The basic ecology of most of the Andean guans is poorly known. However, knowledge of the natural history of members of Cracidae has increased in the last decade, but most studies involve lowland species. We present basic natural history data for the Sickle-winged Guan (Chamaepetes goudotii) on the western slope of the Central Range of the Andes, Colombia. The density estimate for the Sickle-winged Guan in the study area was 13.7 individuals/km 2 and the mean ( SD) group size was 1.5 0.76 individuals. These groups used all forest strata but usually foraged in the middle stratum (8.6 6.1 m). The diet consisted of fruits (84.5%), flowers (3.9%), leaves (5.8%), and invertebrates (5.8%). We observed wing-drumming displays, nests, and fledglings from January through June. We discuss the ability of the Sickle-winged Guan to colonize and establish populations in restored habitats. Received 3 April 2006. Accepted 6 September 2006.