Effects on Birds of the Conversion of Savannah to Farmland in the Sahel: Habitats are Lost, But Not Everywhere and Not For All Species

Many migratory bird species, several of which are in severe decline, and African residents spend the northern winter Sahel, by nature a huge savannah, half has been converted into farmland. We analyse impact such large-scale changes on birds. On average, woody cover is 38% lower farmland than savannah. More critically, farmers have drastically changed vegetation communities their In arid semi-arid zone, they partly removed bird-rich trees as Umbrella Thorn Acacia tortilis Desert Date Balanites aegyptiaca, yet further south created richer habitat replacing original species Winter Faidherbia albida, preferred tree for Afro-Palearctic migrants (but less so Afro-tropical residents). Still south, two bird-poor trees, Shea Tree Vitellaria paradoxa Locust Bean Parkia biglobosa, dominate farmland, causing birds, mainly residents, to lose habitat. As consequence farming, arboreal confronted with degradation zone southern humid but face more favourable wintering conditions sub-humid central zone. Ground-foraging birds abundant savannah farmland; 24 from this group, including three wheatear many twice Conversion mixed outcomes ground-foraging were generally negative except five (including Western Yellow Wagtail Motacilla flava) Thus, conversion represents loss not all species.