A History of North American Birds, Land Birds. Volume 3. Robert Ridgway

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      Habits. In treating of the general habits of the Gerfalcons of North America it will not be necessary, nor will it be possible, to give the distinctive peculiarities belonging to the several forms in which these Falcons occur. Whether, on account of their variations of plumage, we consider them as races or as specifically distinct, does not affect their history in this respect. There is no good reason for presuming that they have any very noticeable variations as to any of their habits, although certain writers claim for some of them certain well-marked peculiarities of character.

      In the matter of geographical distribution they are all, for the most part, rarely seen, even in midwinter, south of the 50th parallel of north latitude, and are found in the summer as far north as the Arctic Ocean. The Gerfalcon of the McKenzie River region, occurring from the Slave Lake to Anderson River and the Yukon, is the form elsewhere given as the F. sacer. Along our eastern coast region occurs another form, the F. labradora, which is the bird met with in Labrador, and described by Mr. Audubon. The F. candicans or grœnlandicus is a form peculiar to Greenland, visiting also, in the winter, the Hudson’s Bay region; while the F. islandicus, a well-known European form, occurs in Greenland also, and occasionally farther south.

      Holböll, in his account of the birds of Greenland (Isis, 1845), appears to recognize but one species of Gerfalcon as occurring there, to which he gives the name of islandicus. This is, he states, the most abundant Falcon in Greenland, and is equally common in the northern and in the southern parts. Their great variations in color he regarded as indicative of differences in ages to only a very limited extent, and as in no respect specific. These differences in color were found among both nestlings and breeding birds, white and dark birds being found together in both circumstances. The white birds were more numerous in Northern Greenland, and the dark ones oftener seen in the southern portion.

      He found the young birds moulting throughout the winter. On the 4th of January, 1840, he shot a young female that showed signs of moulting about the head and neck, with a striped white appearance from the sprouting feathers. The ovaries were quite well developed, and it was evident that the birds of this species breed in the first season after their birth. Holböll adds that they breed in January, that their eggs are of nearly the same color as those of the Ptarmigan, but are twice as large. They nest usually in inaccessible cliffs. They prey chiefly upon water-fowl and Ptarmigans, and usually build near “bird rocks,” from which they obtain the young without much trouble. He mentions having once seen one with a young Larus tridactylus in each foot, and another with two Tringa maritima carried in the same manner. Its rapidity of flight Holböll did not regard as very great. He had for years kept pigeons, and only lost two young birds, which were seized when at rest. Almost every day, especially in October and November, these Falcons would chase the old Pigeons unsuccessfully, and were often shot when they followed them too near the house. They were not particularly shy, and were occasionally decoyed and killed by throwing a dead bird towards them.

      During the summer they are most numerous along the bays, especially where there are “bird-rocks” near. In September they go southerly along the coast, and also in October and November. At this time they are not rare, and approach the houses of the Danes, near which they are often seen fighting with the Ravens. Their spring migrations are not so regular as they are in the autumn, or perhaps at this time they do not approach the houses so frequently. When they are near the settlements, it is noticed that in the morning they fly towards the south, and in the evening towards the north.

      Richardson speaks of the Gerfalcon as a constant resident in the Hudson Bay territory, where it is known as the Speckled Partridge-Hawk, and also as the Winterer. Its southern limit he could not give, but he never met with it south of 52°. He traced it northward to the coast of the Arctic Sea, and probably to the most northern Georgian islands. He cites Captain Sabine as authority for its occurring as far north as latitude 74° on the west coast of Greenland. Richardson often met with it during his journeys over the Barren Grounds, where its habitual prey was the Ptarmigan, and where it also destroyed Plover, Ducks, and Geese. He relates that in the middle of June, 1821, a pair of these birds attacked him as he was climbing to the vicinity of their nest, which was built on a lofty precipice on the borders of Point Lake, in latitude 65° 30′. The bird flew in circles, uttering loud and harsh screams, stooping alternately with such velocity that their motions through the air produced a loud rushing noise. They struck their claws within an inch or two of his head. Keeping the barrel of his gun close to his cheek, and suddenly elevating its muzzle when they were in the act of striking, he found that they invariably rose above the obstacle with the rapidity of thought, showing equal power of motion. They bore considerable resemblance to the Snowy Owl, but their flight was much more rapid.

      Mr. MacFarlane, in the memoranda of his collections in the neighborhood of Anderson River and Fort Anderson, furnishes notes of eighteen nests of the Gerfalcon obtained by him in that region. With only two exceptions, these were placed near the tops of pines, or other trees, at distances from the ground varying from ten to twenty-five feet. In some instances the nest was placed on the very top of the tree, in others on a lower limb against the trunk. They were composed of twigs and small branches, and lined with mosses, hay, deer’s hair, feathers, and other substances. The parents were always very much excited whenever their nests were approached, making a great noise, and not unfrequently their loud screams drew attention to nests that would otherwise have escaped notice. In one instance a nest had been built on a ledge of rocks thirty miles northwest of Fort Anderson. It was composed of a few withered twigs, and lined with mosses and hay. It was found on the 27th of May, and contained two eggs nearly fresh, and two in a state of greater development. One nest, placed on a broad branch of a tree, near the СКАЧАТЬ