Results

Fourteen species of Primates have been confirmed to occur sympatrically in the Reserva Comunal Tamshiyacu-Tahuayo (Table 1). These include 3 species of Callitrichids and 11 species of Cebids. Another Cebid, Aotus nigriceps, is believed to occur in the reserve, but has only been reported from vocalizations. Congeneric Primates inhabiting the reserve include Saguinus fuscicollis and S. mystax, Cebus apella and C. albifrons, and Saimiri boliviensis and S. sciureus. The large-bodied Primates of the area include two pitheciine Primates, Cacajao calvus and Pithecia monachus, the woolly monkey, Lagothrix lagothricha, the black spider monkey, Ateles paniscus, and the red howler monkey, Alouatta seniculus. The night monkey, Aotus nancymae and the pygmy marmoset, Cebuella pygmaea also occur within the reserve.

Hunting by ribereños has decreased the densities and biomasses of the large-bodied Cebids in the reserve, especially in the persistently hunted Tahuayo-Blanco region (Table 2). The biomass of Cebids in the Yavarí Miri region was estimated at 420 kg km -2 which is more than double that of the Tahuayo-Blanco region of 157 kg km -2 .

Ribereños hunted 323 Cebids in Tahuayo-Blanco between October 1990 and October 1991 (Table 3). This harvest resulted in the extraction of 1410 kg of Primate biomass.

The biomass of Callitrichids in Yavarí Miri was 20 kg km -2 which was similar to the biomass of Callitrichids in Tahuayo-Blanco of 21 kg km -2 . This similarity in the populations of Callitrichids suggest that the forests of the Yavarí Miri and Tahuayo-Blanco are similar and the differences in Cebid biomass might indeed be a result of previous hunting pressure.

Callitrichids were rarely hunted, because of their small body size. Indeed, ribereños of Tahuayo-Blanco only hunted 12 Callitrichids between October 1990 and October 1991.

Table 1. Primate species of the Reserva Comunal Tamshiyacu-Tahuayo, northeastern Peru.

Table 2. Average body weights, densities of individuals and biomasses of Primates in two study areas of the Reserva Comunal Tamshiyacu-Tahuayo

Biomasses of species were calculated by multiplying the density of individuals by the average body weight of the species. Average body weights were determined from hunted and live captured animals.

Table 3. Hunting pressure and Primate biomass extracted from Tahuayo-Blanco between October 1990-October 1991