August 12, 2011

The range of the Ethiopian Bush-crow in southern Ethiopia


Ethiopian Bush-Crow (Zavattariornis stresemanni)
In July 2010 we made a survey on the endemic Ethiopian Bush-crow Zavattariornis stresemanni in southern Ethiopia (Oromia Regional State, Borana zone). Along a 2,500 km-long track about 500 GPS-based records on birds and nest sites were collected. We counted a total of 2,600 birds or nests. Previous studies on the range of the Ethiopian Bush-crow were largely limited to countings along the paved roads and on random observations. With the data now available, it is possible to estimate the range of the species more reliably. We found birds or nests in 81 grids (5x5 minutes fields). This corresponds to an area of ​​approximately 7,000 sq. km. Thus, the range of the species is larger than thought. Previous estimates were 4,600 sq. km (BirdLife International species factsheed, July 2011). The results can be found in the following maps.

Map of the track and records
Distribution map (grid map, with a grid size of 5 minutes)
Map of the main breeding areas
Density map 

We are currently working on a model that explains the limited range of the species based on data on climate and vegetation. A publication is being prepared. I am grateful to Deutsche Ornithologen-Gesellschaft (DO-G) and Gesellschaft für Tropenornithologie (GTO) for funding.