Photo taken at the Zoo in Georgetown. A brief description of the Harpy Eagle from Guyana Birding .com The largest eagle in the Americas and one of the largest and most powerful birds of prey in the world, the Harpy Eagle is often called the "Flying Wolf". It has slate-black feathers above and a white/light grey underside, with a black band across the chest. An unusual double crest of grey head feathers - raised when the bird is alerted or angry - adds to its formidable appearance. A facial disk of feathers, similar to that of an owl, helps focus sound waves and provides for enhanced hearing capabilities.  Read more here http://guyanabirding.com/trellis/feature_bird_E_news_May_07