Contributions to the study of the fauna of Colombia XIV

New observations on Oroaëtus isidori (Des murs)

Abstract

In recent years several nests of this extremely rare eagle have been located. Due to this happy circumstance, the author was able to study this interesting species in their shelters, and take what are probably the only known photographs of this species in the wild, most of them in color. They build their home in the tallest trees in the area, usually oaks, and nest building takes about two months. The size of the nest is about four feet high by seven feet in diameter. The hatchling is usually born in June, covered at first with white down, quickly acquires scapular, wing and tail feathers, and is ready to leave the nest when it is three and a half to four months old. The white and marbled plumage of the young lasts two years; then the dark coloration begins to appear during the third year, but the adult plumage is not attained until after the fourth year. It appears that it is the male that carries all the food during breeding, while the female stands guard at or near the nest. The species has been found in many different biotopes, from the high Páramos to almost the coast of the sea. But, its suitable habitat is the densely forested and clouded slopes of the Andes, from Venezuela to Bolivia, preferring elevations of 6,000 to 7,000 feet, and on the eastern side of the Cordilleras. at least for the location of its nests. The proper name in Spanish proposed for this beautiful Eagle is: Aguila Real de Montaña. Its closest allies in the author's opinion are: Spizastur melanoleucus and Spizaetus ornatus among the neotropical eagles.