The young of the Buteo elegans differs most remarkably from that of B. lineatus; the pattern of coloration appears scarcely the same, for the ochraceous on outer webs of primaries, anterior to their emargination,—which is a feature distinguishing the immature lineatus from all other Buteos,—is in the present bird almost obliterated by the extension of the dusky.
Habits. The Red-shouldered Hawk has an extended distribution, being found more or less abundant from Florida to Nova Scotia, and from the Atlantic to the Pacific coast it is replaced by the Buteo elegans. Mr. J. A. Allen found it by far the most abundant of this family in Florida. In Texas the two races, lineatus and elegans, appear to occur together, Mr. Dresser having met with both near San Antonio. The Red-shouldered Hawk was noticed by this writer from the river Neuces eastward. He found it breeding in the heavily wooded river bottoms of the Medina, and several others of the rivers of Texas, but did not succeed in procuring the eggs. It breeds abundantly in Florida, and thence throughout the United States as far north as Northern Vermont, Nova Scotia, and New Brunswick. Lieutenant Bland notices it as a common and migratory species in Nova Scotia, but Mr. Downes speaks of it as rare near Halifax, where he only met with two specimens. Mr. Boardman gives it as quite common near Calais, breeding there and probably resident. In Western Maine Mr. Verrill regarded the species as a not very common summer resident, where it was also known to breed, as he met with its nest and eggs May 24, 1860. It is quite common in Eastern Massachusetts, where it is found all the year, but where it is more abundant in the fall, from the addition of northern migrants, than at any other time. A few are found throughout the winter, keeping about open springs and in sheltered situations. Mr. Allen also speaks of it as not uncommon in the western part of the same State. It was not taken or seen by Richardson in northern regions, nor does it appear to have been observed in any of the West India Islands.
The history and habits of this very common Hawk seem to have been involved, among earlier writers, in a confusion that seems hardly explicable. Wilson described and always regarded the young and old as two distinct species, calling the former hyemalis, giving to it a northern residence, and the mature bird lineatus. Mr. Audubon repeated this error at first, and sought to demonstrate its correctness by giving to the two forms very dissimilar habits. Bonaparte believed these forms to be identical, and Nuttall did the same, but was altogether in error as to its distribution. He was not aware of its presence in Massachusetts, where it is at times the most abundant of the raptorial birds. This writer only met with it in the Southern States, where he found it very common in swampy situations. He speaks of its having a quailing cry of mutual recognition, which is a plaintive echoing note, like keé-oó, which is continued with little intermission for nearly twenty minutes. He describes the species as not shy, and as very easily approached. These Hawks remain mated throughout the year, and their affectionate treatment of each other is in striking contrast with the selfish indifference of the Red-tail species when their breeding-season is ended.
Nuttall observed it feeding on frogs, cray-fish, and even insects, and rarely troubling larger game. In only one instance did he see one descend upon a Plover. Wilson saw them attack Plover, Sand-pipers, Larks, and even Hawks; but the last is very rare and exceptional. I have never known one of this species to molest the poultry-yard. From 1828 to 1838, during my stay in Roxbury, a pair of these Hawks were residents within a few hundred yards of the house, where, as they never molested the tenants of the barn-yard, they were not allowed to be disturbed. Their breeding-place we could not find, but they kept about an open spring during the winter, feeding upon small game, and were not at all shy. One of them unfortunately was wounded, and was kept in confinement several days. It was the male bird, in full adult plumage, and was by no means wild, feeding readily upon what was given to it, even with our near presence. It would not tolerate a too great familiarity, but manifested great irritation if we attempted to approach it. Its wing had been badly shattered, and it finally died from mortification of the wound. It would never submit to be handled, and fought desperately when we sought to have its limb bound up. After we gave up this attempt as impossible it became rather more familiar, and would even at last greet me with a welcome cry of recognition, and take its food from my hand.
Wilson, in speaking of the adult bird, states that this Hawk has a high and very irregular flight, and is quite different from that of species with longer wings. In his account of the immature plumage, he notes its arrival in Pennsylvania early in November, and its departure in March. He speaks of it as a dexterous catcher of frogs, and adds that it sometimes so stuffs itself that it can fly with difficulty. He has found the remains of ten frogs in the stomach of a single individual.
The Red-shouldered Hawk constructs a large nest, not unlike that of the Crow, in the forked branches of a high tree. It is composed externally of sticks, and is lined with moss and soft leaves. The eggs are four in number, and occasionally three or two. When the nest is approached, the bird utters loud, frequent, and peculiar cries of alarm and resentment, not unlike keé-oó! rapidly repeated, but makes no attempt at resistance. The pair return year after year to the same nest, even when it has been robbed the previous season.
The eggs of this Hawk are of a very uniform spheroidal-oval shape, but slightly pointed at one end, and exhibit certain very general characteristics in the colors of their markings, but vary greatly in their size. The length varies from 2.20 to 2.00, and the breadth from 1.81 to 1.56. The ground-color is usually a dingy white, rarely pure white, and frequently with decidedly brownish tinge. The blotches are most frequently of a yellowish umber color; sometimes blotches of sienna-brown, slate-drab, and more obscure shades of brown are present, and these colors are not unfrequently confusedly mingled. An egg from Cheraw, S. C., has a ground-color of a light drab, tinged with slate and without any blotches whatever. It is not uncommon to find these nearly unspotted eggs in the same nest with others very boldly and profusely blotched. The Cheraw egg measures 2.00 by 1.56 inches; an egg from Massachusetts, 2.20 by 1.81: their relative capacity being nearly as three to four. They average about 2.10 by 1.68 inches.
Mr. L. Heiligbrodt found the nest of this Hawk near Austin, Texas. One egg was taken from the nest, and in a few days after a second was found to have been deposited (S. I. 15,894).
The handsome variety known as B. elegans is generally spoken of by all familiar with its habits, as well as with its appearance, as the almost exact counterpart of the Red-shouldered Hawk, replacing that form on the west coast.