The Fish Hawk nests almost invariably on the tops of trees, and this habit has been noticed in all parts of the country. It is not without exceptions, but these are quite rare. William H. Edwards, Esq., found one of their nests constructed near West Point, New York, on a high cliff overhanging the Hudson River. The trees on which their nests are built are not unfrequently killed by their excrement or the saline character of their food and the materials of their nest. The bird is bold and confiding, often constructing its nest near a frequented path, or even upon a highway. Near the eastern extremity of the Wiscasset (Me.) bridge, and directly upon the stage-road, a nest of this Hawk was occupied several years. It was upon the top of a low pine-tree, was readily accessible, the tree being easily climbed, and was so near the road that, in passing, the young birds could frequently be heard in their nest, uttering their usual cries for food. The nests are usually composed externally of large sticks, often piled to the height of five feet, with a diameter of three. In a nest described by Wilson, he found, intermixed with a mass of sticks, corn-stalks, sea-weed, wet turf, mullein-stalks, etc., the whole lined with dry sea-grass (_Zostera marina_), and large enough to fill a cart and be no inconsiderable load for a horse. When the nest of this Hawk is visited, especially if it contain young, the male bird will frequently make violent, and sometimes dangerous, attacks upon the intruder. In one instance, in Maine, the talons of one of these Hawks penetrated through a thick cloth cap, and laid bare the scalp of a lad who had climbed to its nest, and very nearly hurled him to the ground. A correspondent quoted by Wilson narrates a nearly similar instance of courageous and desperate defence of the young. They are very devoted in their attentions to their mates, and supply them with food while on the nest. Wilson relates a touching instance of this devotion, where a female that had lost one leg, and was unable to fish for herself, was abundantly supplied by her mate. In some localities the Fish Hawk nests in large communities, as many as three hundred pairs having been observed nesting on one small island. When a new nest is to be constructed, the whole community has been known to take part in its completion. They are remarkably tolerant towards smaller birds, and permit the Purple Grakle (_Quiscalus purpureus_) to construct its nests in the interstices of their own. Wilson observed no less than four of these nests thus clustered in a single Fish Hawk’s nest, with a fifth on an adjoining branch.