Fauna Series No. 3

Fauna of the National Parks — No. 3 Birds and Mammals of Mount McKinley National Park

Birds

DESCRIPTIONS OF BIRD SPECIES

EASTERN GOSHAWK
Astur atricapillus atricapillus [WILSON]

GENERAL APPEARANCE.—The largest of the short-winged hawks with a long narrow banded tail and short rounded wings. It is smaller than the red-tailed hawk. Length, 22 inches.

IDENTIFICATION.—The adults are almost all over light gray, finely vermiculated with darker gray below. The juvenile birds are striped brown and white below. The long tail, and the short rounded wings that beat rapidly when the bird is in hurried flight are good distinguishing characters for this species.

DISTRIBUTION.—It breeds in the northern wooded sections across the continent. It is rare in McKinley Park and is confined to the lower timbered sections along the rivers.

HABITS.—On June 12, 1926, a bird of this species circled near us while we were examining a sheep lick on Ewe Creek, near the northern boundary of the park.

In 1932 an old nest of this hawk was found near McKinley Park Station. In this same locality a hawk of the species had been secured early in February 1932. This bird was saved as a specimen.

It is a rather rare resident in the lower aspen forested sections of the area (fig. 10).

SHARP-SHINNED HAWK
Accipiter velox velox [WILSON]

GENERAL APPEARANCE.—A small grayish short-winged hawk with a long, barred, square tail, and short rounded wings. Length, 11.2 inches.

IDENTIFICATION.—The round wings and the blue back of the adult "sharp shin" are readily distinguished from the slender, pointed wings, and reddish back of the sparrow hawk.

DISTRIBUTION.—It nests in the coniferous forests of Alaska and Canada. It was observed in the McKinley region only as a migrant.

HABITS.—On August 17, 1932, near Wonder Lake, I shot and wounded a large female hawk of this species. However, the bird was only slightly hurt and after allowing me to approach within 6 feet of her, she suddenly regained enough strength to fly away as though uninjured. It is believed that this individual was a rare fall migrant from farther north since no hawks of this species had been seen in the Wonder Lake area in midsummer.

HARLAN'S HAWK
Buteo borealis harlani [AUDUBON]

GENERAL APPEARANCE.—A large dark-colored hawk of the red-tailed type with broad, long, rounded wings, and a short chunky body. The four outer wing feathers are notched.

It is a noisy hawk that sits on exposed perches or soars in wide circles out in the open. When the bird is in flight, the tail is usually carried spread out in a fan shape. And in soaring birds, the length—the distance from the tip of the bill to the end of the tail—is less than half the spread of the outstretched wings. Length, 22 inches.

IDENTIFICATION.—The dark-colored tail, not white at the base, and heavy unfeathered tarsus (legs) distinguish Harlan's hawk from the American rough-legged hawk. Swainson's hawk is the only other large soaring hawk in the McKinley region and it has a decidedly smaller bill and more slender form than harlani.

DISTRIBUTION.—This species breeds in northwestern British Columbia, southwestern Yukon Territory, and in the adjoining parts of Alaska, at least as far west as Mount McKinley.

HABITS.—The Harlan's hawk is found in the McKinley region along the larger streams where trees of black cottonwood and spruce are found. Hawks of the species were first seen by us on May 24, 1926, in spruce timber near Savage River (fig. 6). On June 3, 1926, a pair of Harlan's hawks was found near this same place. They were perched in the very tops of large spruce trees and uttered the typical red-tailed hawk scream.

On July 19, 1926, a breeding pair of these birds was located at the south end of Wonder Lake. They were perched in a tall spruce beside their large bulky nest built of sticks. On July 27, George Wright collected an immature female Harlan's hawk, not long out of the nest, at Fish Creek on the lower Savage River. In 1932, a mated pair of Harlan's hawks was noted on June 4, 8, and 11, near the Igloo Creek cabin. Harlani is a regular breeding species in the Mount McKinley National Park.

All of the 15 hawks of the red-tailed type seen in the park both in 1926 and 1932 were of the dark harlani type; not a single light-colored bird was seen.

SWAINSON'S HAWK
Buteo swainsoni [BONAPARTE]

GENERAL APPEARANCE.—A soaring hawk with broad, rather pointed wings. It is slightly smaller than the red-tailed hawk with slenderer, bare legs but never with a red tail. In the Swainson's hawk only the three outer wing feathers are notched. There is great color variation in this species, ranging from a very light color on the under parts to almost black. Length, 20 inches.

IDENTIFICATION.—This species may be distinguished in the field from the rough-legged hawk by its lower legs which are bare, not feathered. The slender, lighter build and wing tips which are more pointed with only three notched primaries, instead of four, will distinguish it from the Harlan's hawk.

DISTRIBUTION.—It breeds from the Mount McKinley region, Fort Yukon, and Great Slave Lake south through British Columbia and Manitoba to northern Mexico. In the McKinley region we only encountered it at Wonder Lake.

HABITS.—The only record that we have of this species for the region is of an adult, dark-colored female collected August 8, 1932, at Wonder Lake, where it sometimes breeds.

AMERICAN ROUGH-LEGGED HAWK
Buteo lagopus s. johannis [GMELIN]

GENERAL APPEARANCE.—A large hawk about the size of the Harlan's hawk. Both light and dark phases occur in this species. The lower legs of the rough-legged hawk are feathered clear down to the base of the toes. When seen circling overhead, conspicuous white areas often show at the base of the tail and near the tip of each wing. Length, 22 inches.

IDENTIFICATION.—The white area at the base of the tail and on each wing, together with the fully feathered legs, distinguish it at once from all other large hawks of the region.

DISTRIBUTION.—It breeds from the Aleutian Islands along the Arctic coast of Alaska, to Victoria Island, Baffin Island, and Newfoundland. It was observed by us at the head of Savage River and at Copper Mountain.

HABITS.—We encountered this species first on June 18, 1926, near the head of Savage River. On that day, an American rough-legged hawk circled about a high cliff, returning several times. The white area at the base of the tail, with the terminal dark band, and the two other light areas, one near the tip of each wing, made identification easy.

On July 1, 1926, at Jenny Creek, five northern phalaropes were feeding busily in a small pond. They flew in precise military order upon our approach. Seeing the flying birds, a rough-legged hawk made a dart at one of the phalaropes but missed it and resumed his course low over the tundra. Only 10, 1926, another hawk of the species was observed hunting for mice along a grassy slope.

This hawk, like several other species, was not found in this same area in 1932. We therefore consider it an occasional rather than a regular summer visitor to the McKinley Region.

GOLDEN EAGLE
Aquila chrysaetos canadensis [LINNAEUS]

GENERAL APPEARANCE.—The two largest hawklike birds found in the McKinley region are the golden and northern bald eagles. In this area, any bird of prey 30 inches or more in length and having a spread of more than 6 feet from tip to tip of the wings may safely be called an eagle. Length, 30 inches.

IDENTIFICATION.—The large size and general dark brown coloration, together with the long narrow wings; the massive bill, which is nearly as long as the head, and the legs, which are feathered to the toes, are all good field characters of the golden eagle. Some of the birds of this species have golden or even cream-colored heads and a similar light-colored area at the base of the tail, but the entire head and tail is never pure uniform white as in the adult bald eagle.

DISTRIBUTION.—The golden eagle inhabits the northern part of the northern hemisphere. In North America it is rare east of the Mississippi River, but in the mountains of the west, from the Mexican boundary to northern Alaska, it is still found well represented in suitable localities. This is the common breeding species of eagle in the McKinley region where it is widely distributed and relatively abundant.

HABITS.—The huge eagle nests composed of large and small interlaced sticks are interesting and characteristic features of the park. These nests are usually placed on the cliffs in selected niches that have a warm, southern exposure. Each pair of eagles has a well defined territory, or hunting ground, which in the McKinley region was found to cover an average area of about 10 square miles.

Sheldon noted golden eagles which were active about their nests, in the spring, as early as April 8. At Toklat, he found eggs in an eagle's nest on April 29; when he visited the nest a month later, the eggs had hatched.

On June 12, 1932, at Double Mountain, I found an eagle's nest that contained two downy eaglets about 1 week old. On July 15, I visited the nest again and found that it was occupied by a single eaglet. In 40 years of experience in studying the nesting of golden eagles I have found that although two eaglets are usually hatched, in many instances only one grows up. From experience which I have had with captive downy eaglets, I am inclined to believe that in the lively battles over food one of the eaglets may be driven to the rim of the nest and may even fall entirely out of it. In most instances it has been the larger, older eaglet that disappears from the nest about the time that the flight feathers begin to make their appearance. Close observation at the eagle's nest in July showed that at this stage of development the eaglets spend considerable time standing at the edge of the nest flapping and exercising their growing wings which often became unmanageable in sudden gusts of wind. Twice I saw one eaglet nearly blown out of the nest by an unexpected wind flurry. In each instance the bird saved itself by desperately clutching its talons into some solid stick that was tightly built into the nest. However, not all of the sticks forming the rim of a nest are solidly anchored and the finding of a dead eaglet and loose sticks at the base of the cliff below an eagle's nest leads us to believe that some of the more venturesome young fall from, or are blown out of, their nests by these sudden gusts of wind.

On July 17, 1926, we found that a pair of golden eaglets had just left their nest on a large cliff near the north end of Wonder Lake. This nest had been used regularly by a pair of eagles for several years.

At Stony Creek on July 11, we found an eagle's nest containing young. They could he heard calling a mile distant. The call of the golden eagle is not a scream, it is low pitched and resonant and carries a long way.

In the McKinley region the golden eagles depend primarily upon ground squirrels and hoary marmots for food. An incident observed on July 8, 1932, near the East Fork of the Toklat, suggests the possibility of foxes falling prey, at times, to the eagles. While we were returning from Stony Creek a very tattered adult red fox was observed crouching in the open beside the road; it was within a few feet of a galvanized iron culvert and was very loathe to run even when closely approached. At first we could not understand its tameness, but we were soon enlightened, for a golden eagle swooped down at the fox. A large male cross fox was found hiding nearby in the culvert. When we drove him out of it, he started off full speed down the open road, but he had gone less than a hundred yards when there was a sudden "hiss of wings" and the eagle shot down like a rocket and attempted to clasp the fox in its talons. The animal evaded the blow by jumping to one side just as the eagle struck. The moment the eagle attacked the second time, the fox fluffed out his tail and stuck it straight up over his back. It served as a protecting foil, attracting the eagle's blow so that the fox again escaped. The third attack of the eagle was frustrated by the fox diving into a narrow crack in the solid rock, under a large boulder, where we found him with just his nose sticking out. This fox was so fearful of the eagle that he allowed us to approach within 3 feet and even then we could not get him to risk the open again. Instead, he merely withdrew as far back as possible into the shallow, narrow crevice where we left him trembling, his eyes glowing like twin coals of fire.

Marmots are a favorite food of eagles. They proved to be the mammal most frequently brought to the young eagles in the nest that I watched at Double Mountain. On June 3, 1926, at Savage River, we watched a golden eagle circling high over a fat old marmot that was cautiously sneaking back to its den by a series of alternating short rapid runs and hidings in thick vegetation. The mere appearance of a golden eagle about a marmot den brings forth a series of sharp explosive whistles which warn every mammal within hearing distance that danger is near.

On the afternoon of August 26, 1932, while stalking mountain sheep with the camera, I climbed up a jagged crest and surprised a golden eagle that was perched on a rocky summit eating a male Alaska ptarmigan which it had just captured. The eagle had carefully plucked the feathers off the ptarmigan before eating the bird. Another eagle was seen in hot pursuit of a ptarmigan. The ptarmigan's wings were going like an electric fan, while the eagle's wings flapped only at a moderate speed. The ptarmigan soon became exhausted and was forced to drop for safety into a willow thicket. Had the willows been absent at the critical moment, the eagle would have secured a toothsome meal.

We have been unable to obtain any authenticated instance of eagles killing young caribou, I have no direct evidence that eagles capture young mountain sheep but certain observations indicate that eagles might, at times, pick up a few unguarded lambs. On May 25, 1908, near Toklat, Charles Sheldon witnessed an attack which he describes (1930, p. 366-7) as follows: "While watching through my field glasses, a golden eagle suddenly came over the crest and with wings extended, made a swoop at the ewes, coming within 3 feet of them. They jerked up their heads, trying to strike the eagle with their horns. . . . After this attack the ewes, keeping the lambs directly under them, watched alertly for 5 minutes for the reappearance of the eagle. . . . After another 5 minutes the eagle came soaring from behind them. But they quickly saw it and stood over their lambs. The heads of the ewes were held stiffly up, tipped a little to one side, ready to hook at the eagle, should it come too close. As it passed 15 feet above them it swooped somewhat indifferently, and quickly rose. . . . On June 7, 1908, Sheldon visited the eagle's nest at the forks of the Toklat and found "strips of skin and other remains of lambs" on the nearby rocks, showing that the eagle had been successful in his attack on sheep or had picked up carrion.

A careful study of four eagle nests all containing young was made in 1932, but I was never able to find any fresh remains of lambs in or below any of them. However, it should be stated that the lamb crop of 1932 was unusually poor. Sheldon states (1930, p. 383) that "after the lambs are over a month old they are seldom molested." Our experience in the region both in 1926 and in 1932 indicated that during these two seasons lambs were rarely taken by eagles, which were found to live chiefly upon ground squirrels and marmots.

It should not be assumed that the eagle is always king of the air. On July 21, 1926, near the East Fork of the Toklat, I watched a gyrfalcon actually drive an eagle away from a cliff where both the eagle and the falcon nested. On July 13, 1926, at Copper Mountain, an adult short-billed gull was observed to drive an eagle away from a pond in which a downy young gull was paddling.

On August 23, 1932, at Igloo Creek, I watched three magpies take a ground squirrel away from a golden eagle. When first seen the eagle was standing on the ground eating the squirrel which it had just captured; as the three magpies flew by, they spied him. Two of the magpies then took turns swooping down at the eagle's head. The moment the eagle was forced to relinquish his hold on the squirrel in order to combat the attack of these two magpies, the third magpie slipped in and grabbed the squirrel, carrying it off while the eagle's attention was distracted. Later all three magpies feasted peacefully on the squirrel which they had stolen from the eagle.

One of the outstanding avian citizens of Mount McKinley National Park, the golden eagle should be preserved as an integral part of the native fauna.

NORTHERN BALD EAGLE
Haliaeetus leucocephalus alascanus [TOWNSEND]

GENERAL APPEARANCE.—A very large dark brown, hawklike bird. The adult has a conspicuous white head, neck, and tail. This conspicuous white is lacking in the immature bird which is entirely dark colored, save for various lighter mottlings. Length, 33 inches.

DISTRIBUTION.—They are found chiefly along the seacoast, or more rarely near large lakes, in the northern half of North America.

IDENTIFICATION.—Because of its large size and its white head, neck, and tail, the adult bird is unmistakable. Both adult and young birds have yellow feet and the tarsus, or lower leg, is bare—not feathered to the toes as is the tarsus of the golden eagle. Immature bald eagles lack the light spot near the under tip of the wing and the light band near the tip of the tail, both of which characters are often present in immature golden eagles.

HABITS.—The northern bald eagle is a rare straggler in the park. On May 15, 1932, near Windy, I saw an adult white-headed eagle flying up the Nenana River in the direction of Broad Pass and the south side of the Alaska Range.

MARSH HAWK
Circus hudsonius [LINNAEUS]

GENERAL APPEARANCE.—A meadow-haunting hawk of medium size with long wings, long tail, and partly feathered eye ring—suggestive of an owl. Length, 19 inches.

IDENTIFICATION.—The adult male is light gray above and white below with black wing tips. The female is like the young birds except that it is paler with less red. The juvenile is reddish brown striped with lighter brown below. Both sexes in all plumages may be readily recognized by a broad white band at the base of the tail.

DISTRIBUTION.—It is distributed throughout Canada and the United States.

HABITS.—On June 1, 1926, a hawk of this species was seen flying along Savage River well within the boundaries of the park. It is a rare breeder in the area—this was the only one seen during the entire summer. Sheldon reports that marsh hawks were common on the Toklat, on August 20-21, 1907, where they had been attracted by the abundance of mice.

BLACK GYRFALCON
Falco rusticolus obsoletus [GMELIN]

GENERAL APPEARANCE.—Largest of the true falcons, or "noble" hawks. In flight, falcons may be readily recognized by their long pointed wings and their direct bulletlike flight which is accomplished by quick strokes of the wings with relatively little sailing.

Another diagnostic feature of the falcons is the toothlike projection near the middle of each cutting edge of the upper half of the bill, which in all other hawks is sharp but even, not toothed. Gyrfalcons vary greatly in color, some being almost pure white, others nearly black. All of the gyrfalcons that we observed in the McKinley region ranged from gray to very dark gray. Length, 22 inches.

IDENTIFICATION.—The long pointed wings, rapid wing beats, and large size are all good field characters for gyrfalcons in flight. As, in our experience, the birds were nearly always in flight when observed, these characters proved most useful.

DISTRIBUTION.—Gyrfalcons inhabit the Arctic regions of both hemispheres. In North America they are found from the Alaska peninsula north to Point Barrow and east to Labrador. In the McKinley region in 1926, breeding pairs were found in Savage River Canyon and at Wonder Lake and Copper Mountain. In 1932, these same nesting sites were again visited and not a single gyrfalcon was present.

HABITS.—As previously indicated, gyrfalcons were nesting rather commonly in the McKinley region in 1926, when rabbits and ptarmigan were abundant. However, in 1932, when varying hares were at their periodic minimum and ptarmigan were just beginning to regain their former numbers, these large falcons were absent from their former nesting sites and not one bird of the species was seen during the entire summer. The pot holes in the cliffs, which had been used as nest sites, also showed that they had not nested there in 1931.

At Copper Mountain on July 20, 1926, we watched a family of four young gyrfalcons just out of the nest. They were flying about after their parents begging and calling loudly for food.

Another record of the presence of a pair of gyrfalcons in 1926 and their subsequent absence in 1932 was obtained from observations made in the Savage River Canyon. In 1926, a pair of gyrfalcons bred in this canyon and we watched them carrying ground squirrels and ptarmigan to their eyrie. During the summer of 1932, we visited the nest several times but the birds were absent.

It seems probable that the gyrfalcons have cycles of abundance, and the breeding birds move about over wide areas following closely upon the movements of rabbits, ptarmigan, and other small game upon which they subsist. In the future it will be interesting to check the years of abundance of rabbits and ptarmigans in the McKinley region and compare this abundance with the number of breeding pairs of gyrfalcons during the same period. It seems likely that the gyrfalcons will continue to be rare or wanting, in the McKinley area until such time as the rabbits and ptarmigan again become plentiful.

WESTERN PIGEON HAWK
Falco columbarius bendirei [SWANN]

GENERAL APPEARANCE.—A small falcon, similar in size and coloration to the sharp-shinned hawk but with more pointed wings and shorter tail. The general appearance is that of a diminutive duck hawk. The back of the adult male is slate-blue and the tail is barred with the same color. The under parts are white or cream and more or less heavily streaked with ochre or brown. Both the back and the tail of the female and juvenile are brown and the under parts are cream, or deep buff, heavily streaked with dark brown. Length, 10 inches.

IDENTIFICATION.—The pigeon hawk is a true falcon, shown by the "toothed" bill and pointed wings. It lacks the red on the wings and tail of the sparrow hawk which is the only other small falcon in the McKinley region.

DISTRIBUTION.—According to the fourth edition of the American Ornithologists' Union "Check List of North American Birds", the Western pigeon hawk is the form breeding in northwestern Alaska, Yukon, and northwestern Mackenzie.

A specimen of a male just acquiring the blue feathers of the adult bird was collected by George M. Wright on May 25, 1926, at Savage River. This is now specimen no. 49705 M. V. Z. in the bird collection of the Museum of Vertebrate Zoology and Dr. Joseph Grinnell pronounced it as belonging clearly to the western form, namely, Falco columbarius bendirei.

HABITS.—Sheldon (1930, p. 401) states that he found the pigeon hawk a common summer resident and that it bred on the Toklat, and was first noted in the spring on May 27. On May 26, 1926, a family of three young Alaska jays were noted perched in the top of a dead spruce where they remained motionless and refused to fly as long as a pigeon hawk was present in that vicinity. Robins and other birds in the neighborhood uttered alarm and distress notes whenever the pigeon hawk appeared.

Figure 20.—Young pigeon hawk in white natal down, with flight feathers developing on wings and tail. Photograph taken July 9, 1932 Igloo Creek. W. L. D. No. 2616.

The crop contents of a family of young pigeon hawks, which were found and studied at Igloo Creek, consisted chiefly of Gambel's and tree sparrows and other passerine birds.

On the morning of July 7, 1932, a pigeon hawk was heard calling repeatedly in a grove of spruce trees near an old igloo. There were no dead trees with suitable cavities for a falcon nest site in this grove, but I felt certain from the solicitude of the adult female bird that she had a nest there, and after much searching, five downy pigeon hawks were located in a magpie nest in the thickly foliaged top of a spruce tree. These young falcons (fig. 20) were about half grown, with flight feathers emerging all along their wings and tails. The eyes of the young were bluish-black; the cere was greenish-yellow; and the feet were light yellow. These young falcons left the nest on July 11, as soon as they were able to climb about from branch to branch, but they remained in the top of the nest tree, or in other trees nearby, until July 23, at which time their flight feathers and wings were well enough developed so that they were able to fly about. They were never seen near the nest again.

The pigeon hawk nests regularly in the lower timbered areas in Mount McKinley National Park.

EASTERN SPARROW HAWK
Falco sparverius sparverius [LINNAEUS]

GENERAL APPEARANCE.—Smallest representative of the falcon family. It is the only small hawk in the McKinley region that shows bold black and white facial markings in both sexes. Other distinctive markings of this species are the red back and tail of the male and the general rusty color of the female. Length, 10 inches.

IDENTIFICATION.—The red back, bold black and white facial markings, small size, long pointed wings, and the habit of hovering stationary on rapidly beating wings are all good field characters.

DISTRIBUTION.—It ranges across North America north to the limit of the trees, and is found breeding sparingly in the McKinley region at a low elevation along the larger streams.

HABITS.—Our first acquaintance with this species in the McKinley region was on May 19, 1926, when Wright saw a brightly colored male at Savage River. In 1932, I saw the species twice: on August 1, when a male bird of the year was collected at McKinley Park Station, and on August 14, at Moose Creek, when another male was observed perched in a dead cottonwood. It is a rare but regular breeder in this region.

NEXT >>>

Last Modified: Thurs, Oct 4 2001 10:00:00 pm PDT
http://www.cr.nps.gov/history/online_books/fauna3/fauna9d.htm