Onde moram as águias: distribuição e reprodução de harpia Harpyja, morphnus guianensis e spizaetus spp. No sul do brasil

Abstract

Forest eagles are top predators with many ecological requirements to survive, such as prey availability, wide home ranges, preserved breeding sites, and low anthropic disturbance. Without exception, the five forest eagles that inhabit Rio Grande do Sul are regionally threatened, additionally, two of the species are classified as vulnerable and another one as nearthreatened in Brazil. In order to contribute to the knowledge and conservation of these species, especially in the southern limit of their distributions, we carried out field surveys with active search methodology covering transects (playback) and search using remote technology (drone). Throughout the study, we discovered the first nests of Spizaetus melanoleucus for the southern limit of its distribution. While we discovered the first nests of S. ornatus for the northwest region of this state. Based on the observed distance between nests, we estimated the size of territories of the species S. melanoleucus and S. ornatus in this environment. The estimated areas were of 12.27 and 17.93 km² for each pair. A regional population assessment of Harpia harpyja was also carried out, in which the population capacity supported in the protected forests in the region of the Green Corridor was calculated. We estimated a range of 10–77 pairs (43 as a mean). To conclude our findings, we reported the state rediscovery occurrence of Morphnus guianensis, which had been unrecorded in Rio Grande do Sul for about a hundred years.