| This thesis describes a field-based comparison of fruit resources and avifauna in two lowland humid rainforest sites approximately equidistant from the equator, and located in the Neotropics (Paucarillo) and the Asian Paleotropics (Mulu). The purpose of this comparison is to utilized quantitative field data to support or refute conclusion derived from literature-based comparisons of Neotropical and Asian Paleotropical forests.; Phenological studies was conducted in Mulu during a non-mass flowering and fruiting year, and revealed that for 12 months there was low diversity and abundance of plants that flowered and fruited. In Paucarillo, there was only 2 months of fruit scarcity during the 12-month study period. Therefore, frugivores in both sites experienced resource bottlenecks at different time scales: Mulu- for a few years when the forest is not mass flowering and fruiting, and Paucarillo- for only a few months per year.; The seasonality of molting and breeding in birds from most tropical areas are due to environmental predictability of food supply and birds' ability of respond to onset of the wet season. The birds in Mulu and Paucarillo molt and breed in an area with predictable rainfall regimes. However, Mulu's birds do not breed during the height of the wet season because extremely high rainfall interfered with foraging and incubation of eggs.{09}In contrast, the breeding season of birds in Paucarillo was typical of tropical birds in other areas because peak rainfall in Paucarillo was as high as Mulu, so birds were able to breed and fully exploit the superabundance of food resources presented by the synergistic peaks in both insect and fruit abundance.; There were more canopy avian frugivore species in Mulu than Paucarillo. The higher local frugivore species richness in Mulu is due to higher proportion of opportunistic frugivores (a behavior arising from chronic shortage of fruits), higher mobility of canopy frugivores because of low local species richness and abundance of fruit resources, and a high species richness of figs which are highly attractive to fruit-eating birds. Mulu's frugivores were more flexible in their foraging behavior because there were more species that forage both in the understory and canopy compared to Paucarillo. |
