Habitat preferences and status of an elusive forest species: the Oberlander's Ground-Thrush Zoothera oberlaenderi in Uganda

For a large number of threatened bird species, no information on habitat requirements or population estimates are available. We show for one of the least-studied African birds, the Oberlander's Ground-Thrush Zoothera oberlaenderi, how a first assessment of its habitat preferences and population size can be done if a short-term census is combined with a GIS-based species-habitat analysis. Between 9 February and 14 March 2008, we made intensive field surveys, using point counts and mist-netting in Semliki and Bwindi Impenetrable National Parks (BINP), two forests in Uganda from which there are previous records. While the species was not recorded in Semliki, eight were heard singing in BINP. We made the first analysis of this species' habitat preferences by analysing all records of the species with variables extracted from GIS layers for the BINP. It preferred dense forest types, close to rivers and at elevations of 1 500-1 935 m. Using detailed habitat information we calculated 30 km2 of suitable habitat (out of the 331 km2 in BINP), which could hold an estimated minimum of 36-45 males. Because there is on-going forest degradation and deforestation within its potential distributional range in Uganda and the Democratic Republic of the Congo, and because the population in Uganda appears so small, there is a need to reconsider the IUCN Red List category of the Oberlander's Ground-Thrush, which is currently Near Threatened.