Riesenseeadler
Some wing and leg remains of Haast's eagles permit direct comparison with living eagles. The harpy eagle ("Harpia harpyja"), the Philippine eagle ("Pithecophaga jefferyi"), and the Steller's sea eagle ("Haliaeetus pelagicus") are the largest and most powerful living eagles, and the first two also have a similarly reduced relative wing-length as an adaptation to forest-dwelling. A lower mandible from the Haast's eagle measured and the tarsus in several Haast's eagle fossils has been measured from . In comparison, the largest beaks of eagles today (from the Philippine and the Steller's sea eagle) reach a little more than ; and the longest tarsal measurements (from the Philippine and the Papuan eagle) top out around .