Spatial Variation in Population Density of an Endemic and Endangered Bird, the Cauca Guan (Penelope Perspicax)

Abstract

Endemic species tend to be habitat specialists with low population densities, but densities may vary among sites and may be temporally dynamic. In addition, species may exhibit plasticity in habitat use, with the result that densities vary in different habitats. The Cauca Guan ( Penelope perspicax) is an endangered species endemic to the mid-Cauca Valley in Colombia. To assess spatial variation in population densities, we surveyed different habitat types (mature and secondary forest, early regeneration, and vegetation strips along streams) in three sites and compared them to densities reported in previous studies to explore possible changes over a period of several years. At the three sites, densities varied between 10 and 40 birds/km2 in different habitats. Variation in population density may be related to forest area and habitat productivity, but guans are known to move among locales and regions in response to temporal fluctuations in resource availability. Cauca Guan densities are comparable to those of other montane Penelopine guans with broader geographic distributions. Although the Cauca Guan is not a habitat specialist and may reach high densities under some conditions, globally this guan remains rare and efforts for its conservation should be sustained.