Greater Mahale Ecosystem

The Greater Mahale Ecosystem comprises the Mahale Mountains National Park in western Tanzania and the surrounding natural habitat. Together with the Gombe National Park to the north and the Southern Tanganyika region to the south these areas contain all of Tanzania’s chimpanzees (other than those introduced to Rubondo Island). In the Greater Mahale Ecosystem only 11% of the natural habitat is protected and this is in the Mahale Mountains National Park together with the Tongwe East Forest Reserve.  Species of conservation concern in this landscape include the eastern chimpanzee which occurs in some of the driest habitat anywhere throughout its distribution, red colobus, elephant, lion, sable, Kungwe apalis – an endemic bird that is only found here, and several plant species only found here also, particularly in the Sitebi highlands.

The total number of mammal, bird, reptile, amphibian and plant species recorded from this landscape to date number 1,939, of which 15 species are endemic to the Albertine Rift and 28 species are threatened (CR, EN, VU) under the IUCN Redlist (2010).

Conservation Challenges

This part of the Albertine Rift has much lower human population densities compared with further north. However, the settlement of refugees from the wars in Burundi and Democratic Republic of Congo (DRC) in the landscape has led to loss of habitat and settlement in the region by Tanzanian nationals also. Illegal logging for timber in forests outside protected areas and increasing fire is likely to lead to forest loss and degradation over time. People settling in the area tend to locate themselves near natural forest as these tend to be near water sources and have fertile soil. As a result small riverine strips of forest, critical for chimpanzees and the endemic Kungwe apalis, are disappearing.

Conservation Approach

The WCS Southern Highlands Program manages conservation of Southern Tanganyika region and is working to conserve the  remaining forest and connecting corridors in this landscape where the most southerly population of chimpanzees occur in Africa. The WCS Albertine Rift Program undertook surveys of the Greater Mahale Ecosystem in the mid 2000s with Jane Goodall Institute (JGI), to estimate chimpanzee numbers for the area as well as assess the other diversity of the landscape. The results were used in developing a ten year conservation plan (report 1, 2, 3) for the Greater Mahale Ecosystem led by JGI and Frankfurt Zoological Society together with TANAPA and TAWIRI (Tanzania Wildlife Research Institute). They were used in a project managed by Frankfurt Zoological Society (FZS) to start to develop conservation activities in the broader landscape. JGI  led the process to develop a conservation action plan for chimpanzees (12 MB) in Tanzania which built on the data collected during these surveys also. Since the surveys JGI have started a program in the Masito-Ugalla region in the northern sector of the Greater Mahale Ecosystem but to date there are critical needs for conservation activities in the Sitebi highlands region east of Mahale Mountains National Park where most of the endemic plants and the Kungwe apalis are found. WCS is still active in the Southern Tanganyika region but at present has no activities in the Greater Mahale Ecosystem.