Efeitos da estrutura da floresta de Terra-Firme no uso de habitat em corujas (Aves, Strigiformes) na Amazônia Central

Abstract

Owls, despite a well-established role in prey regulation and biological control, are a poorly-studied avian group. For Neotropical species distribution and abundance are especially poorly known. Structural components of forests have been used to explain patterns of owl habitat use and community structure, but such analyses have largely focused on species in the northern hemisphere. The present study examines whether components of forest structure influence habitat use (occurrence and abundance) for six species of owls in an upland Terra firme forest in central Amazonian Brazil. Between October and November 2012, a playback method was used to sample occurrence and abundance in 30 points, each separated from the next by 1km. Multiple linear models revealed relationships between the abundance of four owl species and components of forest structure associated with food availability: Glaucidium hardyi (Amazonian Pygmy Owl) had greater abundance as increased of the distance to nearest creek, with p = 0.023, Megascops watsonii (Northern Tawny-bellied Screech Owl) was more abundant with decreasing leaf litter depth, with p = 0.045, the abundance of the Lophostrix cristata (Crested Owl) and Pulsatrix perspicillata (Spectacled Owl) increased along with the abundance of dead fallen trunks on forest floor, with p = 0.042, end p = 0.009, respectively. A multiple logistic regression also revealed a significant association (p = 0.050) between the occurrence of Pulsatrix perspicillata (Spectacled Owl) and abundance of dead fallen trunks on forest floor. The influence of the components of forest structure differs according to the owl species, demonstrating interspecific differences in micro-habitat use, and reflecting the importance of food resource availability in owl habitat choice.