The Wembere river rises in hilly country at 06°S, south-east of Tabora and south-west of Singida. It forms the major river of the Eyasi internal drainage basin and flows north through the Wembere flood-plain before turning north-east at Lake Kitangire (TZ026) and thence into Lake Eyasi (TZ023). The Wembere flood-plain consists of open grassland intersected by drainage lines on the black cotton soil. Stands of Acacia seyal and Acacia drepanolobium grow around the edge of the plain, their exact distribution depending on the extent of waterlogging in the wet season. There are areas of Aeschynomene which die back during the dry season and produce dense stands after heavy rains.
See Box and Tables 2 and 3 for key species. The area is generally poorly known and only 177 species have been recorded from the area. The data here are mainly from fieldwork by Stronach in 1962. Apalis karamoja stronachi was discovered in 1962 at Ngongoro in the Wembere steppe. Its preferred habitat is Acacia drepanolobium woodland. Falco naumanni and Circus macrourus are likely to occur either on passage or may overwinter. Agapornis fischeri occurs in woodland along the fringe of the southern end of the flood-plain, one of only three concentrations of this species, and Histurgops ruficauda is locally frequent in woodland along the fringes of the flood-plain. Cosmopsarus unicolor probably also occurs and a fourth endemic, Francolinus rufopictus, may occur on the western fringes of the site. Interesting species recorded in the 1960s included Gorsachius leuconotus, Ardea goliath, Ardea purpurea, Ixobrychus sturmii, Ixobrychus minutus, Mesophoyx intermedia, Egretta ardesiaca and Plegadis falcinellus.
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
Over the last 35 years there has been extensive habitat destruction and alteration such that there are now far fewer trees and increased erosion. However, during periods of heavy rain the area becomes inhospitable to man and his livestock and this is when waterbirds breed. The exceptional rains in late 1961 caused excessive inundation and may well have concentrated the larger waterbirds in exceptional numbers at Chagana, subsequently reported by Stronach. During a ‘normal’ year the same number of birds may breed, but scattered more widely throughout the flood-plain. The Acacia drepanolobium woodland is threatened by overgrazing and repeated burning. There are no permanent settlements on the flood-plain and few large villages around the periphery.