I heard the harpy eagle is the strongest bird of prey, and i heard the Philippine is the strongest bird of prey, but the harpy eagle has bigger feet, and and talon's and heavier on mass too. On the other hand, the philippine is bigger in dimension's and are lighter and have longer waist, but not as thick as a harpy eagle, and eat bigger prey like the one recorded to lift a 30lbs curvus dear and have the biggest wing span, but fairly short since it's a forest eagle like the harpy, which is stronger and faster.