Floodplain rehabilitation in Far North Cameroon: expected impact on bird life

Abstract

Scholte, P., de Kort, S. & van Weerd, M. 2000. Floodplain rehabilitation in Far North Cameroon: expected impact on bird life. Ostrich 7 (1): 112–117. The Logone floodplain in the sahelo-Sudanian zone of Cameroon used to be a highly productive ecosystem. Perennial pastures and fish played a crucial role for fishermen, pastoralists and wildlife. The construction of an upstream dam reduced inundation causing widespread degradation Nonetheless, approximately 350 bird species have still been observed. They include eleven waterfowl species which surpass the IWRB/Ramsar criterion one % of West African population). The few available surveys suggest that prior to the dam construction, the area harbored an even more abundant birdlife. Presently possibilities exist to release excess water for floodplain rehabilitation. In 1994, a pilot release has been executed to verify predicted advantages for men and wildlife. Larger scale rehabilitation of the Logone floodplain is formulated, based on the pilot release results. Annual total waterfowl, as well as heron colony counts have been executed showing an increase in bird numbers. Data variability questions somewhat the conclusion that this has been exclusively due to increased flooding. Additionally, bird populations of degraded annual grasslands and well flooded perennial grasslands have been assessed by line transacts. Results showed the much higher numbers of waterfowl and passerines in perennial grassland. Hydrological and vegetation monitoring showed a change of annual into perennial grassland due to the re-flooding, which might lead to increased bird populations. Questions remain how to extrapolate these findings to the entire area to be re-flooded, justifying continuous counting and studying factors limiting bird populations. Such a study started for the Black Crowned Crane, a resident flagship species. For migratory species, surveys are recommended to assess the role of other wetlands in the Lake Chad basin.