| I documented 82 species of sympatric terrestrial mammals, 2 aquatic mammals, and 31 bats for San Pedro, a rainforest location in northeastern Peru. Catchment area was approximately 125 km2. The inventory was prepared with data from small mammal trapping, skull collections of local hunters, transect censuses, and reports by other researchers. Included were 30 rodent species, 17 obtained through removal trapping in 1994 trough 1999.; From May 1997 to December 1998, pregnancy rate of spiny rats ( Proechimys spp.) followed the fluctuations of fruit fall with a 2-month time lag (r = 0.82, P = 0.007). In terra firme biomass of the terrestrial small rodent community averaged 51 to 143 kg/km2. In varzea, the seasonally flooded forests of white-water rivers, average biomass decreased from 389 kg/km2 in 1995 to 175 kg/km2 in 1997. In some habitats individual species had different long-term population dynamics.; Multivariate analysis of trapping results yielded six terrestrial small rodent communities. In varzea one community occupied all habitats. In terra firme each of the five communities occupied one or more different habitats. The varzea community had higher biomass and densities, but was less diverse than terra firme communities.; The five Proechimys species collectively dominated all communities (>90% of the captures). Each species showed distinct habitat preferences, thus reducing potential interspecific competition. The large P. quadruplicatus (mean weight = 358 g) dominated the seasonal and productive varzea. The small P. kulinae (mean weight = 165 g) dominated most habitats of dense, primary terra firme forests. The midsize species, P. cuvieri, P. simonsi, and P. brevicauda (mean weight 282 to 300 g) were found in terra firme habitats with broken canopies, including streambeds and human altered habitats. Sympatry of three or more Proechimys species only occurred in these habitats. Results suggest that seasonality of the environment favors large litter species, perhaps because they can take advantage of production peaks. Unproductive habitats favor small species, perhaps because of reduced energy requirements.; The rodent community includes two to three abundant species and many rare species. Thus, as most Western Amazonian sites, San Pedro is species rich because it has more rare species than sites elsewhere. |
