Abstract # 98:

Scheduled for Thursday, August 9, 2001 10:45 AM-11:00 AM: Session 2 (University Hall 157) Oral Presentation

Diet and Feeding Differences Between Two Sympatric Indrids: Propithecus diadema diadema and Indri indri

J. Powzyk1,2 and C. Mowry3
1Wesleyan University, Dept. of Biology, Middletown, CT 06459, USA, 2Duke University, 3Berry College
     The feeding behaviors and dietary profiles of two indrids, Propithecus diadema diadema and Indri indri, were analyzed in a montane rain forest in Madagascar’s Mantadia National Park. Both lemur species are ceco-colic fermenting folivores. However, P. d. diadema ate a diverse mixture of fruits, seeds, flowers and leaves, while the bulk of I. indri’s diet consisted of immature leaves. This resulted in significantly higher levels of fat and water-soluble carbohydrates in foods eaten by P. d. diadema. Fiber values of items eaten were high (54% NDF) for both species, although not significantly different. Nevertheless, I. indri’s significantly longer feeding bouts on leaves suggest that its overall intake of fiber was greater than P. d. diadema’s. Levels of secondary compounds were high in certain food items, but overall were also not significantly different between the two indrids. P. d. diadema did, however, exhibit a strong preference for several alkaloid-containing seed species while none of the I. indri foods analyzed contained alkaloids. Furthermore, P. d. diadema 1) exhibited twice the number of geophagic episodes than I. indri, 2) had significantly shorter feeding bouts on all plant items, and 3) consumed a higher diversity of plant species. These behaviors may well control P. d. diadema’s intake of allelochemicals. Overall results of the study help to explain the coexistence of two closely related primate species.