Respostas de espécies florestais às alterações ambientais: a ocupação de florestas primárias e secundárias por psitacídeos na Amazônia Central

Abstract

Forest regeneration may help recover old growth habitat loss and possibly buffer the current loss of species due to tropical deforestation. Little is known, however, about the extent to which secondary forests may sustain old growth forest species and about the variability of species responses to regenerating habitats. Parrots offer a good opportunity to study response to regeneration because they are diverse in their responses and include many threatened species. We assessed the differential use of old-growth and secondary forest in nine species of Amazonian parrots, by repeatedly monitoring 155 sites through autonomous sound recording and applying multi-state occupancy models that accounted for imperfect detection. Recorded vocalizations distinguished two states of habitat use: ‘flying use’, when birds just fly over a site, and ‘perching use’, which implies the use of some food, nesting or resting resource. After three decades of forest regeneration, secondary forest still had a negative effect on site use and/or species detection in most species. Seven species showed a lower perching use of secondary forest than old growth, and variability among species was unrelated to body mass or relative brain size. The most negatively affected species also avoided flying over secondary forests, being now considered endemic to the study region and globally endangered. In conclusion, secondary forests appear to lack resources that are necessary for sustaining the whole local community of Amazonian parrots. Site-occupancy studies should be combined with long-term demographic studies to better understand the population-level meaning of the observed differences in habitat use.