“The Fish Hawk may be said to be of mild disposition.  Not only do these birds live in perfect harmony together, but they even allow other birds of very different character to approach so near to them as to build their nests of the very materials of which the outer parts of their own are constructed.  I have never observed a Fish Hawk chasing any other birds whatever.  So pacific and timorous is it, that, rather than encounter a foe but little more powerful than itself, it abandons its prey to the White-headed Eagle, which, net to man, is its greatest enemy . . .

The Fish Hawk differs from all birds of prey in another important particular, which is, that it never attempts to secure its prey in the air, although its rapidity of flight might induce an observer to suppose it perfectly able to do so.  I have spent weeks on the Gulf of Mexico, where these birds are numerous, and have observed them sailing and plunging into the water, at a time when numerous shoals of flying-fish were emerging from the sea to evade the pursuit of the dolphins.  Yet the Fish Hawk never attempted to pursue any of them while above the surface, but would plunge after one of them or a bonita-fish, after they had resumed their usual mode of swimming near the surface.”

–J. J. Audubon, Ornithological Biography, I (1831), 415-16 [excerpted].