The Rubeho mountains form a dissected plateau in the centre of the Eastern Arc mountains where the mountain chain skirts the western edge of Mikumi National Park (TZ006) and the Mkata plain. To the north, across the valley of the Mkondoa river, lie the Kiboriani and Ukaguru mountains (TZ067), while to the south, beyond the Ruaha river, are the Udzungwa mountains (TZ066). Only three Forest Reserves are listed for these mountains and are included in the IBA: Ukwiva (54,635 ha), Mafwemiro (3,238 ha) and Mangalisa (4,988 ha). Ukwiva covers the main highland block and rises from the Myombo river valley at 1,000 m to Ledengombe peak at 1,941 m. The western part of the reserve comprises dry montane forest at 1,600–1,700 m with a low canopy of 10–15 m, dominated by Macaranga kilimandscharica in the valleys. However, the eastern edge of the reserve is much more humid and undisturbed, except by elephants Loxodonta africana. Mafwemiro sits across the southern arm of the north-western plateau which rises to 2,152 m. Mangalisa covers the top plateau of an isolated mountain block in the Great Ruaha river basin, lies 15 km west of the main plateau and rises to 2,286 m. Its vegetation comprises semi-evergreen woodland patches and rather disturbed forest in the northern part and mature Podocarpus-dominated forest in the southern part.
See Box and Tables 2 and 3 for key species. Both Zoothera gurneyi, a nominally montane species, and Cossypha natalensis, a low-altitude species, have been reported breeding at one locality. The river holds Anas sparsa and Podica senegalensis. Macrosphenus kretschmeri has been recorded at 1,800 m, 300 m higher than previously recorded. Gorsachius leuconotus has been recorded in the valley near Madazini. In Mangalisa Sarothrura elegans, Schoutedenapus myoptilus, Apaloderma vittatum, Lanius marwitzi and Muscicapa caerulescens all occur. Both Nectarinia mediocris and Nectarinia moreaui were noted and Monticola angolensis occurred in the woodland on the northern part of the plateau at lower elevations. Sheppardia lowei has not been recorded, but may exist at low densities.
Non-bird biodiversity: Among mammals, Loxodonta africana (EN) and Syncerus caffer (LR/cd) use Ukwiva Forest Reserve and at least some of these animals may move on an annual basis between these forests and Mikumi NP; Cephalophus natalensis (LR/cd) occurs on Mangalisa.
Pressure/threats to key biodiversity
There is less pressure on these forests than many others in the Eastern Arc because of difficulties of access. However, surrounding populations are increasing and there are problems of cultivation within the Forest Reserve in a few areas.