Foraging ecology of three sympatric turacos in a montane forest in Rwanda

Abstract

We studied the foraging ecology of three sympatric turacos (Great Blue Turaco [Corythaeola cristata], Ruwenzori Turaco [Musophaga johnstoni], and Black-billed Turaco [Tauraco schuetti]) in a tropical montane forest in Rwanda between November 1991 and December 1992. All three species fed primarily on fruit, Whereas Black-billed Turacos were strictly frugivorous, Great Blue and Ruwenzori turacos were partially folivorous; leaves constituted 25% and 6.3% of their overall diets, respectively. The overall dietary diversity was highest for Great Blue Turacos and lowest for Black-billed Turacos. Most fruits eaten by turacos came from trees. Although most leaves eaten by Great Blue Turacos also came from trees, leaves eaten by Ruwenzori Tufacos mainly came from lianas and epiphytes. For the Ruwenzori and Black-billed turacos, the two territorial species, monthly dietary diversity increased with increasing fruit abundance in the environment, but this relationship did not hold for Great Blue Turacos. During periods of fruit scarcity, all three species depended more heavily on their most frequently used foods; this trend was particularly evident in the two territorial species. Like most frugivores, these turacos probably were generalists that exploited a great variety of fruit sources.