A Preliminary Analysis of a Neotropical Mammal Fauna

Abstract

The abundance and biomass of species of nonvolant mammals on Barro Colorado Island are estimated and compared with data from other areas. The edentates, particularly the sloths, are shown to be dominant elements in neotropical forests. The sloths and howler monkeys together constitute more than 50 percent of the biomass of mammals, emphasizing the importance of the forest canopy. The bulk of the mammalian biomass is maintained by species which are browsers or frugivores and browsers. The total energy consumption of each species is estimated and the metabolic rate of the whole mammalian fauna is judged to be between 3000 and 4000 kilocalories per hectare per day on Barro Colorado Island. THE OBJECTIVE of this paper is to assess the biomass and the numbers of different mammalian species in a defined area of neotropical forest. For almost a decade we have been concerned with this assessment and with defining the trophic structure of the major species of nonvolant terrestrial mammals within a neotropical rainforest ecosystem. It is most important to determine the biomass and the trophic role of each major species for the following