Subgenera.

The species of this genus are exceedingly numerous, about fifty-seven being the number of nominal “species” recognized at the present date. Among so many species, there is, of course, a great range of variation in the details of form, so that many generic and subgeneric names have been proposed and adopted to cover the several groups of species which agree in certain peculiarities of external structure. That too many genera and subgenera have been recognized is my final conclusion, after critically examining and comparing forty of the fifty-seven species of Gray’s catalogue (Hand List of Birds, I, 1869, pp. 29–35). The variation of almost every character ranges between great extremes; but when all the species are compared, it is found that, taking each character separately, they do not all correspond, and cross and re-cross each other in the series in such a manner that it is almost impossible to arrange the species into well-defined groups. From this genus I exclude Lophospiza, Kaup (type, L. trivirgatus); Asturina, Vieill. (type, A. nitida); Rupornis, Kaup (type, R. magnirostris); Buteola, Dubus (= Buteo, type, B. brachyura, Vieill.); included by Gray under Astur, as subgenera, and Tachyspiza, Kaup (type, T. soloensis); and Scelospiza, Kaup (type, S. francesii); which are given by Gray as subgenera of Micronisus, Gray (type, Accipiter gabar), the species of the typical subgenus of which, as arranged in Gray’s Hand List, I refer to Nisus. All these excluded names I consider as representing distinct genera.

The species of this genus are noted for their very predatory disposition, exceeding the Falcons in their daring, and in the quickness of their assault upon their prey, which consists chiefly of small birds.

Subgenus NISUS, Cuvier.

• Accipiter, Brisson, 1760.⁸¹
• Nisus, Cuvier, 1799. (Type, Falco nisus, Linn.; A. fringillarius (Ray), Kaup.)
• Jerax, Leach, 1816. (Same type.)
• Cooperastur, Bonap. 1854. (Type, Accipiter cooperi, Bonap.)
• Hieraspiza, 1844, Jeraspiza, 1851, and Teraspiza, 1867, Kaup. (Type, Falco tinus, Lath.)
• Hieracospiza, Agass. (Same type.)
• Urospiza, 1845, Urospizia, 1848, and Uraspiza, 1867, Kaup. (Type, Sparvius cirrhocephalus, Vieill.)
• Erythrospiza, Kaup, 1867. (Type, A. trinotatus (Temm.?))
• Micronisus, Gray, 1840. (Type, Falco gabar, Daud.)
• Nisastur, Blas. 1844. (Same type.)

The species of this subgenus are generally of small size and slender form; but with a graceful and apparently delicate structure they combine remarkable strength and unsurpassed daring. They differ from the species of Astur mainly in less robust organization. The species are very numerous, and most plentiful within the tropical regions. The Old World possesses about thirty, and America about fifteen, nominal species. Several South American species are intimately related to the two North American ones, and may prove to be only climatic races of the same species; thus, erythrocnemis, Gray (Hand List, p. 32, No. 305) may be the intertropical form of fuscus, and chilensis, Ph. and Landb. (Hand List, No. 314), that of cooperi. But the material at my command is too meagre to decide this.

In consequence of the insufficient material for working up the South American species, I shall omit them all from the following synopsis of the North American species and races.⁸²

Species and Races.

Nisus fuscus (Gmel.) Kaup.
SHARP-SHINNED HAWK.

Falco fuscus, Gmel. Syst. Nat. p. 283, 1789.—Lath. Ind. Orn. p. 43, 1790; Syn. I, 98, 1781; Gen. Hist. I, 283, 1821.—Mill. Cim. Phys. pl. xviii, 1796.—Daud. Tr. Orn. II, 86, 1800.—Shaw, Zoöl. VII, 161, 1809.—Aud. B. Am. pl. ccclxxiii, 1821; Orn. Biog. IV. 522, 1831.—Brew. (Wils.) Am. Orn. 685, 1852.—Peab. B. Mass. III, 78, 1841.—Thomp. Nat. Hist. Verm. p. 61, 1842.—Nutt. Man. 87, 1833. Accipiter fuscus, Bonap. Eur. & N. Am. B. p. 5, 1838; Consp. Av. 32, 1850.—Gray, List B. Brit. Mus. 38, 1844; Gen. B. fol. sp. 4, 1844.—Cass. B. Cal. & Tex. 95, 1854; Proc. Ac. Nat. Sc. Phil. 1855, 279; Birds N. Am. 1858, 18.—Strickl. Orn. Syn. I, 108, 1855.—Woodh. Sitgr. Exp. Zuñi & Colorad. p. 61, 1853.—Cooper & Suckley, P. R. R. Rep’t, VII, ii, 146, 1860.—Heerm. Williamson’s Rep. 33.—Newb. Williamson’s Rep. 74.—Coues, Pr. Ac. Nat. Sc. Phil. Jan. 1866, p. 7.—Blakist. Ibis, III, 1861, 317 (fresh eggs).—Gray, Hand List, I, 32, 1869. Astur fuscus, De Kay, N. Y. Zoöl. II, 17, pl. ii, fig. 2 (juv. ♂), 1844.—Giraud, B. Long Isl’d, p. 19, 1844. Nisus fuscus, Kaup, Monog. Falc. Cont. Orn. 1850, p. 64. Falco dubius, Gmel. Syst. Nat. 1789, p. 281.—Lath. Ind. Orn. p. 43, 1790; Syn. Supp. I, 37, 1802; Gen. Hist. I, 279, 1821.—Daud. Tr. Orn. 1800, II, 122. Falco velox, Wils. Am. Orn. pl. xlv, f. 1, 1808.—Bonap. An. Lyc. N. Y. II, 29, 1433; Isis, 1832, p. 1137. Accipiter velox, Beech. Voy. Zoöl. p. 15. Astur velox, James. (Wils.) Am. Orn. I, 68, 1831. Falco pennsylvanicus, Wils. Am. Orn. pl. xlvi, fig. 1, 1808.—Lath. Gen. Hist. I, 280, 1820.—Temm. Pl. Col. 67. Accipiter pennsylvanicus, Vig. Zoöl. Journ. I, 338.—Steph. Zoöl. XIII, ii, 32, 1815.—Rich. Faun. Bor.-Am. II, 44, 1831.—Jard. (Wils.) Am. Orn. II, pp. 210, 215, 1832.—Swains. Classif. B. II, 215, 1837. Astur pennsylvanicus, Less. Man. Orn. I, 92.—James. (Wils.) Am. Orn. I, 70, 1831. Nisus pennsylvanicus, Cuv. Règ. An. (ed. 2), I, 334, 1829.—Less. Tr. Orn. p. 59, 1831. Falco columbarius, var., Shaw. Zoöl. VII, 189, 1809. Accipiter ardosiacus, Vieill. Enc. Méth. III, 1274, 1823. Accipiter fringilloides (not of Vigors!), Jard. (Wils.) Am. Orn. II, 215, 1832. ? Nisus pacificus, Lesson, Man. et d’Oiseaux, 1847, 177 (Acapulco to California. Square tail). Accipiter fuscus, Brewer, Oölogy, 1857, 18, pl. III, f. 23, 29; pl. V, f. 54.

Specimens from different regions vary but little in size. The largest are 4,198, ♀, San Francisco, Cal., winter, 16,957, ♀, Hudson’s Bay Territory, and 55,016, ♀, Mazatlan, Mexico, in which the wing ranges from 8.40 to 8.50, the tail 7.00. The smallest females are 45,826, Sitka, Alaska, and 11,791, Simiahmoo, W. T., in which the wing measures about 7.80. A female (32,499) from Orizaba, Mexico, one (8,513) from Fort Yuma, Cal., and one (17,210) from San Nicholas, Lower California, have the wing 8.00, which is about the average. The largest males are 54,336, Nulato, Alaska, 58,137, Kodiak, Alaska, 27,067, Yukon, mouth of Porcupine, and 55,017, Mazatlan, Mexico, in which the wing measures 7.00, the tail 5.60. The smallest males are 5,990, Orange, N. J., 8,514, Shoalwater Bay, W. T., 21,338, Siskiyou Co., Cal., 37,428, Orizaba, Mexico, and 5,584, Bridger’s Pass, Utah; in this series the wing measures 6.50–6.70, the tail 5.40–5.60. A specimen from Costa Rica measures: wing 6.70, tail 5.35. Thus the variation in size will be seen to be an individual difference, rather than characteristic of any region. Some immature specimens from the northwest coast of North America (as 45,828, ♂, Sitka, Rus. Am., 5,845, ♂, Fort Steilacoom, W. T., 11,791, Simiahmoo, Puget Sound, and 8,514, Shoalwater Bay, W. T.) are much darker than others, the brown above inclining to blackish-sepia; no other differences, however, are observable. An adult from the Yukon (54,337, ♀) has the rufous bars beneath remarkably faint, although well defined; another (19,384, ♀, Fort Resolution), in immature plumage, has the longitudinal markings beneath so faint that they are scarcely discernible, and the plumage generally has a very worn and faded appearance. A male in fine plumage (10,759, Fort Bridger, Utah) has the delicate reddish-rufous beneath so extended as to prevail, and with scarcely any variegation on the sides and tibiæ; the bars on the tail, also, are quite obsolete.

Habits. This species is one of the most common Hawks of North America, and its geographical range covers the entire continent, from Hudson’s Bay to Mexico. Sir John Richardson mentions its having been met with as far to the north as latitude 51°. Drs. Gambel and Heermann, and others, speak of it as abundant throughout California. Audubon found it very plentiful as far north as the southern shore of the Gulf of St. Lawrence. It has been obtained in New Mexico by Mr. McCall, in Mexico by Mr. Pease, in Washington Territory by Dr. Cooper and Dr. Suckley, in Alaska by Mr. Dall, at Fort Resolution by Mr. Kennicott, at Fort Simpson by Mr. B. R. Ross, etc. Messrs. Sclater and Salvin give it as a rare visitant of Guatemala. It has been ascertained to breed in Massachusetts, New Jersey, Wisconsin, California, and Pennsylvania, and it probably does so not only in the intervening States and Territories, but also in all, not excepting the most southern, Florida, where its nest was found by Mr. Wurdemann.

Dr. Woodhouse, who frequently observed this bird skimming over the prairies while in search of its prey, states that its flight is so peculiar that there is no difficulty in recognizing it, when taken in connection with its form, short wings, and long tail, being very swift and irregular in its movements, first high in the air, then close to the ground, suddenly disappearing among the grass when it has seized the object of which it was in pursuit.

Mr. Dresser met with this Hawk in Texas, but nowhere south or west of San Antonio, where it remains through the breeding-season, nesting in the dense cedar-thickets.

Mr. Audubon regarded it as the very miniature of the Goshawk, in its irregular, swift, vigorous, varied, and yet often undecided, manner of flight, and on occasion greatly protracted. When in search of its prey, it is said to pass over the country, now at a moderate height, now close over the land, and with a surprising swiftness. It advances by sudden dashes, and pounces upon the object of its pursuit so suddenly as to render hopeless any attempt to escape. It has frequently been known to seize and kill a bird so large that it was unable to carry it, and had to drop to the ground with it. In one instance Mr. Audubon saw it strike a Brown Thrush, which it had darted into a thicket of briers to seize, emerging at the opposite side. As Mr. Audubon ran up, the Hawk attempted twice to rise with its prey, but was unable to carry it off, and relinquished it. The Thrush was quite dead, and had evidently been killed instantly.

Mr. Downes, of Halifax, who speaks of this Hawk as common in Nova Scotia, breeding all over that province, adds that it does not molest the poultry-yards, being too weak to attack large prey. But this is not universally the case. They are frequently destructive both to dove-cots and to the younger inhabitants of the poultry-yard. Mr. Nuttall narrates that in the thinly settled parts of Alabama and Georgia it seemed to abound, and was very destructive to young chickens, a single one having been known to come regularly every day until it had carried off twenty or thirty. He was eyewitness to one of its acts of robbery, where, at noonday and in the near presence of the farmer, the Hawk descended and carried off one of the chickens. In another instance the same writer mentions that one of these Hawks, descending with blind eagerness upon its prey, broke through the glass of the greenhouse at the Cambridge Botanic Garden, fearlessly passed through a second glass partition, and was only brought up by a third, when it was caught, though very little injured.

At times this Hawk is seen to fly high, in a desultory manner, with quick but irregular movements of the wings, now moving in short and unequal circles, pausing to examine the objects below, and then again descending rapidly and following a course only a few feet from the ground, carefully examining each patch of small bushes in search of small birds.

Besides the smaller birds, young chickens, and pigeons, this Hawk has been known to occasionally feed on small reptiles and insects, as also upon the smaller quadrupeds.

Mr. Audubon speaks of having met with three nests of this species, and all in different situations. One was in a hole in a rock on the banks of the Ohio River; another was in the hollow of a broken branch, near Louisville, Ky., and the third in the forks of a low oak, near Henderson, Ky. In the first case, the nest was slight, and simply constructed of a few sticks and some grasses, carelessly interwoven, and about two feet from the entrance of the hole. In the second instance there was no nest whatever, but in the third the birds were engaged in the construction of an elaborate nest. The number of the eggs was four in one instance, and five in another. He describes them as almost equally rounded at both ends; their ground-color white, with a livid tinge, but scarcely discernible amid the numerous markings and blotches of reddish-chocolate with which they were irregularly covered. In a nest which was large and elaborately constructed of sticks, and contained five eggs, found by Dr. H. R. Storer in Concord, Mass., there was a single egg which nearly corresponds with this description. It is, however, the only one among many specimens that at all agrees with it. This specimen is a little more than usually elongate, and its ground-color, which is a purplish-white, is nearly concealed by its blotches of various shades of sepia-brown. In every other instance the egg is very nearly spherical, the ground-color white, and beautifully marked with large confluent blotches of sepia, varying in depth from quite a light to a very dark shade. In one, these confluent markings form a broad belt around the centre of the egg. In others, they are chiefly distributed about the larger end. The contrast between the white ground and the dark confluent dashes of brown is very striking. Except in size, the eggs of this bird bear a marked resemblance to those of the Sparrow Hawk of Europe. In a few instances, the brown markings have an intermixture of red and purple. The egg measures 1.35 by 1.15 inches.

In nearly every instance the nest of this Hawk has been constructed in trees. It is usually large in proportion to the size of the bird, and its materials are somewhat elaborately put together; it is composed chiefly of large sticks and twigs, and the whole platform is covered with a thin lining of dry leaves, mosses, grass, etc. Mr. John Krider, of Philadelphia, found a nest in New Jersey, in the vicinity of that city, which was built on the edge of a high rock.

Mr. Robert Kennicott met with the nest of this species at Fort Resolution. It was composed entirely of small dry spruce twigs, with the exception of a half-dozen small flat bits of the scaly outer bark of the spruce, laid in the bottom, and forming a sort of lining. No feathers or other softer materials were used. The nest was shallow and broad. The base was about eighteen inches in diameter, and was about eight feet from the ground. It was in a small spruce in a thick wood and on high ground. When disturbed, the female flew off a short distance; but on Mr. Kennicott’s hiding himself returned and flew near the nest, continually uttering a harsh rapid note. Near the nest were marks indicating the place where the male passed the nights perched on a dry stick near the ground.

Mr. B. R. Ross observed these birds nesting thickly along the cliffs of the Upper Slave River. They were more rare northward of Fort Simpson than F. columbarius.

Mr. William Street, of Easthampton, informs me that he has found this Hawk nesting on Mount Tom, where he has known of six of their nests in one season. In the spring of 1872 he found three nests, on the 24th and 25th of May. They contained two eggs each. One of these, on the 27th contained three eggs, of which he took one; on the 3d of June two more eggs had been laid. Two of these were taken, after which the birds deserted the nest and resorted to an old squirrel’s nest, where they had four more eggs, depositing one every third day. They arrive at Mount Tom about the 1st of May. Their nests are made entirely of sticks, larger on the outside, and smaller within. They usually build in a hemlock-tree, selecting a thick clump. They are very noisy when they are at work building their nest, and often betray their presence by their cries. The younger the pair the more noisy they are. This Hawk appears to live nearly altogether on small birds. Mr. Street mentions having found ten or twelve skeletons in a single nest of this species.

Nisus cooperi (Bonap.).
Var. cooperi, Bonap.
COOPER’S HAWK.

Falco cooperi, Bonap. Am. Orn. pl. x, fig. 1, 1825; Ann. Lyc. N. Y. II, 433; Isis, 1832, 1137.—James. (Wils.) Am. Orn. IV, 1831, 3.—Peab. B. Mass. III, 78. Accipiter cooperi, Gray, List B. Brit. Mus. 38, 1844; Gen. B. fol. sp. 6.—Cass. Birds Cal. & Tex. p. 96, 1854; Birds N. Am. 1858, 16.—Sclat. Pr. Z. S. 1859, 389 (difference from A. pileatus, Max.).—Heerm. P. R. R. Rep’t, VII, 31, 1857.—Coop. & Suckl. P. R. R. Rep’t, XII, ii, 145, 1860.—Coues, Prod. Orn. Ariz. p. 7, 1866.—Dresser, Ibis, 1865, 323 (Texas).—Blakist. Ibis, III, 1861, 317.—Scl. & Salv. Ex. Orn. I, 1869, 170.—Gray, Hand List, I, 32, 1869. Astur cooperi, Jard. (Wils.) Am. Orn. III, 363, 1832.—Bonap. List, p. 5; Rev. Zool. 1850, 489; Consp. Av. 31.—De Kay, Zoöl. N. Y. II, 18, pl. iv, p. 5.—Newb. P. R. R. Rep’t, VI, iv, 74, 1857.—Max. Cab. Journ. VI, 1858, 13. Falco stanleyi, Aud. B. Am. pls. xxxvi, cxli; Orn. Biog. I, 186. Accipiter pileatus (not of Max.!), Strickl. Orn. Syn. I, 109, 1855. Accipiter cooperi, Brewer, Oölogy, 1857, 20, pl. v, f. 55.

Var. mexicanus, Swainson.
MEXICAN BLUE-BACKED HAWK.

Accipiter mexicanus, Swains. F. Bor.-Am. II, 1831, 45.—Jard. (ed. Wils.) Am. Orn. II, 1832, 215.—Bonap. Consp. 32 (under A. fuscus).—Cass. B. Cal. & Tex. 96.—Ib. P. A. N. S. 1855, 279; Birds N. Am. 1858, 17.—Coop. & Suckl. P. R. R. Rep’t, VII, ii, 1860, 146.—Coues, P. A. N. S. Philad. 1866, 18.—Gray, Hand List, I, 1869, 33.

Habits. This common Hawk appears to have a very general distribution over the United States, from South Carolina to New Brunswick, on the Atlantic; from Texas, New Mexico, and Arizona, in the interior, to the Saskatchewan, and from Southern California to Washington Territory, on the Pacific. Mr. Boardman mentions it as found near Calais, but rare. Mr. Verrill cites it as occurring in Western Maine, but not common. I have received its eggs from South Carolina, where it is resident throughout the year. Mr. Dresser met with it not uncommon near San Antonio, and found it breeding on the Altascosa and Medina Rivers. Dr. Coues says it is generally distributed throughout the Territory of Arizona. Dr. Newberry found it common about San Francisco, and extending north of the Columbia River. Mr. A. Schott obtained a specimen on the Colorado River in Southern California, and Dr. Gambel and Dr. A. L. Heermann speak of it as common throughout that State, while Dr. Cooper and Dr. Suckley mention it as frequent both in Oregon and in Washington Territory. A single specimen was taken by Mr. Salvin in Guatemala. Dr. Cooper states that this Hawk is often killed about the farm-yards of Washington Territory, where it seizes on chickens before the very eyes of the owner, darting down like lightning, and disappearing again before he can see what has caused the disturbance. It is said to be a constant resident, and to breed within the Territory.

Mr. Audubon describes the flight of this Hawk as rapid, protracted, and even, and as performed at a short distance from the ground, or over the forest. It is said to move along in a silent gliding manner, and with a swiftness even superior to that of the Wild Pigeon, rarely deviating from a straight course except to seize its prey, and seldom mounting in the air in circles. It is very bold and daring, Mr. Audubon having known one to attack and kill a cock much larger and heavier than itself. It frequently attacks and kills the common Ruffed Grouse. It breeds in especial abundance in the Middle States, and particularly along the banks of the Potomac River. I have received reliable information of its nesting in Vermont, Massachusetts, Ohio, Illinois, Wisconsin, Maryland, Virginia, and South Carolina, and probably nearly all of the States. Mr. Gosse did not meet with it in Jamaica.

Mr. Audubon states that he found its nest usually placed in the forks of the branch of an oak-tree, towards its extremity. In general appearance it resembles that of the common Crow, being composed externally of numerous crooked sticks, and having a slight lining of grasses and a few feathers. The eggs he describes as three or four in number, almost globular, large for the size of the bird, of a dull white color, granulated and rough to the touch.

Dr. Hoy, in a communication to the Boston Natural History Society, mentions finding four nests of this Hawk in a single season, and his careful observations of the habits of the parent birds enabled him to ascertain that in each instance the birds began to sit constantly upon their nest as soon as a single egg had been deposited, and that, as a consequence, the eggs having been deposited at varying intervals, each one was found in a different stage of incubation from the other. In not a single instance did he visit a nest without finding the parent bird occupying it.

These nests were all composed of sticks, rudely lined with strips of bark and a few bunches of Usnea barbata. The nests were quite shallow and small for a Hawk. Most of the eggs were sparingly sprinkled with umber-brown. One set of these eggs was blotched with bluish-green, which soon faded out. While the nests were being molested, the parent Hawk would fly from tree to tree, uttering, in rapid succession, quick-quick-quick-quick.

Dr. Hoy states that the male of this species, during the nesting-season, may frequently be seen flying high in the air, sporting, vaulting, and turning somersaults on the wing, which habit has given to it the name of Tumbler-Hawk. No Hawk is harder to shoot, and none commits greater havoc among barn-yard fowls than this species. He has seen one strike a large hen while she was flying wildly for safety, and kill her on the spot, though it was obliged to abandon the game, as it proved too heavy to carry off.

I have specimens of its eggs from South Carolina, obtained by the young sons of Rev. M. A. Curtis, of Society Hill. Mr. Curtis, Sen., furnished me with the following description of its nest: “The nest of the Cooper’s Hawk was built in the triple fork of a tall black gum (Nyssa multiflora), near the top of the tree, which stood in a swamp. It was formed of a layer of small sticks, ⅓ to ½ inch in diameter. Its external diameter varied from 1½ to 2 feet. This layer was ⅞ of an inch in thickness, with only a slight depression in the centre, hardly enough to keep the eggs from rolling out. A few thin pieces of pine bark formed the bed for the eggs.”

Another nest, obtained in Randolph, Vt., by Charles S. Paine, Esq., is thus described by him: “The nest was built of hemlock twigs, and lined with small, thin pieces of hemlock bark, such as hang loosely on the tree. The Hawk, when the nest was approached, did not whistle, as some others of that family do, but uttered a cry of ge! ge! ge! ge! This was repeated several times, with great rapidity, by both male and female.”