Resumen

Endemic species with distributions restricted to narrow elevational ranges in the Andes are among the least-known tropical birds and are also among the most vulnerable to anthropogenic pressures of climate change and habitat fragmentation. One such species is the Peruvian Piedtail (Phlogophilus harterti), a hummingbird endemic to the Andean foothills of central and southern Peru. To obtain basic ecological information and estimate population densities, we studied Peruvian Piedtails over an 12-year period (2006–2017) along an elevational gradient in Manu National Park in Peru. We calculated a density of 57.9 (95% CI: 36.2–81.4) individuals per km2, which is similar to estimates reported for other range-restricted Andean hummingbirds. Peruvian Piedtails were found at elevations between 867–1545 m, but were more common in areas with undisturbed forest, dense vegetation, and bamboo patches in a narrow elevational band of 400 m (900–1300 m). All nests were in dense clumps of hanging moss, and clutches always consisted of two eggs. The duration of incubation (19 d) and nestling (23 d) periods was within the range reported for other hummingbirds of similar size, but the growth rate of nestlings (K = 0.28) was relatively slow. Our observations suggest that Peruvian Piedtails are locally common, but only in specific habitats within their limited elevational range in southeastern Peru, and they may rely on patches of bamboo (Guadua sp.) for breeding. Thus, the broader extent of the occurrence and density of Peruvian Piedtails across their range should be evaluated to better inform their conservation status.