Differential patterns in flower feeding by Eulemur fulvus rufus and Eulemur rubriventer in Madagascar.

In this paper, I describe the differential patterns of flower feeding observed in rufous lemurs (Eulemur fulvus rufus) and red-bellied lemurs (E. rubriventer) in the Ranomafana National Park, Madagascar. Red-bellied lemurs licked nectar from flowers while rufous lemurs ate all flower parts from the same flower species. Several hypotheses are examined to explain the significance of flower feeding in these two species. In many primate species, flower feeding functions as a keystone resource and/or primates act as pollinators while feeding on flowers. Although peak flower feeding occurred during a decline in food availability, fruit was always (the preferred food item so that flowers did not function as a keystone resource. Second, red-bellied lemurs appear to be potentially better pollinators compared to the rufous lemurs because 1) they left flower reproductive parts intact while feeding, 2) they visited more than one tree or liana of the same plant species in the same day, 3) pollen was observed on the faces of individuals as they traveled from plant to plant, and 4) they have a feathered, brush-like tip on their tongue which rufous lemurs lack. Finally, the difference in flower feeding styles between the lemur species also affected three aspects of diet: 1) feeding bout duration, 2) the size of feeding subgroups, and 3) return visits to flowering sources. These subtle differences in diet within food categories can allow these two otherwise similar lemur species to coexist. © 1992 Wiley-Liss, Inc.