FORAGING ECOLOGY OF 3 SYMPATRIC TURACOS IN A MONTANE FOREST IN RWANDA

We studied the foraging ecology of three sympatric turacos (Great Blue Turaco [Corythaeola cristata], Ruwenzori Turaco [Musophaga johnstoni] , and Black-billed Turaco [Tauraco schuettii]) in a tropical montane f orest in Rwanda between November 1991 and December 1992. All three spe cies fed primarily on fruit. Whereas Black-billed Turacos were strictl y frugivorous, Great Blue and Ruwenzori turacos were partially folivor ous;leaves constituted 25% and 6.3% of their overall diets, respective ly. The overall dietary diversity was highest for Great Blue Turacos a nd 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 Turacos mainly came from lianas and epiphytes. For the Ruwenzori and Black-billed turacos, the two te rritorial species, monthly dietary diversity increased with increasing fruit abundance in the environment, but this relationship did not hol d for Great Blue Turacos. During periods of fruit scarcity, all three species depended more heavily on their most frequently used foods; thi s trend was particularly evident in the two territorial species. Like most frugivores, these turacos probably were generalists that exploite d a great variety of fruit sources.