National Museum, 22; Boston Society, 2; Museum, Cambridge, 2; Cab. G. N.
Lawrence, 2; Philadelphia Academy, 2; Coll. R. Ridgway, 2. Total, 32.
_Measurements._
+----+-----------+-----------+---------+---------+-----------+----------+
|Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.|
+----+-----------+-----------+---------+---------+-----------+----------+
| ♂ | 8.50–9.85| 7.50–9.20| .60–.70|2.10–2.75| 1.30–1.65| 24 |
+----+-----------+-----------+---------+---------+-----------+----------+
| ♀ |10.20–10.60| 9.30–10.50| .70–.75|2.65–2.75| 1.65–1.75| 4 |
+----+-----------+-----------+---------+---------+-----------+----------+
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.
[Illustration: _Nisus cooperi._]
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.”
The average size of the eggs of this bird is 1.56 by 1.94 inches. The
color is usually a uniform dull white, but is occasionally tinged with
as light bluish shade. They are nearly spherical, though not more so
than the eggs of several species, and are equal at either end. Their
surface is slightly granulated. The number of the eggs varies from three
to four, though occasionally there are five in a nest.
The maximum length of the egg of this species is 2.00 inches, the
minimum 1.85; the maximum breadth 1.60, the minimum 1.50 inches. In
occasional instances I have known the eggs of this species more or less
distinctly marked, especially about the larger end, with blotches of a
light yellowish-brown. Those most distinctly marked in this manner were
taken and identified by Mr. Paine.
A nest of this Hawk, found by Dr. J. W. Velie, was built on a
poplar-tree, about forty feet from the ground, and was composed of
sticks and lined with moss and leaves. There was a small cleared space
of three or four rods in extent, in the middle of which the tree stood,
and about a quarter of a mile from the main channel of the Mississippi
River, on Rock Island.
The Cooper Hawk was found on Mount Tom by Mr. William Street, nesting
for the most part in pine or hemlock trees, usually choosing one in
a thick clump. They begin to lay about the first of May, usually
depositing four eggs. They are very shy, and it is almost impossible to
get within shot of them, even when they have young. They rarely molest
the poultry-yard, but seem to live chiefly on small birds and animals.
They leave their nest at once whenever it is approached, and will not
return until the intruder has gone.
The var. _mexicanus_, originally described by Mr. Swainson from Mexican
specimens obtained near Real del Monte, has been ascertained to cross
our boundaries, and is found in all the territory between the Rocky
Mountains and the Pacific, as far north as Washington Territory. Dr.
Cooper has never met with this Hawk, but supposes its general habits,
and especially those regulating its migrations, closely resemble those
of _A. cooperi_, to which the bird itself, in all but size, is so
similar. Dr. Coues speaks of it as a common resident species in Arizona.
He states that he has seen young birds of this species, reared by the
hand from the nest, become so thoroughly domesticated as to come to
their master on being whistled for, and perch on his shoulder, or follow
him when shooting small birds for their food. They were allowed their
entire liberty. Their ordinary note was a shrill and harsh scream. A
low, plaintive, lisping whistle was indicative of hunger.
Dr. Suckley, who met with this bird on Puget Sound, where a specimen was
shot on a salt marsh, states that, while soaring about, it resembled in
its motions the common Marsh Hawk, or Hen Harrier (_Circus hudsonius_).