The effects of habitat change on the avifauna of Mount Marsabit forest, Kenya
Abstract
Forests are important ecosystems because of their immense contribution to national
economy and the livelihoods of local communities. They are also important for biodiversity
conservation and are indeed critical habitats for birds. In Kenya, native forests support 299 of
the country's 1079 species of birds. They also provide refuge to 50% of Kenya's 71
threatened bird species. The richness and composition of forest avifauna gives an indication
of the importance of the forest for bird conservation. Mount Marsabit ecosystem is a habitat
Island (as it is surrounded by desert-like conditions) facing increasing threat to its
biodiversity. Despite its protection status it is experiencing drastic human induced changes in
land cover both within the park and the surroundings. A steadily increasing population
coupled with sedentarisation around the reserve, growing livestock numbers and pumping of
water from the mountain to supply Marsabit town are some of the immediate concerns. For
proper management, there is need for efficient and effective monitoring. Birds can be used as
monitors of ecosystem change. Little quantitative work has been done on the avifauna of
Marsabit. The purpose of this study was to assess the structure and composition of the bird
communities and how they relate to habitat changes in Mount Marsabit National Park in
northern Kenya. The specific objectives were to determine (1) bird species composition,
abundance and diversity; (2) habitat utilization by major bird guilds and (3) the
vegetation/land cover changes and their effects on the avifauna in the study area. In this
study, a combination of standard bird sampling techniques, especially point counts (variable
radius circular plot), mist netting and ad hoc species searches were used to survey the
avifauna of Mount. Marsabit for six months along habitat gradients. Sampling was done on
three fixed transects. It was hypothesized that the distribution, abundance, and diversity of
birds on Mount. Marsabit followed altitudinal gradient and that the bird community changes
were linked to habitat loss and change. The study was carried out in seven different sites
between December 2004 and May 2005. The sites were selected along three large belt
transects traversing through major habitats and land use types adjacent to the park. The
results of the study indicated that the park is rich in bird habitats and hence bird species. A
total of 153 bird species belonging to 43 families were recorded. Most of the birds were
resident in the forest but there was clear movement of birds up and down the mountain slope
even on a daily basis. Typical dry land species moved up the mountain during the dry season
in search of food and water. Large fruit eating birds such as pigeons remained in the forest
throughout the study period. Bird densities varied significantly amongst mature forest,
degraded forest, open shrubland and farmland habitats. This study added 13 new species to
the list of birds known to occur in the area. The endangered William's Lark (Mirafa
Williamsi) and the vulnerable Lappet-faced Vulture (Torgos tracheolitos) and Imperial Eagle
(Aquila heliaca) were found in the park. In addition, 25 migratory species were recorded.
This study has shown that birds can be valuable indicators of the effects of upland forest
fragmentation on biodiversity. Protection of Mount Marsabit forest and the associated
wetlands is crucial to conservation of birds and biodiversity in general. The study was part of
a larger GEF sponsored initiative on the entire mount Marsabit ecosystem, it is hoped that the
findings will be useful in the formulation of a sound management plan for the area and form a
basis for future monitoring activities.
Citation
Master of Science degree in biology of conservationSponsorhip
University of NairobiPublisher
University of Nairobi School of Biological Sciences