Raptors in West Africa’s savannas have strongly declined the past four decades and many species now survive only in a few pockets of intact habitat, mostly inside protected areas, while some... Show moreRaptors in West Africa’s savannas have strongly declined the past four decades and many species now survive only in a few pockets of intact habitat, mostly inside protected areas, while some species are on the brink of extinction. Little is known about the processes that sustain raptor populations within increasingly human-transformed savanna landscapes, and clues to the mechanisms and causal drivers behind population declines remain little studied. Moreover, it is unclear how changing conditions differently affect the diverse assemblage of Afrotropical and Palearctic raptors, which depend on the West Africa’s savannas for part or most of their life cycle, and how vulnerability, or adaptability to changing environments, relate to life-history traits such as their mobility, sex, age, body mass, and diet. This thesis quantifies the effects of land transformation on distribution, foraging, diet, and reproductive output of Palearctic and Afrotropical raptors, both migratory and sedentary, in West African savannas, to increase the knowledge that can support conservation efforts directed at the persistence of rich raptor populations in this part of the world. Show less
Since 1979, the hydrology of the Waza-Logone floodplain in semi-arid Cameroon has been affected by the construction upstream of a dam and embankment, reducing the flooding intensity in an area of... Show moreSince 1979, the hydrology of the Waza-Logone floodplain in semi-arid Cameroon has been affected by the construction upstream of a dam and embankment, reducing the flooding intensity in an area of 1500 km2, including Waza National Park. Subsequently, annual grasses invaded productive perennial grasslands, reducing the carrying capacity of the area for livestock, fisheries and wildlife. In 1994, after local consultations, a watercourse blocked by the embankment along the Logone river was re-opened, rehabilitating an area of 600 km2 of desiccated floodplain. Monitoring showed a gradual recovery of perennial grasslands, virtually completed in 2003, albeit with a species composition somewhat different from the 1970s. Numbers of most waterbirds increased two-fold, especially when their colonies benefited from local communities’ protection, whereas colonies of piscivorous birds were frequently destroyed. Floodplain antelopes showed an initial increase that has not persisted, probably because of increasing competition with livestock which densities increased three-fold due to the arrival of new pastoral groups and prolonged stay of herds traditionally frequenting the area. These developments indicate a problem in the sharing of the reflooding benefits between wildlife and people that rapidly respond to new opportunities, calling for intensified management planning to anticipate this unexpected success. A dialogue was institutionalised between protected area authorities and local communities. Effective conservation called for a stronger and lasting involvement of protected area personnel in planning and community conservation. Developed training courses showed good potential to upgrade knowledge and skills of present personnel. In addition, institutional changes are needed to assure the necessary increase in numbers of park personnel and their rotation, not only in and amongst national parks but with training institutes as well. The success of floodplain rehabilitation ultimately depends on long-term ecological and socio-economic monitoring, with individuals and institutions capable to translate upcoming insights into practice. Show less
