A History of North American Birds; Land Birds; Vol. 3 of 3

by Spencer Fullerton Baird; T. M. Brewer; Robert Ridgway

Mr. MacFarlane’s very complete and careful notes mention, in detail, no less than fifty-eight nests of this species as procured and identified by his party. Of these, forty-six were built on trees, generally spoken of as being large pines, and usually about twenty feet from the ground. Twelve nests were found built on the edge of steep cliffs of shaly mud on the banks of creeks, rivers, and lakes.

The nests that were taken from trees are described as having been built in a crotch, not far from the top, and to have been formed externally of dry twigs, sticks, and small branches, warmly lined with down, feathers, and fine hay. Those found upon cliffs and high river-banks were made of similar materials, but usually with a smaller base of sticks, and a greater supply of hay, moss, and other soft materials. The number of eggs varied from three to five, never more than the latter, and were at times in differing stages of incubation in the same nest. Whenever the nest was approached, the parent birds always manifested great uneasiness, and uttered vociferous screams of distress. The eggs were generally found from the 27th of May to the 25th of June. Those taken after the 20th of June usually contained well-developed embryos. The species was met with by Mr. MacFarlane in great abundance in various localities,—near Fort Anderson, lower down on the Anderson River, near the Arctic coast, and in the vicinity of Rendezvous Lake.

One of the Indians collecting for Mr. MacFarlane informed him that on the 9th of June he discovered the nest of one of these Hawks on a ledge of shaly mud. As he could not kill the parents, he set a snare about the nest. Going to it later in the day, he was disappointed at finding his snare set aside, the eggs gone, and the birds not to be seen. He presumed the parents had removed the eggs, of which there had been three, to a safer place. Several nests were also taken on the shores and among the islets of the Arctic coast, west of Liverpool Bay.

The egg of the Rough-legged Hawk taken by the Storers in Labrador measures 2.06 inches in length by 1.88 in breadth, and is nearly spherical. The ground-color is a soiled white or a light drab, and is marked with a few faint, ill-defined spots of light umber, distributed at intervals over the entire surface.

Two European specimens in my collection are so nearly like the American that the same description would answer for both. They are a trifle larger, but their color and markings are exactly the same. These eggs vary from 2.25 to 2.12 inches in length, and the breadth of each is 1.75 inches. In one specimen the ground-color is of a deeper shade of dingy-white, with larger blotches, and its purplish-slate markings are intermingled with those of umber. A fourth, from Switzerland, varies from most others of this species, and is marked over a cream-colored ground with very numerous and quite large blotches of different shades of umber and sepia-brown. It measures 2.25 by 1.93 inches.

Six eggs taken by Mr. MacFarlane have an average length of 2.18 and an average breadth of 1.79 inches. Their greatest length is 2.24, and their least 2.12 inches. There is but very little variation in their breadth, or only from 1.76 to 1.80 inches. Occasionally these eggs are of a nearly uniform dingy-white, nearly unmarked, and only by very faint cloudings. These cases are rare. Generally they have a creamy-white ground and are boldly marked with blotches of a varying intensity of umber or sepia-brown. Intermingled with these are obscure markings of a purplish-slate.

The dark variety of the Rough-legged Falcon, recognized by some as the A. sancti-johannis, Mr. Ridgway is disposed to regard as rather an individual melanism of the common species, rather than as a distinctive race. In this form it appears to be quite generally distributed over the continent, rather in isolated pairs than as a common bird. It was not taken on the Anderson River by Mr. MacFarlane, where the lagopus style was extremely common, hundreds of skins having been sent by him to the Smithsonian Institution.

The dark-colored birds are seen occasionally in Massachusetts in the winter season, and are usually found frequenting low alluvial tracts in search of small quadrupeds and frogs, and occasionally well-marked specimens have been secured in the neighborhood of Boston. A pair was found breeding near the mouth of the Kennebec River in Maine, and the eggs were secured. They were not readily distinguishable from those of the common Rough-legged Hawk. It is also said, on the authority of Mr. John Krider of Philadelphia, to have been found breeding in New Jersey, and the eggs taken. The parent bird was not secured. These eggs resembled well-marked eggs of the lagopus. Wilson, who observed birds in this plumage on the marshy banks of the Delaware, describes them as remarkably shy and wary, frequenting river-banks, and feeding on mice, moles, and other small game, sailing a good deal and at a great height, which is not the habit of the lagopus, and was seen by him to kill a Duck while on the wing. It has been seen to sit for an hour at a time on a stake by the side of marshes, in an almost perpendicular position, as if dozing. It flies with great ease, and occasionally with great swiftness, and rarely with any flapping of the wings; was most numerous on the Delaware in the winter, but was occasionally to be seen there in the summer. Such is Wilson’s account of its habits as observed by him, and these are partially confirmed by Nuttall from his own observations. It is, however, quite probable that they are mistaken in claiming an essential or specific difference in the habits of the two former. Mr. Audubon regarded it as the adult of the lagopus, and appears not to have been familiar with its habits.

Captain Blakiston mentions the occurrence of the dark bird on the Saskatchewan Plains, where the parent bird and three eggs were obtained by M. Bourgeau, a French collector, in the summer of 1858, and where it is spoken of as not uncommon. Mr. Andrew Murray, in his Contributions to the Natural History of the Hudson Bay Territories, records specimens from Hudson Bay and the country lying between its western shore and Lake Winnipeg. Dr. Gambel speaks of this bird as common in California. Dr. Cooper refers to one obtained by Mr. Lorquin at San Francisco. Mr. Lawrence cites it among the birds of New York. Mr. Boardman gives it as rare near Calais. Mr. Verrill also gives it among the birds of Western Maine, where the lagopus was not observed, but where this form was a regular winter visitant.

The Storers found the Black Hawk not uncommon on the cliffs near Bras d’Or, and their observations of its habits, as contrasted with those of the still more common Rough-legged Hawk, left no doubt in their mind of their specific distinction. While the Black Hawk was observed to be a bold, vigorous, and spirited bird, easy and swift in its motions, and preying upon other birds while on the wing, the Rough-legged was comparatively sluggish, inoffensive, and subsisted only upon rats, mice, moles, frogs, and other small game. A nest containing young birds was found, and one of the latter caught alive. Both old and young were in the same black plumage. The young Hawk was fierce and intractable, and its whole air and manner were utterly unlike the conduct of the young of the other species. Unfortunately, it broke from its confinement and escaped.