Nesting Behavior of Lowland Gorillas in the Dzanga-Sangha Reserve, Central African Republic: Implications for Population Estimates and Understandings of Group Dynamics.

Abstract

An analysis of 1231 nests from 163 nest-sites recorded during a twenty-seven month long study (August 1990-NovemberI992) on the feeding ecology oflowland gorillas at the Bai Hokou Study Site, Dzanga-Sangha Dense Forest Reserve, Central African Republic is presented and compared with results from a concurrent nest-count census at the same site as well as results from an earlier census of the regional population and those from other gorilla populations. Nest counts are commonly used 1) to estimate population sizes and densities (Tutin & Fernandez, 1984; Carroll, 1986, 1988; Fay, 1988; Fay & Agnagna, 1992) and 2) to supplement direct observations and thus aid in understanding fluctuations in the size and composition of gorilla groups (Kuroda, 1992; Mitani et. ai., 1993). At the Bai Hokou Study Site, 44 % of gorilla nests recorded during the longitudinal study had no construction. At 15% of nest sites none of the nests were constructed. During a fine-grained census of the same study area, 30% of the nests identified were bare ground nests. These results contrast with reports from other sites of 0-10% bare ground nests (Tutin