PARENT SESSION
Oral Session # 29: Avian Ecology II.
Presiding: PS Warren
Tuesday, August 5. 1:30 PM to 5:00 PM, SITCC Meeting Room 103.

A comparison of avian frugivory and fruit ecology between a paleotropical and a neotropical site.

Choo, Johanna ^*,1, Stiles, Edmund¹, ¹ Rutgers, The State University of New Jersey, New Brunswick, New Jersey

ABSTRACT- We present a comparison of interactions among frugivorous birds and fleshy-fruited plants in two lowland rainforest sites with comparable climatic conditions. One site was located in the paleotropics of Sarawak (Mulu National Park), and the other in the neotropics of the Peruvian Amazon (Paucarillo Reserve). At each site, JC collected data for one year using systematic and comparable techniques. The comparisons we make are important because earlier pantropical comparisons of frugivory have been based on literature review. Conclusions drawn from analysis of literature alone may be confounded due differences in aims and methodologies of the studies. Our comparative study addressed this problem and allowed us to draw more rigorous conclusions based on quantitative and qualitative flora and avifaunal datasets. We assessed both understory and canopy avifauna frugivory, monitored phenology and estimated fruit crop sizes. Fruiting plants were identified and ripe fruit samples were collected. We found that Mulu had 40% fewer fruiting Families than Paucarillo and both locations had >20 fruiting Familes in common. In both locations, Moraceae was an important fruiting Family with many species, but Ficus was the only genus for Sarawakian Moraceae. Generally, fruit diversity was greater in Paucarillo, and we examined whether diversity was correlated with fruit production. Total avifaunal diversity was higher in Paucarillo (34% more species than Mulu), but both sites had similar diversity of frugivore species. Our study of both canopy and understory birds simultaneously showed that some species of frugivores foraged across the vertical forest strata, suggesting that their classification as understory or canopy frugivores could be misleading. In conclusion, we present the first quantitative and qualitative pantropical comparison of tropical fruit ecology and avian frugivory. Our findings would confirm and challenge some earlier conclusions drawn from comparative literature review, and will further our understanding of tropical bird-fruit interactions.

Key words: Fruit, Tropical, Frugivory, Birds