National Museum, 44; Philadelphia Academy, 17; Boston Society, 1; Museum
Comparative Zoölogy, Cambridge, 10; Cab. G. N. Lawrence, 6; Coll. W. S.
Brewer, 3; R. Ridgway, 4. Total, 85.
_Measurements._
+----+-----------+-----------+---------+---------+-----------+----------+
|Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.|
+----+-----------+-----------+---------+---------+-----------+----------+
| ♂ |15.80–16.80| 9.80–10.00| .85–.90|2.75–2.80| 1.35–0.00| 18 |
+----+-----------+-----------+---------+---------+-----------+----------+
| ♀ |16.15–17.70| 9.00–10.50| .90–1.00|2.80–0.00| 1.30–1.40| 8 |
+----+-----------+-----------+---------+---------+-----------+----------+
| |15.75–18.00| 9.00–11.00| .80–1.00|2.15–3.00| 1.20–1.50| 40 |
+----+-----------+-----------+---------+---------+-----------+----------+
That all the North American Rough-legged Hawks, whether light or dark
(excepting of course the _A. ferrugineus_), are one species, and also
one race, there appears to be but little doubt; a critical comparison
and minute examination of about one hundred specimens also proves that
the dark plumage, usually separated as “_A. sancti-johannis_,” has
nothing to do with age, sex, season, or locality, but that, as in _Buteo
borealis_ var. _calurus_ and _B. swainsoni_, it is a purely individual
condition, black birds being black, and light birds being light, from
the first plumage till death. Each phase has its young and adult stages
distinctly marked, as the above diagnoses point out. It however appears
to be the fact that certain regions are frequented more by birds of one
color than another, and of the many hundreds of specimens sent from
the Arctic regions to the Smithsonian Institution by officers of the
Hudson’s Bay Company, none exhibited the blackish plumage which, on the
other hand, appears most abundant about Hudson’s Bay.
The North American birds are distinguishable from European ones (var.
_lagopus_) by the characters given in the synopsis on p. 1619, and
description, on p. 1624.
HABITS. The Rough-legged Hawk of North America bears so close a
resemblance to the European species, in all respects,—plumage, habits,
and eggs,—that the two are generally considered to be identical. The
distribution of the American variety appears to be nearly throughout
the entire Union, from the Atlantic to the coast of the Pacific, and
from New Mexico to the Arctic regions. It was taken at Fort Steilacoom,
and at Shoal-water Bay in Washington Territory, by Drs. Suckley and
Cooper. It was not seen by Mr. Dresser in Texas nor by Dr. Woodhouse in
New Mexico, but it was taken near Zuñi by Dr. Kennerly, was found from
Mimbres to the Rio Grande by Dr. Henry, and obtained near Fort Fillmore
by Captain Pope, and at Fort Massachusetts by Dr. Peters.
The Rough-legged Hawk is quite abundant in spring and fall in the
neighborhood of Niagara Falls. In the fall of 1872, Mr. James Booth met
with a pair of this species, accompanied by their young. The latter were
fully grown. The male bird was in very black plumage, while the female
was unusually light, the pair thus presenting well-marked illustrations
of the two types, the black _sancti-johannis_ and the common _lagopus_.
The parents were secured, and are now in the museum of the Boston
Society of Natural History. One of the young was also shot, but I did
not see it. It was said to have been only a little less dark plumaged
than the male parent.
It is very abundant throughout the Arctic regions, where it was found
breeding in the Anderson River country by Mr. MacFarlane, from whom were
received valuable notes and a large number of specimens of birds and
eggs. It was observed generally by Dr. Richardson’s party, but owing to
its extreme wariness only a single specimen was obtained. Richardson
noted its arrival in the fur countries in April or May, and gives the
time of its departure as early in October.
Dr. Kennerly mentions finding this Hawk quite abundant in the vicinity
of the Pueblo Zuñi, where it confined itself in the neighborhood of the
stream, watching eagerly for ducks, which seemed to be its favorite
prey.
[Illustration: _Archibuteo lagopus_ (Europe).]
Dr. Cooper found a large number of these Buzzards on a low point near
the sea-coasts, at Shoalwater Bay, Washington Territory, in October.
This point was covered with small pines, on the dead tops of which they
were observed sitting in the manner of owls. Occasionally one would
dart down after a mouse, and alight a short distance off. At times
they would call to each other with a loud scream, but they usually sat
motionless and silent for hours together. Some remained there throughout
the winter, and he had no doubt that a few build near the mouth of the
Columbia, where he saw young birds in July. In California, the same
writer states, this species is only a winter visitor, and has never been
observed by him south of Santa Clara Valley.
Dr. Coues mentions the taking of a single specimen of this bird in the
Territory of Arizona in the winter, but no others were observed.
Audubon never met with this species south of North Carolina nor west of
the Alleghanies. He regarded it as a sluggish bird, confining itself
to the meadows and low grounds bordering the rivers and salt marshes,
where its principal food appeared to be moles, mice, and other small
quadrupeds. He has never known it to attack a duck on the wing, although
it will occasionally pursue a wounded one. Except when alarmed, it
flies low and sedately, and manifests none of the daring courage or
vigor so conspicuous in most Hawks. They are also described as somewhat
crepuscular in habit, watching for their food long after sunset, and
Mr. Richardson speaks of their hunting for their prey “by the subdued
daylight which illuminates even the midnight hours in the high parallels
of latitude.” For these nocturnal hunts it is well fitted by the
softness of its plumage, which renders its flight noiseless, like that
of the more nocturnal birds.
These birds were once quite abundant in the low lands and marshes in the
vicinity of Boston, but are now comparatively rare. They were abundant
during October and November, and again in April. They usually kept
on or near the ground, appeared to feed chiefly on small quadrupeds
or reptiles, were never known to molest the poultry-yard, or even to
destroy other birds.
[Illustration: _Archibuteo sancti-johannis_ (black plumage).]
They were very wary, and when approached with a gun would slowly and
deliberately move off to a safer distance. Wilson found them quite
abundant, during the winter months, in the meadows on the Delaware and
Schuylkill Rivers, near Philadelphia, where they are still common.
Though rendered very shy by the frequent attempts made to shoot them,
they would never fly far at a time, usually from one tree to another,
making a loud squealing noise as they arose. They all disappeared early
in April.
He also speaks of them as common during winter in the lower parts of
Maryland, as well as in the extensive meadows below Newark, N. J. He
mentions having often seen this Hawk coursing over the surface of
meadows long after sunset, and many times in pairs. They roost near
these low grounds, and take their station at daybreak near a ditch,
watching with patient vigilance for their prey.
Wilson, Audubon, and Nuttall appear to have known nothing in regard to
the breeding of the Rough-legged Hawk. A pair was seen by Richardson at
their nest, which was built of sticks, and on a lofty tree standing on
a low moist alluvial point of land, in a bend of the Saskatchewan; but
they were too wary to be shot, and he makes no mention of their eggs.
My nephews, H. R. and F. H. Storer, found a pair of Rough-legged Hawks
nesting on a rocky cliff on the coast of Labrador, near the harbor of
Bras d’Or. The nest was very rudely constructed of sticks, and placed
on a high rock directly over the water, inaccessible from below, but
readily approached from above. It contained three young birds and an
egg. The young Hawks were just ready to fly, and all scrambled out
as the nest was approached, and rolled the egg to the bottom of the
cliff, but without injuring it. The nest contained four or five large
rats peculiar to that region, collected by the old birds for their
young. The old birds were in the light plumage. At the same time a young
bird was taken alive from another nest by one of the sailors of their
party, which was quite black even in its immature dress, and strikingly
different from the young just mentioned.
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.
The eggs from New Jersey, attributed to this bird by Mr. Krider, vary
in the number and depth of coloring of their markings, the blotches in
one being darker and less generally distributed. They measure 2.06 by
1.69 inches. Their ground-color is a yellowish white, intermingled with
which are faint markings and blotches of a brownish-purple. Over these
are diffused confluent blotches of russet-brown.
An egg from near Wiscasset, taken by Edmund Smith, Esq., the parent of
which was secured, measures 2.22 by 1.75 inches, has a white ground, and
is marked and blotched with deep umber-brown. These markings are chiefly
at one end and only vary in their depth, and are unmixed with any other
shading or colors.