Flying through the forest canopy: Movement patterns and habitat selection of rescued and wild Harpy Eagles in the Brazilian Amazon

Abstract

We tracked six Harpy Eagles (Harpia harpyja) by satellite telemetry from 2011 to 2021 in the Brazilian Amazonia, analyzing the used area, movements parameters and habitat selection functions for three of them: one adult within its breeding site, one translocated adult, and a four-years old floating subadult. We used the first-passage time to assess the scale at which these individuals respond to the environment, and the behavioral change point analysis to determine behavioral states parameters across trajectories. We fitted a logistic linear regression model with used-available locations and environmental covariates: slope, Terrain Ruggedness Index (TRI), Normalized Difference Vegetation Index (NDVI), land cover, and habitat edge as predictor variables. Harpy Eagle locations were highly related with “Forest” land cover and high NDVI values. The subadult and the translocated adult selected for “Secondary Forest” within their home ranges, which highlights the importance of this type of habitat in fragmented landscapes. In addition, we found behavioural differences in the movement paths of rehabilitated individuals of Harpy Eagle that are subsequently released to the wild. In conclusion, we suggest including in conservation management not only the nest tree and its immediately surrounding but also an area over landscape scale to optimize and promote the functional connectivity, with a safe and efficient dispersion of immatures. Linking Harpy Eagle´s movement locations to resources (land cover, NDVI), risks (forested habitat edge) and environmental conditions (slope, terrain ruggedness) is an opportunity to learn about habitat selection by this large canopy predator. The Harpy Eagle movement ecology has a potential relationship with the spatial dynamics of prey in the forest canopy, which needs to be further addressed in future research.