Mr. Allen reports this species as abundant everywhere in Florida, and as especially so around the lakes of the Upper St. Johns, where it commences nesting in January. At Lake Monroe he counted six nests from a single point of view. It is said by fishermen to occur on the coast of Labrador, but it is not cited as found there by Mr. Audubon, nor is it so given by Dr. Coues. It is, however, very common on the coast of Nova Scotia, breeding in the vicinity of most of the harbors. It is given by Mr. Boardman as common near Calais, where it arrives about the 10th of April, and remains until the middle of September. It is found along the whole coast more or less abundantly, especially near the heads of the numerous estuaries.
In Central America it is cited by Salvin as occurring abundantly on both the coast regions, and is particularly common about Belize, where it is believed to breed. It is said by Mr. Newton to be found on the island of St. Croix at all times except during the breeding-season. It was also occasionally seen at Trinidad by Mr. E. C. Taylor.
The Fish Hawk appears to subsist wholly on the fish which it takes by its own active exertions, plunging for them in the open deep, or catching them in the shallows of rivers where the depth does not permit a plunge. Its abundance is measured somewhat by its supply of food; and in some parts of the country it is hardly found, in others it appears in solitary pairs, and again in a few districts it is quite gregarious.
The American Fish Hawk is migratory in its habits, leaving our coasts early in the fall of the year, and returning soon after the close of the winter. Sir John Richardson states that the time of its arrival in the fur regions is as early as April, and on the coast it has been noticed in the middle of March. It breeds on the coast of Nova Scotia late in June, on that of Maine earlier in the same month, in New Jersey and Maryland in May, and still earlier in California.
It is said to arrive on the New Jersey coast with great regularity about the 21st of March, and to be rarely seen there after the 22d of September. It not unfrequently finds, on its first arrival, the ponds, bays, and estuaries ice-bound, and experiences some difficulty in procuring food. Yet I can find no instance on record where our Fish Hawk has been known to molest any other bird or land-animal, to feed on them, though their swiftness of flight, and their strength of wing and claws, would seem to render such attacks quite easy. On their arrival the Fish Hawks are said to combine, and to wage a determined war upon the White-headed Eagles, often succeeding by their numbers and courage in driving them temporarily from their haunts. But they never attack them singly.
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.
The eggs of the Fish-Hawk are usually three in number, often only two, and more rarely four. They are subject to great variations as to their ground-color, the number, shade, and distribution of the blotches of secondary coloring with which they are marked, and also as to their size and shape. Their ground-color is most frequently a creamy-white, with a very perceptible tinge of red. This varies, however, from an almost pure shade of cream, without any admixture, to so deep a shade of red that white ceases to be noticeable. Their markings are combinations of an almost endless variation of shades of umber-brown, a light claret-brown, an intermingling of both these shades, with occasional intermixtures of purplish-brown. They vary in length from 2.56 to 2.24 inches, and in breadth from 1.88 to 1.69 inches. It would be impossible to describe with any degree of preciseness the innumerable variations in size, shape, ground-color, or shades of markings, these eggs present. They all have a certain nameless phase of resemblance, and may be readily distinguished from any other eggs except those of their kindred. There are, however, certain shades of wine-colored markings in the eggs of the Fish Hawk of Europe, and also in that of Australia, that I have never noticed in any eggs of the American bird; but that this peculiarity is universal I am not able to say. The smallest egg of the carolinensis measures 2.31 by 1.62 inches; the largest, 2.56 by 1.88.