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Northern
Harrier
Circus cyaneus [Marsh Hawk]
[Published
in 1937: Smithsonian Institution United States National Museum
Bulletin 167 (Part 1): 78-95]
The above name [Marsh Hawk] recalls to mind those delightful
days, now long past, when we sat for hours in a flimsy blind on
the Cape Cod marshes, listening for the startling whistle of the
yellowlegs or the mellow notes of the plover. The day is one of
those lovely Indian summer days; only a gentle breeze is stirring,
and the autumn haze softens the brilliant colors with which the
waning summer has painted the marsh vegetation and the distant
woods. As we sit there in the soft sunshine, dreamily drinking in
the beauties of the scene, our eyes are alert to what is going on
around us. Off on the distant mud flats are flocks of gray and
white gulls, with scattered groups of shorebirds; over the
extensive salt marshes black terns are winnowing the air, or
plunging down into the grass for grasshoppers, and numerous
swallows, now nearly ready to migrate, are skimming low over the
meadows or the little pools; on a nearby sand flat some turnstones
are digging holes in the sand; occasionally a great blue heron or
a bittern flaps lazily over the marsh. There is always something
moving; and, whether the yellowlegs and plover come to our decoys
or not, we are sure to see, sooner or later, a dark speck in the
distance that soon develops into a large, long-tailed, long-winged
bird. On it comes with an easy gliding flight, its long wings
slanting upward; as it turns we see its brownish breast and then
its white rump, a young marsh hawk. A lazy, loafing, desultory
flight it seems, but really it is full of purpose, as it quarters
low over the ground in a systematic search for its prey. Often
during the day it circles near us, but not too near, for all hawks
have learned to avoid gunners. A peaceful day on the marshes would
hardly be complete without an occasional glimpse of this
industrious harrier, to add its touch of life to the picture.
But the marsh hawk's haunts are not limited to marshes. It is
very common on the prairies and plains of the Middle West, though
it shows a preference for the vicinity of sloughs and wet meadows.
M. P. Skinner tells me that in Yellowstone National Park he sees
"more of these hawks hunting over the rolling upland prairies
than anywhere else." Here they "choose both the grassy
meadows and the sage-and brush-covered hills to hunt over."
He has even seen them "hunting across the open lands high up
on the mountains," between 5,300 and 10,300 feet. Anywhere in
open country, where prey may be found, the marsh hawk is likely to
be seen.
Spring.--The marsh hawk is a
migratory species. Most individuals spend the winter in the
Southern States or in the milder sections of the country. But,
even as far north as Manitoba, C. L. Broley tells me he has seen
the species every month but January. There the light-colored males
are the first to arrive, around the middle of March, and the brown
females come about three weeks later. The season is about the same
in southern New England, where some birds remain all winter near
the coast.
Courtship.--Many accounts of the
spectacular nuptial flight have appeared in print, but I prefer to
use the following description of it, one of the best, in some
notes sent to me by Mr. Broley:
This is a vigorous and pleasing series of nose dives, mostly
done by the male, although the female frequently takes part in
them. This takes place sometimes at an altitude of 500 feet, but
the usual flight averages 60 feet up, swooping down to 10 feet
from the ground. It might be illustrated by placing a number of
capital U's
together as UUUUUUUUUUUUUUUUUU,
as the turn at the bottom is well rounded out, but at the apex the
bird almost stalls, tipping downward again to continue the
movement. Some observers claim it makes a somersault as it turns,
but only on one occasion have I seen any indication of this. The
wings are kept fully extended during the whole period, and they
appear to be working easily all the time. I have seen a male make
71 of these dips in succession, fly on for a short distance, and
commence anew. The average number of dips would be perhaps 25. The
flight is frequently made while the female is flying along near
the ground hunting for mice, below the male, or again he may swoop
continually in one location while she is standing on the ground.
The movement is extremely graceful and is a welcome sight each
spring.
Other observers have described a similar performance, which
seems to be characteristic of the species, but most of them have
noted a complete somersault, or a sidewise turn, at the top of the
rise. E. H. Forbush (1927) says: "As it bounds up and down in
the air, it seems to move more like a rubber ball than a bird. . .
. When two of these birds are mated or mating they keep together
much of the time, either on the ground or in the air. When the
female alights the male follows her and walks or flies around her.
On the ground he bows to her and swells with amorous ardor.
Sometimes the male flies alone across the marsh rising and falling
alternately and with each fall turning a complete somersault, as
if to show his larger mate what a clever and wonderful bird he
really is. Again he 'carries on' in the same way while flying in
her company."
Nesting.--In southeastern
Massachusetts, at least in the region I hunt over, the marsh hawk
is a rare breeder. My first nest was found in a sphagnum bog,
overgrown with low huckleberries, pitcher plants, and scattered
small larches, and surrounded with thickets of alder and swamp
honeysuckle, a secluded spot. The nest was a flimsy structure of
light, dry sticks and straws, loosely placed on the flattened tops
of the low huckleberry bushes, only a few inches above the water
and the thick growth of sphagnum moss and pitcher plants. It held
five eggs on April 30, the last two having been laid during the
past three days, indicating that the eggs may be laid on
successive days.
Another and better nest was found in a somewhat different
swamp; it was densely overgrown with alders, swamp azaleas,
huckleberries, and other bushes, in some places higher than my
head and difficult to penetrate, but in the center was a more open
space, where the bushes were lower and more scattered, with a few
brakes and flags growing up among them. Here the nest was placed
on slightly elevated ground among some small bushes and brakes. It
was a handsome and well-made nest of dry straws, weed stems, and
sticks and lined with finer straws, brake stems, and thistle
tops; it measured about 23 by 20 inches in outside and 9 by 8
inches in inside diameter; the material in the center of the nest
was about 2 inches deep. It held five spotted eggs on May 26.
But our local birds do not always nest in swamps. We have found
them nesting on high and dry ground in what we call sprout lands,
where woods have been cut off and where sprouts are growing on the
stumps, but usually near a swamp or meadow. In such a place a
similar nest to those described above is built on the dry ground
and the larger stumps are used as perches or feeding stations.
Other observers have described nesting sites at various eastern
points.
Charles A. Urner (1925) made a careful study of three nests on
the salt marshes of New Jersey, of which he says:
One nest was found in the center of a large clump of
High-tide Bush (Iva oraria), and two were even more
securely hidden in large beds of thick reeds (Phragmites
communis). One was on dry, sandy ground, the other two on the
wet marsh, occasionally flooded by tide.
Here I found an interesting difference indicating that the
Harrier varies the height of its nest with the danger of floods in
its chosen location. A nest found on dry ground, above all tide
levels, constructed of weed stalks and grasses, nicely lined, was
only an inch or two thick. A nest located on the marsh over a mile
inland from the shore of Newark Bay, but more or less exposed to
floods and unusual tides, was similarly constructed, but was about
5 or 6 inches thick. A third nest, found nearer the Bay shore and
in a location frequently flooded, was remarkable for its greater
size and bulk. It was built of weed stalks and finer material to a
height of fifteen to eighteen inches, and it measured over three
feet long and two feet wide. It was of uniform construction from
the ground up with no indication of a "foreign"
foundation.
In more western States the marsh hawk sometimes nests in bushy
swamps or in brush-covered slopes, or even hillsides, but more
commonly it selects more open grassy situations, the margins of
sloughs, wet grassy hollows, or even extremely wet situations
among reeds, flags, or tules. In Nelson County, N. Dak., we found
five nests in one day, June 3, 1901. One was well made of sticks
and straws and lined with soft grasses; it was built up 14 inches
above the water in a patch of dead flags on the edge of a slough;
it contained two young hawks, three normal eggs, one runt egg, and
a dead spermophile. Another still finer nest, made of sticks,
reeds, and coarse weeds, was built up 18 inches above the water in
a wet meadow and measured 30 inches across the top. Other nests
were similarly located.
Dr. John W. Sugden writes to me that in Salt Lake County, Utah,
on July 18, 1928, he found a nest, containing five half-incubated
eggs, "near the center of a 30-acre wheat field on a dry
farm, at least 4 miles from the nearest water. The nest was a
shallow depression in the ground lined with a few sticks and
straws." Bendire (1892) mentions a nest found by George G.
Cantwell on a haycock.
Both birds assist in building the nest, the male bringing some
of the material and dropping it for his mate to arrange, but most
of the gathering and arranging of material is done by the female.
E. L. Sumner, Jr., watched a female building her nest and has sent
me his notes on it. He saw her make seven trips to the nest within
10 minutes. He says:
In carrying the sticks, if they are small, she nearly always
uses her bill alone; if they are large she uses her feet; in one
case of a particularly large branching stalk she carried it in
beak plus both claws; in another case she transferred a piece from
her beak to her claws while sailing toward the nest. Once she
carried a particularly large weed in her feet, but all the other
times she used her bill instead. Once she picked up a piece,
started to fly with it, but stopped and picked up another piece in
addition, but in flying away with them, dropped the first one and
then the other so that she had to continue on across the rush
patch to the other side and pick up another load. Once I saw her
tug violently at a weed that was still rooted, but it did not give
way, and so she walked a few steps farther on and picked up a
loose piece instead.
W. H. Laine (1928) reports finding a marsh hawk incubating on a
nest of 12 prairie chicken eggs; the experiment was not a success,
as only one chick hatched and it promptly ran away. Perhaps the
hawk's nest had been destroyed and she adopted the nearest
available nest.
Eggs.--Perhaps the commonest number
of eggs is five, but four or six are frequently found and
occasionally as many as seven or eight, or even nine, are seen in
a marsh hawk's nest. In shape they are ovate, short-ovate, or
nearly oval. The shell is smooth, with little or no gloss. The
color is dull white or very pale bluish white. They are generally
unmarked, but about 10 percent of the sets show, more or less,
scattered spots of very pale browns, "cinnamon-buff" or
paler, dull buff.
The measurements of 84 eggs average 46.6 by 36.4 millimeters;
the eggs showing the four extremes measure 53 by 38, 48 by 39.5,
41.4 by 35.6, and 43 by 34 millimeters.
Young.--The period of incubation
has been variously estimated as 21 to 31 days; the latter figure
was definitely noted by Aretas A. Saunders (1913). It is difficult
to determine, as it often begins when the first egg is laid; an
egg is usually laid each day, but often a day or two may intervene
between layings. Both sexes share the duties of incubation and
care of the young, and they are very devoted parents. Mrs. Irene
G. Wheelock (1904) writes:
In eighteen to twenty days the young Hawks break their hard
shells, one each day, and cuddle down among the feathers and straw
of the crude nest. From the day the first little ball of down
appears, one or the other of the adults may be seen constantly on
the wing over that meadow. The same tactics are pursued as before,
for the food is dropped to the parent on the nest, who, after the
first few days, holds it fast in her beak while the nestlings tear
off bits from it for themselves. In this way the muscles of
the bill and neck are developed. Later on the food is simply
dropped to them, both parents being off on the hunt, and the
little fellows grasp it in their sharp claws and tear from it with
a right good-will.
Aretas A. Saunders (1913) noted that three eggs in a set of
five hatched between the evening of June 30 and the morning of
July 1. The fourth bird hatched before the morning of July 2, the
fifth on the afternoon of July 4, and the sixth on July 7. He
noted that they were born with their eyes closed, but that they
opened within a few hours. Following is his account of their
development:
For the first six or seven days the young showed no change
in appearance except that they grew larger and became somewhat
more active. On July 8, just after the youngest bird had hatched,
I noted that the oldest birds were about three times the size of
the youngest. About July 10 the two youngest birds disappeared,
probably having died. I believed that this was because they were
so much smaller and weaker than the four older birds that they
were unable to get their proper share of food.
Sheathed feathers began to appear in the oldest birds at the
tips of the wings on July 8, when they were seven days old. On
July 14, when twelve and thirteen days old, the birds began
showing fear and crawled back into the cinquefoil bushes when I
approached. When I attempted to handle them, they sat up and
threatened me with their beaks, and called in a high, squeaky,
baby voice. On July 17 the feathers at the tips of the wings began
to break the sheaths, and sheathed feathers were appearing thickly
on back, shoulders, breast and tail. At this time the feet and
cere were beginning to turn from a light pinkish color to yellow.
On July 22 the feathers were breaking the sheaths in many places,
those at the tips of the wings being broken for about two inches
of their length. The feet and cere were now bright yellow. The
birds stood with outstretched wings and open beak, turning to face
me no matter to which side of the nest I went. They were in about
the same condition on July 24, so that I found it almost
impossible to handle them. When I attempted to photograph them
they crawled off into the bushes so that I could only get two at a
time in the picture.
During the week following this the birds changed rapidly.
Feathers unsheathed all over them, and much of the white down came
off. On August 4, when the birds were thirty-three and thirty-four
days old, I approached the nest and found three of them able to
fly a little. One rose at my approach and flapped away for about
150 feet before it sank in the grass.
Mr. Urner (1925) found that the time from hatching to flight
was about 30 to 35 days. He refers to them as "sturdy,
fearless, wide awake, active, noisy and hungry youngsters. . . .
The readiness with which the young imitate their parents is worthy
of note. On July 7, I visited a brood which had left the nest and
learned to fly, though still in the vicinity of the nesting site.
They flew in all directions as I approached, uttering an immature
peeping call. The adult male turned immediately to attack and I
was surprised to see two of the young, probably males, follow
suit, flying in very close and making a more or less unsuccessful
effort to imitate the long rolling call."
As to the food of the young he says:
As far as I can judge from remains picked up in the general
vicinity of the nests, mice and small birds, supplemented with
insects, constitute the principal fare during early life. But as
the birds grow, rats assume a more important role, and in or near
two different nests I found remains, picked clean, of practically
full-grown American Bitterns (Botaurus lentiginosus). Now
the young American Bittern is no mean antagonist, and the fact
that such large birds are actually killed and carried to the nest
indicates the calibre of the Harrier as a hunter. . . . During the
fourth week of the young Harrier's life pellets of fur and
feathers, containing some bone, begin to appear about the nest.
These pellets are often as large, as compact and as well formed,
as those of the Short-eared Owls, constituting an interesting
similarity between the two species. It is probable that the
failure to find pellets about the nests earlier in the young
brood's growth is due to the thorough removal of waste by the
adults, rather than any change in feeding habits.
The main reason why pellets are not found about the nest during
the early life of the young is that the old bird feeds the young,
at that age, with small pieces of pure flesh. Dr. Frank N. Wilson
(1927) saw, at close range, a marsh hawk feed a field mouse to her
small young. "Holding it in her beak, she walked to the edge
of the nest and, placing both feet upon it, tore off small pieces
of the raw flesh and fed the young in turn. The coarser parts she
ate herself."
After the young are able to fly they are often fed by their
parents while on the wing. Dr. Charles W. Townsend (1905) writes:
"Three weeks later near the same place, the female flew over
my head, and whistled as she approached the nesting site. Upon
this, four full grown young Hawks flew up to meet her and she
dropped from her talons a mouse, which after falling about five
feet was skillfully caught in the air by one of the youngsters.
How it was done, whether in the bill or in the talons, I could not
make out in the confusion. It certainly did not get by the birds,
who at once retired to the ground, the successful one to eat its
prize."
For a long time after the young are able to fly, the family
group hangs together, hunting over the familiar grounds near their
former home, the young learning from their parents and practicing
the serious business of earning a living.
When the time comes for migrating, young birds are apt to
wander widely in different directions. Young birds banded as
nestlings by William I. Lyon, at Waukegan, Ill., were recovered
that season, one at 50 and one at 300 miles northwest, and another
at 500 miles southwest.
Plumages.--When first hatched the
chick is covered with short down, very scanty on the under parts;
it is pure white with only a short tinge of buffy on the upper
parts. As the chick grows, the down increases in length and
becomes darker, "pinkish buff," on the upper parts; the
lores and a space around the eyes are naked. The development of
the juvenal plumage is described by Mr. Saunders (1913) above. In
fresh juvenal plumage, in August, the upper parts are "mummy
brown," many feathers narrowly tipped, or broadly margined,
or deeply notched, with "tawny" or "cinnamon";
the white upper tail coverts are tinged with "cinnamon";
the tail has four dark "mummy brown" bands, the four
intervening bands being dark gray on the central pair of feathers
and much mixed with "tawny," "cinnamon," gray,
and white on the other feathers; the primaries are brownish black
above, glaucous on the outer webs; the entire under parts are rich
yellowish brown, "amber brown" to "ochraceous-tawny,"
broadly streaked on the chest and narrowly on the flanks with
"bister," but otherwise immaculate. The sexes are alike
in plumage, but there is a marked difference in size.
The juvenal plumage is worn for about a year but becomes much
faded by spring; young males fade out to almost white below.
Molting sometimes begins in April but usually not until summer,
when a complete molt takes place from July to October or later.
This produces a second winter plumage in which the sexes are
different. Young males are quite dark above, "bister" to
"mummy brown"' the under parts are largely white, with
considerable drab and buffy mottling, especially on the chest,
which is heavily clouded with drab; the wings and tail are much
like those of the adult. Young females show similar progress
toward maturing, but they still show many rufous edgings above;
they can be distinguished from first-year females by their spotted
breasts. At the next complete molt, the following summer, the
young become practically adult in plumage, though probably males
continue to grow whiter as they grow older. Adults have their
complete annual molt during July, August, and September.
Food.--The marsh hawk is regarded by
many as a highly beneficial species, mainly because of the large
numbers of mice, rats, and other injurious small mammals that it
destroys. It certainly is a great mouser; it lives largely on
frogs and small snakes and devours many injurious insects, but the
records show that many small birds and some larger ones are killed
by it. Dr. A. K. Fisher (1893) gives the following summary of its
food:
Of 124 stomachs examined, 7 contained poultry or game birds;
34, other birds; 57, mice; 22, other mammals; 7, reptiles; 2,
frogs, 14, insects; 1 indeterminate matter, and 8 were empty.
Although this hawk occasionally carries off poultry and game
birds, its economic value as a destroyer of mammal pests is so
great that its slight irregularities should be pardoned.
Unfortunately, however, the farmer and sportsman shoot it down at
sight, regardless or ignorant of the fact that it preserves an
immense quantity of grain, thousands of fruit trees, and
innumerable nests of game birds by destroying the vermin which eat
the grain, girdle the trees, and devour the eggs and young of the
birds.
Maj. Allan Brooks (1928) condemns the marsh hawk, as "the
most destructive hawk in all America to our marsh loving waterfowl
for at least three months in the year." He accuses it of
killing large numbers of young ducks and says that it does not
kill its victim outright "but slowly wears the wretched
captive out and literally eats it alive commencing at the breast
muscles." He cites another case where a family of marsh hawks
killed over two dozen old and young blue and ruffed grouse during
one nesting season. These cases are probably exceptional, or
extremely local in effect, for most of the evidence is in favor of
the marsh hawk. Herbert L. Stoddard (1931) found remains of cotton
rats, which destroy the eggs of quail, in 925 out of 1,100 pellets
of this hawk. Several observers have mentioned the great service
that marsh hawks perform in the southern rice fields by driving
away bobolinks and blackbirds more effectively than hired men with
guns, thus saving considerable expense.
Meadow mice seem to constitute the bulk of the food, according
to nearly all observers. Judge John N. Clark wrote to Major
Bendire (1892): "One I examined contained not less than
eleven, another nine, and nothing else." Among other mammals
taken are young rabbits, young skunks, pocket gophers, rats,
spermophiles, squirrels, shrews, and moles. The long list of birds
includes bittern, green heron, teal and other ducks, coot, rails,
grouse, quail, partridges, pheasants, plovers, sandpipers,
woodcock, snipe, sparrow hawk, screech owl, flicker, doves,
starling, meadowlark, blackbirds, grackles, numerous sparrows,
cardinal, towhees, warblers, wrens, mockingbird, catbird,
thrashers, robin, bluebird, and thrushes. Frogs form a large item;
and small snakes and lizards are eaten. It also feeds on large
numbers of grasshoppers, locusts, crickets, and other insects.
Ivan R. Tomkins tells me that in the saltwater marshes of South
Carolina and Georgia "its winter food is mostly marsh rabbits
(Sylvilagus palustris)." At times it is quite
destructive to poultry and game. E. S. Cameron (1907) writes:
"This bird is the common 'Henhawk' of eastern Montana and is
the most pertinacious of any in attacks on the poultry yard. Young
marsh hawks weighing about ten ounces will endeavor to disable a
chicken weighing a pound, by pecking it on the head and striking
on the back at the same time with the feet, their strong wings
enabling them to keep directly above it no matter where the prey
may run. Birds of the year, through inexperience, are the most
daring, and my wife has taken a screaming pullet from the claws of
one of them which found the prize too heavy to lift."
Henry K. Coale (1925) reported that a marsh hawk killed 7 of a
flock of 14 Hungarian partridges within two weeks, before it was
caught in a trap. "It would tear the back open and rip the
flesh and skin off in strips."
The well-known habit of quartering the ground over fields or
marshes, barely high enough to clear the tallest vegetation, is
the common method employed to hunt its principal prey, small
mammals and small birds. Its keen eyes are quick to detect its
quarry, and its flight is under such perfect control that it can
stop suddenly and drop quickly down upon the victim. Usually it is
devoured right there on the ground, but often it is carried to
some convenient stump or post, or carried away to feed its mate or
young. A mouse or small bird may be almost wholly eaten, but a
larger animal or bird will be skinned or plucked and the flesh
torn off. When the victim is too large to be eaten at one meal,
the hawk may return later to finish the feast. Dead game or even
carrion is often welcome. A. G. Lawrence writes to me: "E.
Robinson informs me that he has seen marsh hawks hovering in front
of a prairie fire, picking up the mice as they fled before the
flames. I have seen a marsh hawk hover for more than 5 minutes
over a bush in which a small bird had taken refuge, darting
rapidly from side to side when the bird ventured to fly out, but
mainly hovering over the bush about 10 feet up. Eventually it
swept down beyond the bush and secured its victim as it tried to
escape."
Several observers have noted the interesting way in which the
male feeds his mate. C. L. Broley has sent me the following note
on it: "The male flies with the mouse near where the female
may be nesting and calls to her; upon which she takes to the air;
and, flying 12 to 20 feet over his mate, the male drops the mouse.
The female either turns partly on her back and catches the mouse
with her claws or, as on one occasion, just swings her feet
out to the side and catches the mouse neatly. I have seen the male
carry a mouse 15 minutes awaiting the return of his mate to
present it to her. Another time the male became tired of waiting
for her and ate half the mouse but kept the other half till she
returned."
Eugene S. Rolfe (1897) noted the following interesting attempt
to secure a meal: "Many times I have watched the Marsh Hawk
sailing low and keenly scanning the ground on the open prairie,
and suddenly pouncing down and quickly ascending again with an
empty mouse nest in its talons, and one one occasion I followed
behind for fully 2 miles and in that distance it picked up and
dropped seven of these empty nets. On examination they proved to
be simply wads of fine dried grasses, and it was easy to see that
if these had all chanced to be occupied by families of young mice,
the foray of that particular Hawk would have been most fruitful in
the destruction of these small pests."
E. L. Sumner, Jr. (1931) witnessed a playful reaction of a
marsh hawk with a horned lark that it had captured:
All at once the hawk dropped the lark, whereupon the latter,
still alive flew weakly to the ground about seven feet away, its
captor with outstretched talons hovering meanwhile about two and
one-half feet above it but not pouncing upon it. When the lark
reached the ground, the hawk lit beside it, then gave a little
jump into the air and landed with spread talons upon its prey. It
seemed not to bite the lark, but after examining it with many
twistings and turnings of the head rose about three feet into the
air with it, and then dropped it again, the lark still fluttering,
and pounced upon it just as before. This the marsh hawk did seven
or eight times, and I marveled at the clumsiness of the bird until
I realized what was going on--it was playing.
At length the lark fluttered into a tangle of shrubby weeds,
which circumstance seemed to furnish even more interest for the
hawk. It would prance about in the weeds, taking great high steps,
and now and again bend down to peer intently in at the lark. I do
not think the hawk at any time really lost its prey. This
continued for about ten minutes from the time when I had started
to watch, after which the bird settled in a little depression with
its victim and was then out of sight.
Behavior.--Much of this subject
has already been covered under other headings. The characteristic
low flight, as it quarters over the wide open spaces in search of
food, is light, buoyant, graceful, and easy, as well as long
protracted and apparently tireless. William Brewster (1925) has
described it perfectly, as follows: "Flying ever in the
buoyant, unhurried manner so characteristic of their race, now
renewing waning impetus by a few deliberate wing strokes, next
gliding for several rods on wings set with the tips held well
upwards, much as those of a gliding Turkey Vulture are held,
tilting their bodies more or less perceptibly from side to side
and rarely pursuing a perfectly straight course for more than a
few yards at a time, they may skirt the shore for miles, following
all its windings closely, and keeping just outside the outer ranks
of living trees, but taking no especial pains to thus avoid
outstanding dead ones."
While migrating it flies at a higher elevation with steadier
wing beats. Its nuptial flight is spectacular and shows its
ability as an aviator and a stunt flier, for which the long wings
and tail, combined with a light body, are well adapted. Its lofty
evolutions are not so well known, but it compares favorably with
other hawks in its soaring ability. Mrs. Bailey (1915) says:
"When flying high enough to be exposed to the strong prairie
wind, her maneuvers, and those of the male when he joined her,
were fascinating and beautiful to watch. After flapping low over
the ground, they would set their wings and, perfected monoplanes,
rise with the wind, tilting and turning, changing their angles
with enviable skill to meet the vagaries of the air currents. They
would sail with set wings, buffeted by the wind, and then, as if
their sailing muscles were tired, turn tail in midair and sweep
back with a beautiful downward curve."
Marsh hawks occasionally perch on trees or bushes, but only
rarely; they normally stand on the ground or perch on stumps,
fence posts, or telegraph poles. They even roost on the ground at
night. They have favorite perching, feeding, and roosting
stations, which are well marked with pellets, excrement, and
feathers. Mr. Stoddard (1931) says: "This species has the un-hawklike
habit of roosting on the ground, frequenting the same spot night
after night. If numerous, these hawks form a loose roosting group
numbering from two or three, to as many as thirty. A large field
grown up to heavy broom sedge and preferably upon a hilltop is
chosen as a roosting site. Each bird has a beaten down spot in the
sedge, well 'limed' with the droppings."
J. D. Smith shot a male marsh hawk just after daybreak of a
very frosty morning; its back and tail feathers were covered with
frost.
I have no brief for the marsh hawk as a gentle, harmless bird;
on the other hand, I consider it a decidedly intolerant,
aggressive, and pugnacious defender of its home territory, as
everyone knows who has ever attempted to invade its precincts.
Especially when there are young in the nest, or even after the
young are on the wing, one or both parents are sure to attack the
intruder. Some say that the male is more aggressive, but I have
seen very little difference. I have had them dash at my head
repeatedly, and keep it up as long as I was anywhere near the
nest; flying off for a short distance, the hawk would turn and
come like a flash straight for my face, as if it would surely
strike me; but it always just missed me by a few inches. A. D.
DuBois writes me: "While I stood near a nest, trying to
arrange a tripod and camera, the parent marsh hawk repeatedly
struck me on the head. In one of these onslaughts she lifted my
hat and dropped it on the ground. Her claws penetrated the hat
sufficiently to scratch the scalp."
Mr. Saunders (1913) had a marsh hawk attack him frequently when
he was a long way from the nest and often not headed in that
direction, once when he was a mile away from it. Mrs. Bailey
(1915) had similar experiences. Elon H. Eaton (1910) had the
bellows of his camera, which he had concealed near the nest, torn
to pieces by the attacking hawk. Paul L. Errington (1930) gives an
interesting account of the territory disputes of three pairs that
nested within 400 yards of each other; each pair had its
definitely outlined territory, on which none of the others were
allowed to trespass.
No less intolerant is their behavior toward other species. They
have been seen repeatedly attacking red-tailed and red-shouldered
hawks that were peacefully soaring over their domains. They always
drive away crows and have been known to attack and drive away
eagles. They often drive away sparrow hawks, blackbirds, and other
small birds without attempting to catch them. Walter B. Savary
writes to me that he "saw a marsh hawk with a mouse in its
claws trying to escape from three crows that were pursuing it in
an endeavor to get the mouse. So close at last were the crows that
the hawk let its prey drop; without checking its flight, the
leading crow snatched up the mouse and continued on, to be at once
followed by a caracara, which, in turn, forced the crow to drop
its prize. This happened so near me that the hawk dared not to
pick up the mouse, but perched on a nearby stub and waited."
Even the bold and dashing duck hawk is sometimes robbed of its
prey, but sometimes the tables are turned. Forbush (1927) relates
a story, told him by William G. Means, of a duck hawk that knocked
a marsh hawk off a fallen duck it was eating. On the other hand,
C. J. Maynard (1896) writes: "The Marsh Hawks are, as a rule,
not very bold but I once knew an exception to this and, while in
Florida, some years ago, repeatedly saw one of these birds rob a
Peregrine Falcon of Ducks which it had captured. This appears
almost incredible, but I was once quite near when the Marsh Hawk
took possession of the booty of the Falcon that was sitting on the
ground, and I distinctly saw the latter give up his prey, almost
without a struggle, to the venturesome Hawk which coolly began to
eat it, utterly disregarding the screams of the Falcon that was
darting about a few yards above him."
I have often noticed, in a large colony of breeding terns, that
as soon as a marsh hawk appears on the scene their otherwise
ceaseless din suddenly stops, every voice is still; the silence is
so striking that we look up to see the cause, as thousands of
white wings are diving after him in an angry mob, and he is forced
to beat an hasty retreat. I have no evidence that the hawk ever
molests the terns. I have seen the same phenomenon in a densely
populated colony of yellow-headed blackbirds in a western slough.
Lewis O. Shelley (1930) enjoyed an unusual experience in taming
some young marsh hawks that he raised from the nest, of which he
writes:
They flew anywhere they wished and were always called by a
whistling note. They flew all about the village and to points a
mile or more distant at least, without harm by humans befalling
them. Their maneuvers were at once interesting and unbelievable at
the same time to everybody, including myself. That they became
perfectly tame and came to me when called, was a reaction
considered remarkable in a wild raptorial bird. . . .
During the fall migration, vireos, warblers, sparrows--many
species--would feed contentedly in the same tree, on the same
limb, with one of the hawks. I never saw an attempt of the hawks
to molest them. Our own and the neighboring hens became used to
the hawks and did not become frightened when they alighted in the
hen yards. . . .
At any time when I wanted them to exhibit to visitors or for
other reasons, if within hearing distance they always came. If I
merely whistled to answer their common "contented" call
they took it for what it meant and remained where they were, often
shifting their positions to be able to watch me. A sharp whistle
served as "mess-call" and was responded to
promptly--quite so. Perhaps the greatest thrill was in having them
alight on my person, anywhere, at any time; to be able to handle
them to my utmost content without fear of injury; to call them
when I left work at the store and have them fly home with me for
the evening meal. . . .
As to sight and hearing, their instincts were unsurpassed.
Any noise, and a good many too slight to be detected by human
ears, was noted instantly with whatever reaction suited the case
at hand. To illustrate the eyesight: I once held an inch cube of
meat in my finger tips over my head, uttering no sound. A hawk
perched in a tree about one hundred and fifty yards distant
immediately rushed to me, eyes upon the tid-bit, and without
slacking speed perceptibly, grasped it with a downward lunge of
one foot and wheeled back to its perch triumphant. If a piece of
meat about an inch square was accidentally dropped in the tall
herd's grass when flying to the woods, where I, searching keenly,
could not find it, the bird poised in mid-air above the spot would
see it instantly, alight and eat it. They did this on several
occasions. I believe this well illustrates the power of the
eyesight when a foraging Marsh Hawk sails over a meadow searching
for field mice. Small chance a moving body has of escaping the
keen eye!
Voice.--The several notes of the
marsh hawk have been variously interpreted by different writers.
Mr. Forbush (1927) has made a choice collection of these, which I
quote with authorities:
Alarm call of male, "a shrill screaming
'cha-cha-cha-cha-cha-cha' " (Florence M. Bailey); female,
"a prolonged shriek---'kee, kee, kee, kee, kee, kee, kee, kee'
"; or " 'check-eck, check-eck, check-eck, check-eck,
check-eck, check-eck' " (Bailey); "a series of syllables
like 'kuh! kuh! kuh!' repeated very fast and quite a number of
times without pause (H. O. Green); female when disturbed at nest,
a flicker-like call sounding like 'pe'-ter pe'-ter pe'ter';
another call 'stee-whit-a-whit-a-whit,' also 'pee pee pee'
repeated fifteen to twenty times and 'swit, wat, wat,' the notes
sometimes run together like a whinny (C.W. Townsend); rather weak
nasal whistle, also a sort of chuckle; at nest with eggs
'quip-quip-quip-quip-quip'; male at times has a complaining ,
scolding note like 'chu-chu-chu' or 'choo-choo-choo,' quite unlike
the usual short, weak but sharp whistle of the bird--this when
nesting area is invaded. The male's voice is deeper, fuller, and
heavier than the female's higher-keyed note (J. A. Farley).
Field marks.--The adult male is
the whitest of any of our common hawks, with black wing tips. In
all plumages, the white rump is conspicuous. The everglade kite,
Harris's hawk, and the rough-legged hawk all have similar white
patches; the first two have comparatively restricted habitats in
the South and have other field marks; the rough-legged hawk is a
more heavily built bird and has the white mainly on the tail
instead of on the rump (upper tail coverts). At any reasonable
distance the marsh hawk can be recognized by its slender form, its
long slim tail, and its long wings, held at an upward angle except
when soaring. Its manner of flight described above, is
distinctive.
Fall.--Late in August or early in
September the fall migration begins in New England. Mr. Forbush
(1927) says: "The principal migration here seems to move
along the coastal plain. Many marsh hawks coming south through the
region below Boston follow down the west side of Buzzards Bay and
then turn westward across Narrangansett Bay and along the coasts
of Rhode Island and Connecticut."
By the middle of November most of these hawks have left the
northern parts of their range, though they linger on the way as
long as they can find enough mice and small birds to hunt. Audubon
(1840) writes: "I have observed it in our western prairies in
autumn moving in flocks of twenty, thirty, or even as many as
forty individuals, and appearing to be migrating, as they passed
along at a height of fifty or sixty yards, without paying any
attention to the objects below; but on all these occasions I could
never find that they were bent on any general course more than
another; as some days a flock would be proceeding southward, on
the next to the northward or eastward."
Maurice Broun's (1935) records for 1934 at Kittatinny Ridge in
Pennsylvania "extend from September 24 to November 24. The
majority of the 105 individuals recorded passed through between
October 10 and November 10. The greatest number seen on one day
was 11 on October 18, and 11 on November 3. The females precede
the males, apparently, as most of the 51 birds that occurred up to
October 19 were of the former sex. Of 38 Marsh Hawks observed from
November 1 to 12, 28 were males."
Winter.--A few individuals remain,
during mild winters, on the coastal mashes of southern New
England, or in other suitable localities throughout the Northern
States; but the great majority follow the migrations of the small
birds southward, and spend the winter in the Southern States, the
land of plenty.
Northern Harrier*
Circus cyaneus
[Marsh Hawk]
*Original Source: Bent,
Arthur Cleveland. 1937. Smithsonian Institution United
States National Museum Bulletin 167 (Part 1): 78-95. United States
Government Printing Office
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