Mgambo Forest Reserve: A biodiversity survey. - Eastern Arc ...

Mgambo Forest Reserve
Table 2 Forest area in the East Usambara Mountains
(based on Johansson and Sandy, 1996).
Forest type Area % of area
Lowland forest 29497.4 62.9
Submontane forest 12916.6 30.6
Forest plantation 2723.6 6.5
TOTAL 45137.6
The mammals of the East Usambara Mountains show limited endemism (Kingdon and Howell
1993). However, there are several species of special interest. These include: the restricted Zanj
elephant shrew, Rhynchocyon petersi, which is common in the Usambara Mountains (Collar and
Stuart, 1987) yet listed as globally ‘Endangered’ by IUCN due to a decline in habitat extent and
quality; Eastern tree hyrax, Dendrohyrax validus, listed as ‘Vulnerable’ by IUCN (Hilton-Taylor,
2000), and the Lesser pouched rat, Beamys hindei which is also considered ‘Vulnerable’ by IUCN
(Hilton-Taylor, 2000).
There are at least 11 species of reptiles and amphibians endemic to the East and West Usambara
Mountains (Howell, 1993). The East Usambara Biodiversity Surveys provide further information
on new species and species’ range extensions. A new species of snake, Prosymna semifasciata,
was recently found in Kwamgumi and Segoma Forest Reserves (Broadley, 1995) and a recently
described amphibian species; Stephopaedes usambarae (Poynton and Clarke, 1999) has been
recorded by the surveys in Mtai and Kwamgumi Forest Reserves.
The forest avifauna of the East Usambara Mountains has a high diversity with at least 110 species
(Stuart, 1989). Six species occurring in the lowland forests are considered ‘Vulnerable’ to global
extinction: Sokoke scops owl, Otus ireneae; the endemic Usambara eagle owl, Bubo vosseleri;
Swynnerton’s robin, Swynnertonia swynnertoni; East coast akalat, Sheppardia gunningi; Amani
sunbird, Anthreptes pallidigaster and the Banded green sunbird, Anthreptes rubritorques (IUCN,
1996).
The East Usambara Mountains are essentially forest ‘islands’ (Lovett, 1989). There has been
natural forest in the area for several million years. The Usambara Mountains harbour many
species that have been geographically separated from their closest relatives for long periods. They
also serve as a refuge for formerly widespread flora and fauna that have become extinct over
much of their former area (Iversen, 1991a).
These forests have been under continuous exploitative human pressure for at least 2,000 years
(Schmidt, 1989). Until recently, especially before the past 50 years, (Kikula, 1989), this pressure
was sustainable. However, the growing human population in the area is leading to increased
pressure on the remaining natural forest, and represents the main threat to their survival.
East Usambara Conservation Area Management Programme Technical Paper 59
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