Red-throated Loon

BREEDING MALE

The Red-throated Loon is a small loon with a thin bill that is often held up at a slight angle.

Male/breeding plumage:
– Reddish throat.
– Gray head.
– Brownish upperparts.

Photograph © Glenn Bartley

Female

Seasonal change in appearance

Juvenile

Habitat

Diet

Behavior

Range

Fun Facts

Vocalizations

The nest is a pile of vegetation.

Number: 2.
Color: Olive with darker markings.

Incubation and fledging:
– Young hatch at 24-29 days.
– Young fledge (leave the nest) in a day after hatching but remain with the adults for some time.

Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.

Bent Life History for the Red-throated Loon – the common name and sub-species reflect the nomenclature in use at the time the description was written.

The rugged coast of Labrador, with its chain of rocky islands, icebound for nine months of the year and enveloped in fog or swept with chilling blasts from drifting icebergs during most of the other three, seems bleak and forbidding enough as we pick our way through the narrow channels back of the outer islands. But in the interior it is different. Though the summer is short, the sun is high in the heavens and the days are long; the abundant moisture in the air stimulates the growth of vegetation; the snow disappears rapidly and the verdure of spring follows quickly in the wake of retreating winter. Within a few feet of a vanishing snow bank I have seen the dwarfed willows, recently uncovered, already budded and bursting into leaf and a few yards farther away fully leaved out or even blossoming. Back from the rocky coast only a short distance the rolling hills are softly carpeted with deep mosses, covered with fresh verdure and dotted with blooming wild flowers in great variety and profusion. Here among the thousands of small lakes and ponds in the sheltered hollows, fed with the water from melting snow and studded with little islands, the red-throated loons find a congenial summer home and hither they come as soon as the fetters of winter are unlocked. We saw them everywhere along both the south and north coasts almost daily, flying inland to the lakes or even about the little ponds on the islands.

Courtship: Audubon’s (1840) graphic pen thus describes their courtship:

High over these waters, the produce of the melted snows, the red-throated diver is seen gamboling by the side of his mate. The males emit their love notes, and, with necks gracefully curved downward, speed by the females, saluting them with mellow tones as they pass. In broad circles they wheel their giddy flight, and now, with fantastic glidings and curves, they dive toward the spot of their choice. Alighted on the water, how gracefully they swim, how sportively they beat it with their strong pinions, how quickly they plunge and rise again, and how joyously do they manifest to each other the depth and intensity of their affection. Now with erected neck and body deeply Immersed they swim side by side. Reynard they perceive cunningly advancing at a distance; but they are too vigilant for him, and down like a flash they go, nor rise again until far beyond his reach. Methinks I see them curiously concealed among the rank weeds under the bank of their own islet, their bills alone raised above the water, and there will they remain for an hour, rather than show themselves to their insidious enemy, who, disappointed, leaves them to pursue their avocations.

Many of the birds are paired before they start on their northward migration, as they are often seen migrating in pairs, traveling high in the air, their long necks pointing northward and their white breasts glistening in the sunlight. Perhaps they are mated for life, as the common loon is supposed to be. They often arrive on their breeding grounds while the lakes are still frozen, when they frequent the mouths of rivers or the open sea until the melting snows produce the first pools of water in the interior and their summer homes become habitable. After that they return to the sea only to feed.

Throughout northern Alaska the red-throated loon is the most abundant and most widely distributed species, a characteristic feature of the Arctic tundra, where it can be seen at any time flying up or down the rivers or to and from the tundra pools. The harsh. goose-like, honking calls or the weird, shrill cries of this species may be heard at all hours of the day, or even during the short Arctic night, the most characteristic sounds of these northern solitude’s.

Nelson (1887) says:

At St. Michaels and the Yukon they arrive with the first open water from May 12 to 20, and by the end of this month are present in large numbers. Their arrival is at once announced by the hoarse, grating cries, which the birds utter as they fly from place to place or float upon the water. When the ponds are open on the marshes the red-throated loons take possession, and are extremely noisy all through the first part of summer.

Nesting: The nesting habits of this species are in no wise different from those of the other loons. Mr. Lucien M. Turner, in his unpublished notes, gives the following good description of a typical nest:

A nest of dry grass stalks and blades, together with weeds and sticks, was found on one of the small islets off the mouth of Whale River, Ungava, July 1, 1884. The interior of the nest was of fine grass and few feathers which from the dampness of the situation or material used in construction of the nest had become discolored beyond recognition. Three eggs, of the dark pattern of coloration, were in this nest. They were quite fresh, the last egg had probably been just deposited. The bird fluttered Into the pool, on the margin of which the nest was placed, and then floundered through the weeds and grass beyond from which she took to rapid flight and either she or her mate returned after awhile and hovered around in circles uttering an occasional ka: ka: ka; and, at times only a growling, single syllable of the note.

Mr. M. Abbott Frazar (1887) took seven sets of eggs of this species in southern Labrador and says that it breeds on the edges of the smaller ponds (often mere pools of surface water only a few rods square), on the larger islands they make no nest, but simply lay their eggs in a slight hollow on the bare ground, usually on a slight rise not over 1 foot from the water’s edge. The space about the egg is perfectly bare, the grass or other vegetation being trampled flat. Hence the spot is easily discovered, and the bird if sitting can be seen for a considerable distance.

Audubon (1840) says:

The nest was placed within a few feet of the water, and xvell-beaten tracks, such as are made by otters, led to it. Whenever the birds went to this spot they walked nearly erect In an awkward manner, but when they sat in their nest they laid themselves flat on the eggs, in the manner of a goose or duck. In no instance did they alight on the islands, but always on the water, at some distance, when, after examining all around them for awhile, they crawled silently out, and moved to the spot which contained their treasure.

In northern Alaska, Nelson (1887) noted that the eggs “are laid directly upon the ground, and the spot chosen is frequently wet and muddy. One nest was found on frozen ground, and ice was floating in the pond.”

Dr. Joseph Grinnell (1909) describes a nest found at Glacier Bay, Alaska, on July 16, 1907, as follows:

This was in the rank grass at the edge of a pond a few yards back from the shore of one of the small islands on the east side of the bay. The parent was seen to swim away from the nesting place, and by her peculiar actions indicated its proximity. There were two eggs on the point of hatching. Instead of the usual floating structure, the eggs in thIs case rested on the bare, wet mud, 2 feet back from the water’s edge, there being no nesting material whatever.

Eggs: The red-throated loon, like others of this genus, regularly lays two eggs. Most writers agree that this is the invariable number, but Audubon and some others have stated that three eggs are often laid. Sets of three must be exceptional, and occasionally one egg may be all that a nest contains. Frequently only one young bird is hatched, but in such cases the other egg is infertile.

The egg is “elliptical ovate” or “cylindrical ovate” in shape, with occasionally a tendency toward “ovate” or toward “fusiform.” The shell is smooth and somewhat glossy. The ground color is “bister” or “sepia” in the darkest eggs, “auburn,” “Brumels brown,” “brownish olive,” “light brownish olive,” or “Saccardo’s umber” in others, and “Isabella color” or “deep olive buff” in the palest eggs. Some eggs are nearly spotless, but usually they are sparingly and irregularly spotted with small spots or with scattering larger spots, rarely with irregular blotches, of the darkest shades of brown, such as “clove brown” and “blackish brown”; some eggs also have underlying spots of various shades of drab and very rarely these are the only markings. The measurements of 58 eggs, in the United States National Museum, average 72.5 by 45; the eggs showing the four extremes measure 80 by 47, 79.5 by 48, 62.5 by 41.5, and 68 by 40.5 millimeters.

The period of incubation seems to be unknown; it is probably somewhat less than that of the common loon, as it is a smaller species. Both Yarrell (1871) and Macgillivray (1852) state that both sexes assist in the incubation. Certainly the pairs remain together all through the breeding season, to guard the nesting site and to care for the young jointly. Macgillivray (1852) says:

The female continues to sit, crouching over her eggs, until a person comes very near, when she starts forward, plunges into the water, and on emerging usually takes to wing, but sometimes swims about with great anxiety, as does the male, should he happen to be present. On being deprived of their eggs, they may he heard for several evenings lamenting their loss with loud melancholy cries.

Young: Both parents are very solicitous in the care of the young. When danger threatens the old bird sinks her body below the surface, with only the head and neck stretched up above it, the young bird climbs upon her back and she swims away with him to safety.

The young are experts at swimming and diving; they are soon taught to hide among the vegetation while their parents draw attention to themselves by flying excitedly over the pond or swimming in circles a short distance from the shore. Mr. Edward A. Preble (1908) noted that: When the nesting pond was approached, the male Usually flew away, but the female invariably refused to leave her offspring, and if absent soon appeared and alighted beside them, diving, swimming about, and encouraging them in 4:heir efforts to escape, and endeavoring to attract the attention of the intruder to herself. The old birds fished in the lake near by and were often seen carrying small fishes to the young.

Nelson (1887) says:

The young are led to the streams, large lakes, or sea-coast as soon as they are able to follow the parents, and they fall easy victims to the hunter until, with the growth of the quill feathers, they attain some of the wisdom of their parents. The end of August sees all upon the wing, except now and then a late bird, and from September 15 to 30 they gradually become more and more scarce, until only a very few can be found the first of October.

Plumages: The young loon when first hatched is completely covered with short, thick, dark brown down, “seal brown” above, shading gradually to “drab” below. As it increases in size these colors become paler, particularly on the under parts, which fade out to “light drab” or “ecru drab” on the belly and to dark “walnut brown” above. A series of young red-throated loons, collected by Turner in Ungava, shows that their development is very slow. A young bird, collected July 30, was evidently hatched very early, but it is still wholly downy, although nearly half grown, and the wing quills are only just started. Another, collected September 19, is in the juvenal plumage and fully grown, but there is still some down on the flanks and hind neck. Turner states in his notes that this bird “would not have been able to sustain flight for fully another month.” Evidently, as in the ducks, the body plumage is fully acquired and the last of the down has disappeared from the flanks Long before the primaries are grown and the flight stage is reached.

In the juvenal plumage the head and neck are mottled with “n~iouse gray” and dirty white, the gray predominating on the crown and throat; the upper parts are dusky, mottled on the back and wings with “drab-gray” spots or V-shaped markings; these markings are much larger and more decidedly V shaped on the scapulars, becoming smaller and more broken up into rounded spots on the back. This plumage is worn without any very decided change throughout the winter; there is considerable individual variation in the size, shape and arrangement of the markings; but as a rule the gray mottling gradually disappears from the throat and the markings on the upper parts become whiter, smaller and more rounded, as the season advances. The V-shaped markings, however, are characteristic of the first winter plumage and never disappear entirely during the winter; they are never seen in any subsequent winter plumage and may consequently be regarded as sure signs of immaturity.

At the first prenuptial molt, which is only partial, the head and neck acquire a plumage resembling that of the adult, but dull and incomplete; the red throat patch is dull yellowish red and much restricted; the white markings of the back have largely disappeared by wear. At the next complete molt, the first postnuptial, when a little over a year old, the young bird assumes the adult winter plumage. This is similar to the first winter plumage except that the throat is immaculate white, or nearly so, and is sharply separated from the crown which is mottled with dusky gray and white; the back is mottled with round white spots.

The adult has two annual molts; a partial prenuptial molt, involving at least all of the feathers on the forepart of the body, produces the handsome head and neck of the nuptial plumage and quite an extensive growth of dark, new, glossy feathers on the back and scapulars. I have seen the beginning of this molt as early as December 28, but usually it is accomplished during March and April; and a complete postnuptial molt, during the latter part of the summer, produces the adult winter plumage, described above. The adult winter plumage is often not complete until late in the season. I have seen birds in very much worn plumage and only partially molted in December; this plumage is worn for a comparatively short time and the molt into it is often incomplete and sometimes not accomplished at all. I have seen a bird in full spring plumage in October and another, in the same month, in regular winter plumage with the full, rich, red throat of the nuptial plumage. Fall adults are scarce in collections and, if we had them in large series, we might be surprised to know to what extent old birds retain part or all of their spring plumage during the fall.

Food: The food of the red-throated loon consists principally of small fishes which it obtains by diving and chasing them under water. On the coast of Labrador the little capelin is its principal prey, which it flies to salt water to seek. Mr. W. L. Dawson writes to me that: It was a pretty sight to see a straightaway race between this bird and a herring. The fish rose to the surface with tbe bird in hot pursuit, and it took 20 feet, after the bird came near enough to the surface to he seen, to catch the sprat. Once at the surface and overtaken, the fish tried twisting and turning, but the bird was better at it and soon had the fish down. I took pains to notice that the diver did not spear, but seized the fish.

In addition to fish it eats a variety of animal food, when available; frogs, fish spawn, crustaceans, mollusks, shrimps, leeches, and aquatic insects have been reported by various writers; it has even been suggested that it occasionally eats portions of aquatic plants.

Behavior: The flight of this loon is swift, strong and exceedingly direct; it is capable of long sustained flight and it generally flies in a straight line at a great height. The neck is outstretched to its fullest extent, the bill points straight forward and the large feet are exten(led backward, held close together, to serve as a rudder in place of its useless little tail. A long, slender figure, pointed at both ends, with small wings vibrating rapidly, can generally be recognized as a loon at even a long distance, but the various species can not be distinguished with certainty even at a short range except in full nuptial plumage; I know of no field mark by which the young birds may be recognized. The red-throated loon rises more easily from the water than the other species and gets under way more quickly; when alighting on the water it drops in heavily, striking at an angle, making a great splash and plowing up a furrow as it slides along the surface. It swims rapidly on the surface or with its body submerged. In diving it can sink quietly out of sight or dive like a flash, causing scarcely a ripple; but when not hurried or when intending to make a deep dive the neck is arched and the body thrown forward in a downward plunge with the wings closely pressed to the sides. Under water it makes astonishing speed, faster than a man can run along the shore, and it is useless to pursue one in a boat or a canoe; it can even outdistance an ordinary power boat. I believe that it ordinarily swims under water by using its feet alone, working them alternately; but when an extra burst of speed is desired the wings are also brought into play and the result is marvelous. Dr. George Suckley (1880) noted this habit, as follows:

Another individual which I obtained at New Dungeness, Straits of Fuca, I had an excellent opportunity of examining at a time it was attempting to escape from a shallow lagoon to the open water of the straits by swimming through the narrow outlet. Although slightly wounded, it moved so rapidly that I was obliged to run as fast as I could to keep up with it. At the same time, as the water was clear and shallow, I was able to watch its motions distinctly. It had the head and neck extended nearly perfectly straight, the bill acting as a “cut water,” and, in addition to the ordinary propulsion by the feet, used the ~~’ings exactly as if flying. Indeed, the bird was flying through water instead of air.

The ordinary call note of the red-throated loon, which is a very noisy bird on its breeding grounds, is a goose-like, honking cry, which Nelson (1887) has described very well as follows:

The harsh gr-r-f,,a gr-r, gr-r-ga, ga, gr-r, rising everywhere from the marshes during the entire 24 hours, renders this note one of the most characteristic that greets the ear in spring in these northern wilds. The red-throated loon Is one of the very few birds which raised its voice in the quiet of the short Arctic night. In spring, ~vlth cranes, they foretell an approaching storm by th~ in. creased repetition and vehemence of their cries.

Turner writes in his notes:

The Indian name, at Fort Chimo, for this species is Kashagat, derived from its note. This name is derived from the prolonged cry of the bird, which is the syllable ka repeated many times, slowly at first and finally blended, as it flies to or from a feeding place high in the air to command observation, and with accelerated flight to whirl and slowly descend with motionless pinlons to the water, where a splash from the momentum of the bird conceals it as It sinks to slowly rise to reconnoiter the surroundings for danger.

It indulges also in a variety of weird, loud cries, similar to those of the common loon, which are the notes most frequently heard on migrations, especially when calling to each other at long distances on the water or when separated in a fog. Mr. William Brewster (1883) has described these notes very well as follows:

On calm mornings the male sometimes indulges in a prolonged outburst of harsh, discordant cries, which are uttered with such volubility and variety of intonation that one might Imagine a dozen birds to be engaged. This performance reminded me of the clamor of a flock of geese. It was evidently the loon’s masterpiece, for during its production he would sail proudly about on the water with erect head and swelling plumage. It was so loud that it could be heard at a distance of a mile or more.

Fall: As soon as the young birds are able to fly and the molting season of the adults is practically over, sometime in September, they begin to leave their breeding grounds and by the first. of October are all on the way south. The migration along the New England coast is mainly in October accompanying the main flight of the scoters. After leaving the fresh-water lakes of their summer homes they resort to the seacoast for migration and seem to prefer to spend the fall and winter on salt water. When traveling they fly at a great height and in a direct course along the shore, a mile or two out from the land; they usually fly singly, although often several are in sight at one time, widely scattered. There is, however, some feeling of sociability among them, most noticeable on foggy days, when they manage to keep in touch with each other by frequent interchange of call notes, as if helping each other to maintain the same general line of flight. They are even somewhat gregarious at times, gathering in small parties on the water to rest and calling to their passing companions; these gatherings are sometimes quite noisy and are well known to gunners as “loon caucuses.” They are shy and difficult to approach on the water at such times, but when migrating they pay but little attention to the gunner’s boat, swiftly passing over it in a direct course; they are often shot at, but seldom killed, for their densely feathered breasts are almost impervious to shot and they are very tenacious of life; if wounded, it is useless to pursue one, for it is more than a match Thr its enemies when in the water.

Mr. W. L. Dawson tells me the following interesting story of how one of these loons helped another out of a difficulty. He came upon a red-throated loon wrestling with some crude oil under its wing, within a few feet of the water on a California beach. He writes:

The bird awaited my approach warily, as If realizing the disadvantage of his position, but as I pressed too close with focussed camera, he sprang to wing, provoking me to a futile snap, plumped into the water almost immediately and struck out for deeper water. A mate, I will not say the mate for there were two red-throated loons in sight, saw his comrade’s plight and hurried forward so eagerly that he took wing in his anxiety to succor, and did the “shoot-the-chutes” act with a fine display of wing and splash of water. Alter this the newcomer pressed forward toward me, as though to cover his comrade’s retreat and paraded up and down at close quarters while the other bird was pulling away. It was difficult to believe that either parental Instinct or sex gallantry took a part here. It was more likely a bit of fraternal altruism.

The inland migration route includes the Great Lakes and follows the valleys of the large rivers, but it is eventually coastwise. It winters occasionally in the interior, where it can find large bodies of open water and is sometimes caught by a sudden freeze when it perishes on the ice or snow for lack of food. The principal winter home of the species, however, is at sea and it extends along practically the whole of both coasts of the United States.

DISTRIBUTION
Breeding range: Northern parts of the Northern Hemisphere. In North America east to northern Greenland (Floeberg Beach, latitude 820 27′ N., Bowdoin Bay, and Whale Sound), Labrador, and Newfoundland. South to New Brunswick (Bay of Fundy, formerly), central Quebec (Point de Montz), central Keewatin (Fort Churchill). southern Mackenzie (Great Slave Lake and perhaps somewhat south of that latitude), Queen Charlotte Islands (Graham Island), and southern Alaska (near Sitka; Glacier Bay; Prince Wilham Sound, Cordova; Cooks Inlet, Seldovia). West to the Aleutian and Commander Islands and Bering Sea. North to northern Alaska (Point Barrow and the Arctic coast), Banks Land (Mercy Bay), Melville Island, Ellesmere Land, and Grant Land (820 30′ N.). Stray birds occasionally summer in northern United States and southern Canada. Said to have bred once at Pittston, Pennsylvania.

In the Old World: East to northeastern Siberia (Delta of Kolyma River, Cape Serdze, and Anadyr district) and Bering Sea. South to Saghalin Island and Kuril Islands (Paramushir and Shunishu). Southern limits of breeding range over much of Siberia and Europe very poorly defined. West to British Isles (Ireland. northern Scotland, the Outer Hebrides, Orkney and Shetland Islands). North to Iceland, Scandinavia, the entire Arctic coast of Europe and Asia, Nova Zembla, Kolguev, Spitzbergen, Franz Joseph Land, and New Siberia Islands.

Winter range: In North America principally along the seacoast. East to Maine and the Atlantic Coast States. South to Florida (Anclote River). Apparently absent from the rest of the Gulf coast. On the Pacific coast from Puget Sound region of British Columbia and Washington south to California (entire coast and two interior records). It also winters in the Aleutian Islands. Occurs in winter throughout the Great Lakes (New York, Lake Ontario; Indiana; Illinois, near Chicago; Wisconsin and Michigan). has been taken once in Arizona in winter (near Tucson), and during migration stragglers sometimes occur in Missouri, Iowa, Nebraska, Idaho, and Montana.

Old World birds winter from the British Isles south to Spain and Portugal, the Mediterranean, Black, and Caspian Seas, and from Japan to southeastern China and Formosa.

Spring migration: Northward along both coasts of North America and in the interior. South Carolina: April 8. New York: Last of March to June 1. Connecticut: April 30 (latest). Rhode Island: April 27 (average departure), May 22 (latest). Southern Greenland: Sukkertoppen, June 2. Northeastern Greenland, Stormkap, June 8 and 11. Indiana: May 4 and 11 (latest). Michigan: March 3 to April 25 (occasionally May). Alberta: Lily Lake, May 2. Mackenzie :Athabaska Lake, June 2 (earliest); Great Slave Lake, June 10 (earliest) ; Mackenzie River, near Nahanni River, June 3 (earliest). Yukon Territory: Forty Mile, June 15. California: Santa Barbara, April 27. Washington: Lapush, June 11 (latest). British Columbia: Vancouver Island, June 4 (latest). Southeastern Alaska: Forrester Island, May 11; Admiralty Island, May 1. Northwestern Alaska: St. Michael, May 12 to 20 (earliest); Point Hope, May 17 (earliest); Point Barrow, June 5 (earliest); Demarcation Point, June 12. Banks Land: Soon after June 1. Melville Sound: June 16.

Fall migration: Southward starting in September. The last individuals were noted in northeastern Siberia: Great Liakoff Island, September 9. Alaska: Point Barrow, August 16 and September 17; St. Michael, September 15 to 20. Wellington Channel: August 28. Melville Peninsula: Winter Island, September 14. Northwestern Greenland: Early August to October. Northeastern Greenland: Stormkap, September 4. Yukon Territory: Teslin Lake, October 21.

Mackenzie: Fort Franklin, September 22 and 27. Keewatin: Knee Lake, September 9. Birds arrive in Massachusetts: October 1 to 17. New York: September 19 (August 24, earliest). New Jersey: Delaware River, October 20. South Carolina: Mt. Pleasant, October 15. idaho: Lake Coeur d’Alene, October 6. California coast: Arrives in September.

Egg dates: Greenland and Iceland: 33 records, May 10 to July 21; 16 records, June 6 to 21. Mackenzie: 15 records, June 10 to July 25; 8 records, July 1 to 6. Northern Alaska and Siberia: 11 records, June 6 to July 15; 6 records, June 26 to July 4. Hudson Bay and Labrador: 8 records, May 30 to July 5; 4 records, June 6 to 19.