Research

Ranomafana National Park (RNP)

RNP hosts 12 lemur species, and, as a tropical rainforest, has a high diversity of endemic plants and animals.  My most recent work at RNP was in collaboration with Chia Tan (CRES, San Diego Zoo) and Chris Vinyard (NEOUCOM).  We investigated resource partitioning among three sympatric bamboo lemur species (Hapalemur spp.) from the perspectives of feeding behavior, mechanical food properties, and a performance variable (bite force).  One of the fascinating aspects of Hapalemur feeding ecology is that they are all bamboo specialists that converge on the same species of giant bamboo, Cathariostachys madagascariensis, though they eat different parts.  We found that the mechanical properties of the food parts differed and that bite force was greatest in the largest species, Hapalemur (Prolemur) simus.   In addition to the data mentioned previously, we tested for the presence/absence of cyanide in the diets of the lemurs and in their urine and feces.  Cyanide was present in many, but not all, of the bamboo parts and in urine but not in feces. We also dissected the jaw musculature and gastrointestinal tracts of zoo specimens of H. griseus and H. simus.

      Photo: Chia Tan                                             Photo: Chia Tan

Hapalemur simus is the sole lemur predator of the culm (trunk) of the giant bamboo, which is the stiffest and hardest food eaten by any of the bamboo lemurs. 

Video stills of H. simus processing giant bamboo culm.

               Aftermath of H. simus bamboo feeding

We initially received funding from the Committee for Research and Exploration of the National Geographic Society in 2002-2003, and we continued on our project with funding from the National Science Foundation (BCS 0420133) from 2004-2007.