Distribuição e Ecologia do Uiraçu-falso (Morphnus guianensis, Daudin 1800)

Abstract

The Crested Eagle, Morphnus guianensis (Daudin, 1800) is the second-largest forest eagle of the Americas, found from Mexico to southern Brazil, Argentina and Paraguay. Despite its large size and wide distribution, it is one of the least-known Neotropical raptors. It is considered "Near-threatened" according to IUCN criteria, and studies on its biology and ecology are needed. Our goals in the first chapter were to review the distribution of the Crested Eagle, and based on the Brazilian Harpy Eagle Conservation Program (PCGR database), literature, online databases, zoos, wild and museum records, we provide an updated distribution map with 37 points outside the IUCN map. Far from the border (>40 km) we found 21 records, contributing to an expansion of the known range and habitat. At the northernmost extreme of distribution, the range was extended north to Southern Mexico; in Nicaragua, we extended the range farther south in the north, and to the southern border with Costa Rica. In Colombia, an old specimen was located between Darien Peninsula and Perija Mountains. In Central Brazil a record from the ecotone between Cerrado and Gallery Forest, and another in an upland remnant of Atlantic Rainforest expands the range towards southeastern Brazil, and in the Southeast, an old record expands the Atlantic Rainforest distribution. In the second chapter, we studied reproductive aspects of the species based on two complete reproductive cycles (from birth to the first outside-the-nest flights), in two nests, one in terra firme and another in flooded forest. Two eggs were observed per nest. Only the female incubated, and we photographed post-hatching copulation of the pair, with the chick at 17 days old. We present the first photographs of eggs and chicks in the wild. The first flights outside the nest at (101-122 days), and its movements using perches near the nest, improve with age; at 145 days it flew a maximum of 64-120 m and about 150 m at 230 days. In the third chapter we described and compared the diet between the two forest types cited above. There were no quantitative or qualitatively significant statistical differences between forest types. Caluromys lanatus and Saguinus midas were restricted to terra firme, and Isothryx cf. negrensis, Coendu sp., Callicebus caligatus and Saguinus labiatus were restricted to flooded forest. We propose foraging strategies used by adults. We identified 21 and add 16 new prey species from different groups (76% mammals, 19% reptiles and 5% birds), with all occupying similar ecological niches (nocturnal/crepuscular species that use diurnal refuges).