The highly interactive nature of predator-prey relationship is essential for ecosystem conservation; predators have been extirpated, however, from entire ecosystems all over the Earth. Reintroductions comprise a management technique to reverse this trend. Species Distribution Models (SDM) are preemptive tools for release-site selection, and can define levels of habitat quality over the species distribution. The Atlantic Forest of South America has lost most of its apex predators, and Harpy Eagles Harpia harpyja —Earth’s largest eagle—are now limited to few forest pockets in this domain. Harpy Eagles are supposedly widespread in the Amazon Forest, however, where habitat loss and degradation is advancing at a rapid pace. We aim to describe the suitability of threatened Amazonian landscapes for this eagle. We also aim to assess the suitability of remaining Atlantic Forest sites for Harpy Eagle reintroductions. Here we show that that considerable eagle habitat has already been lost in Amazonia due to the expansion of the “Arc of Deforestation”, and that Amazonian forests currently represent 93% of the current distribution of the species. We also show that the Serra do Mar protected areas in southeastern Brazil is the most promising region for Harpy Eagle reintroductions in the Atlantic Forest. Reintroduction and captive breeding programs have been undertaken for Harpy Eagles, building the technical and biological basis for a successful restoration framework. Our distribution range for this species represents a 41% reduction of what is currently proposed by IUCN. Furthermore, habitat loss in Amazonia, combined with industrial logging and hunting suggest that the conservation status of this species should be reassessed. We suggest researchers and conservation practitioners can use this work to help expand efforts to conserve Harpy Eagles and their natural habitats.

Knowledge of the food habits of threatened taxa is key for their effective conservation, especially in top predators where prey species are frequently also hunted by humans. The harpy eagle Harpia harpyja is the largest living eagle, and is considered Near Threatened by the IUCN. Its main threats are persecution by humans and habitat loss. Predation patterns of this species have been the subject of several descriptive studies, each reflecting the idiosyncrasies of the study area. Systematizing these data permits a transition from descriptive treatments of harpy food habits to a predictive focus, based on defensive prey strategies and foraging theory. This generates information that can enhance management and conservation decisions. Literature data were summarized and standardized, allowing comparison between studies. Results indicate that harpy eagles feed mainly on sloths and other prey with passive antipredator strategies, with sloths accounting for 50% of prey items and biomass consumed. Large monkeys such as howlers (Alouatta spp.) and capuchins (Sapajus and Cebus spp.) are the next most important prey, but combined, primates form only ~20% of the consumed prey biomass. Predation seldom occurs on animals weighing more than 5 kg. This is positive from a conservation point of view, since sloths are not game species, precluding competition between harpy eagles and subsistence hunting.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.