ROLE OF BIRDS ON THE REGENERATION OF THE WOODY BOSCIA-SENEGALENSIS (PERS.) LAM. IN SAHELIAN SAVANNA IN NORTH SENEGAL

In a sahelian savana, Boscia senegalensis (Pers.) Lam. has the best re generation level among ligneous species, specially under Acacia trees. Birds, but not mammals, eat many fruits of Boscia and, excepted when eating the pulp on the spot, are efficient dispersers either by fruit transportation in the bill or by swallowing the whole fruit. The seeds will be regurgitated or defecated later on after the pulp has been di gested, under cover of the trees where birds are roosting, of which 2/ 3 are Acacia trees. These deposition sites have already been enriched by birds' droppings. Controled germination tests of different sets of Boscia senegalensis seeds showed that passing through a bird digestive tract increases germination capacity and speed. Lamprotornis chalybae us is more efficient than any other observed bird species, since it ea ts many Boscia fruits through the whole fructification season, dispers es the seeds more away from parent trees and has the best results on i ncreasing germination capacity and speed and shortening germination de lay. Other important species regarding Boscia regeneration are Spreo p ulcher, Tockus erythrorhynchus and Colius macrourus.