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| The Basra reed warbler (Acrocephalus griseldis) and the cinereous
bunting (Emberiza cineracea) are the only two Western Palearctic
passerine bird species that overwinter in East Africa and are
classified by BirdLife International as endangered and near-threatened,
respectively. To refine the African wintering ranges of these two
species, we made an effort to collect as much distributional data as
possible. We then used the available point-locality data to predict the
wintering distributions using a Geographic Information Systems (GIS)
based inductive modelling technique called BIOCLIM. For this purpose,
we developed four environmental GIS layers that are presumed to reflect
the environmental preferences of migrant birds. Our data showed that
the known winter distribution of the Basra reed warbler was
concentrated in Kenya, Tanzania, Malawi and Mozambique, where it was
usually found in dense vegetation growing in coastal scrub, woodland
thickets, swamps, marshes, flooded pools and grasslands, and along
ditches and edges of rivers, ponds, lagoons and lakes. The predicted
winter distribution of this species includes most of East Africa but,
given the habitat preferences of this species, is probably limited to
low-lying areas near the coastline. The known winter distribution of
the cinereous bunting is so far limited to Eritrea, where the species
has been observed in October, November, February and March, in sparsely
vegetated, sandy or rocky habitats on coastal plains and deserts. The
predicted winter distribution of this species includes the plains and
hills along the Red Sea coasts in southern Egypt, Sudan, Eritrea,
Ethiopia and Sudan, as well as a few inland areas in Sudan, Ethiopia
and Kenya. | |
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