000).
12. Small population paradigm (Caughley, 1994)
Most of the plant and animal species and communities in Zanzibar are small and may also be
rare, endemic or near endemic. These populations are isolated from their congeners on the
mainland and hence may be subjected to inbreeding. The exception here could be the marine
organisms which are possibly not separated by any barriers from other populations and flying
creatures like bats and birds or pythons, hippos and crocodiles which are known to be able to
swim across the continental shelf between the mainland and Zanzibar (Moreau and
Pakenham, 1941). Island populations of plants and animals may appear healthy but could be
genetically poor. Woody vegetation communities with long generation time mostly tend to
exhibit this phenomenon whereby they physiognomically look healthy but are genetically
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