Population and feeding ecology of the Marabou stork (Leptoptilos crumeniferus) around Lake Ziway, Ethiopia

Abstract

A study was carried out around Lake Ziway, covering both dry and wet seasons in 2010, to investigate the population structure, habitat association and feeding ecology of the Marabou stork (Leptoptilos crumeniferus). Sample sites were designed based on the vegetation type and area cover. Line transects and point counts counting methods were used on the randomly selected sampling sites. Focal sampling method was also employed for observation of feeding. Face-to-face standard questionnaire interview and direct observation techniques were also conducted. A total of 318 and 594 Marabou storks were counted during dry and wet seasons, respectively. The number of birds during the dry and wet seasons was significantly different (p<0.05). Lake shore was highly preferred for feeding. They were observed to feed on food items such as fish scraps (41%), carrions (23%), frogs (16%), worms (12%) and insects (9%), with variations from season to season. Their breeding nests were mostly in the town and on Acacia tortilis and Acacia nilotica trees. On average, 2.1 immature/young individuals were observed per nest. Habitat degradation in connection with agricultural activities of floriculture and urban expansion are the main threats to the survival of the Marabou stork and other wetland birds of the present study area.

Key words/phrases: Acacia, Marabou stork, Water birds, Ziway.