The short arctic breeding season combined with one of the longest annual migrations of any bird means the Arctic Tern is only on its breeding grounds for two or three months, and is flying much of the rest of the year. The Arctic Tern has been little studied on its Antarctic wintering grounds.
Arctic Terns are very gregarious, and nesting colonies of 10,000 to several hundred thousand birds are known. A small space around individual nests is defended, often aggressively, by the adult terns. Many nearby neighbors will join in to form a large, mobbing group if a predator approaches.
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Description of the Arctic Tern
The Arctic Tern is a slim, grayish tern with a black cap and nape, a red bill, red legs, uniformly grayish wings, and a long, forked tail.
Seasonal change in appearance
Forehead becomes white in winter.
Young Arctic Tern, feathers edged in brown and black.
Older juveniles have faint dark shoulder bar and some white in forehead, a black bill, and short tail.
Open ocean, as well as tundra lakes and coastlines.
Fish and crustaceans as well as insects.
Usually forages by plunging into the water.
Arctic Terns breed in the northernmost portions of North America and Europe and winter around Antarctica.
The extraordinarily long annual migrations of the Arctic Tern can total 25,000 miles.
Arctic Terns can live over 30 years, so migratory movements totaling over 750,000 miles by a single bird are possible.
A variety of loud, sharp calls are given on the breeding grounds, and some softer calls are given during courtship.
Common Terns are slightly stockier and have somewhat darker outer flight feathers.
The Arctic Tern uses a shallow scrape lined with plant materials.
Color: Buffy or greenish with darker markings.
Incubation and fledging:
– Young hatch at about 20-24 days.
– Young fledge (leave the nest) in 1-3 days, but remain nearby and associate with the adults for some time.
Bent Life History of the Arctic Tern
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 Arctic Tern – the common name and sub-species reflect the nomenclature in use at the time the description was written.
STERNA PARADISAEA (Brunnich)
The casual observer, fascinated by the sight of a flock of graceful terns diving for fish on the. New England coast, naturally supposes they are all of one kind, and is told they are mackerel gulls. The ornithologist enjoys the same esthetic charm in the sight, but has often the added intellectual pleasure of discovering several distinct species in the flock. Common terms are generally in the majority but arctic and roseate terns may also be seen, as well as least and black terns. It would be difficult to point out to the untrained observer the differences between the common and arctic terns, but they can be recognized with a little practice and without the use of the gun. The feeding and nesting habits, mode of flight, size, and general appearance of these two species are, however, very much alike.
The Arctic tern breeds throughout the entire circumpolar regions as far north as it can find land, and south in this country to northern British Columbia, Great Slave Lake, Central Keewatin, Maine, and Muskegat Island, Massachusetts. It is credited by Cook (1911) with being “the world’s migration champion.” After the breeding season is over the bird repairs from the Arctic to the Antarctic regions. “What their track is over that 11,000 miles of intervening space no one knows,” says Cooke (1911).
A few scattered Individuals have been noted along the United States coast south to Long Island, but the great flocks of thousands and thousands of these terns which alternate from one pole to the other have never been met by any trained ornithologist competent to learn their preferred path and their time schedule. The Arctic terns arrive In the far north about June 15 and leave about August 25, thus stayIng 14 weeks at the nesting site. They probably spend a few weeks longer in the winter than in the summer home and, if so, this leaves them scarcely 20 weeks for the round trip of 22,000 miles. Not less than 150 miles In a straight line must be their daily task, and this Is undoubtedly multiplied several times by their zigzag twisting and turning in pursuit of food.
The Arctic terns have more hours of daylight and sunlight than any other animal on the globe. At their most northern nesting site the midnight sun ha~ already appeared before their arrival, and It never sets during their entire stay at the breeding grounds. DurIng two months of their sojourn in the Ant. arctic they do not see a sunset, and for the rest of. the time the sun dips only a little way below the horizon and broad daylight continues all night. The birds therefore, have 24 hours of daylight for at least eight months in the year, and during the other four months have considerably more daylight than darkness.
Spring: The most southern breeding place of the Arctic tern seems to have been Muskegat Isle, off Nantucket. Mackay (1897) gives the earliest date for the arrival of terns at this island as May 3, in 1897. The day before no terns were to be seen, while on the third they arrived “in large flocks, thousands dropping from the sky when they were first observed.” The larger part of these were common and roseate terns, but he found a few Arctic terns breeding. When I visited this island in 1913 about 20,000 common terns, 1,000 roseate terns, and 3,000 laughing gulls were breeding, and I feel fairly sure that I saw a couple of Arctic terns, so there is a possibility that they still breed there. They were found breeding at Beverly in 1846 by Cabot (1846) and at Ipswich between 1868 and 1870 by Maynard (1870). They no longer breed there. On the Maine coast the Arctic tern, like the common tern, has steadily increased in numbers under protection since its low ebb due to, the war of the milliners in the late nineties. Its chief breeding grounds there, according to Knight (1908), are Metinic, Green, Machias Seal Islands, and Matinicus Rock, where it nests with the common tern. It arrives from the south from the middle to the last of May. Its arrival on the southern coast of Labrador is at about the same time. Turner (1886) says that this tern is one of the earliest birds to arrive at St. Michael, Alaska.
The earliest date recorded was April 25,, a very early season, showing that the terns only await the movement of the sea ice to appear in any locality. They become very abundant by the middle of May.
Murdoch (1885) reports that the tern arrives at Point Barrow, Alaska, about June 10.
Nesting: The Arctic tern prefers to breed in colonies of its own species, but it is not rare to find a few common terns in these colonies or to find a colony composed largely of common terns with a few arctic terns. In Alaska they are often associated with Aleutian terns. Turner (1886) says their nests are sometimes placed within 2 feet of each other, and apparently without causing animosity between the species. Sandy or rocky islands are usually chosen, and the nests are scattered more or less thickly over the ground. Grinnell (1900) states that in Alaska he did not find the bird in colonies, as two nests were seldom within a hundred yards of each other; usually only one pair were found at a pond. Small islets were often selected, but he occasionally found this species nesting on the tundra a quarter of a mile from the nearest lake.
Nelson (1883) says:
Along both shores of Bering Sea and upon both shores of the adjoining Arctic waters this bird Is very common. It nests wherever found in this region, and occurs indifferently either in the interior along the courses of the rivers, or on the salt marshes and barren Islands on the seacoast. * * It nests on some of the sterile islands of the North, In flocks, upon the bare sandy or pebbly ground, with no trace of any artificial nest. * ï * On the eastern shore of Bering Sea I have only found it nesting singly, in pairs scattered here and there over the marshes, and in one instance three pairs were found occupying the same small Island in a lake, which is the largest number I found nesting in close proximity.
This goes to show, as he says, “that the birds’ habits vary greatly with the locality.” Hinckley (1900) found the Arctic tern nesting along the Sushitna and Kuskokwim Rivers “even in high mountain valleys.” Turner (1886) says:
They breed in the low grounds, preferably a low, damp island, such as those at the northern end of the canal. At this place hundreds of nests were discovered in 1876.
Feilden (1877) found several pairs of Arctic terns breeding in latitude 810 44′ on Bellots Island, on August 21. The land was covered with snow, and from one nest, in which was a newly hatched tern, the parents had thrown out the snow so that the nest was surrounded by a border marked by their feet 2 inches above the general level.
The Arctic tern is more inclined to omit nesting material than is the common tern, and its nest is generally merely a hollow in the ï sand, gravel, or moss or in the rocks. Occasionally a thin lining of dry grasses is used, but an elaborate nest is rarely or never seen. Turner (1886) says:
The nest Is merely a hare spot on the ground. Sometimes a few blades of grass surround the margin of the nest, but these seem to be more the result of cleaning off a bare spot than an attempt to construct a nest.
Palmer (1890), who found this the only species of tern at Funk Island, says that the eggs were laid on the bare rocks, often with broken pieces of granite or pebbles sometimes gathered from a distance arranged about them in a circle. In some cases he found bones of the great auk used in the same manner. Occasionally the eggs were laid in depressions in the gravel, among mussel shells, in crevices, amid tangled masses of chickweed 6 inches high that was dead, in a circle 5 inches about; also in depressions in dead grass as if a mouse’s nest had been appropriated. McGregor (1902) says:
A typical nest was a depression 1 inch deep by 5 inches in diameter, lined with dry grass and weed stalks.
Parry (1824) says: The nest in which the eggs are deposited, and each of which generally contained two, consisted merely of a small indentatiod In the ground, without any downy feathers or other material.
[Author’s NOTES: Eggs: The Arctic tern raises only one brood in a season and the set usually consists of two eggs; three eggs are often laid, but larger numbers are very rare. A very large majority, or nearly all, of the sets collected in the far north consist of two eggs. The eggs can not be distinguished from those of the common tern by any constant or even prevailing character, though they seem to average a trifle darker in color and more rounded in shape, which varies from ovate to rounded ovate. The ground color varies greatly; in the darkest eggs it is “Brussels brown” or “Dresden brown”; in others it is ” Saccardo’s olive,” “ecru olive,” or ” dark olive buff”; and in the lightest egg “water green” or “pale olive buff.” The eggs are more or less irregularly spotted or blotched with the darker shades of brown, such as “chaetura black,” “bone brown,” or “chestnut brown,” and often there are underlying spots of various shades of “brownish drab” or “ecru drab.” The measurements of 123 eggs in the United States National Museum average 41 by 29.5 millimeters; the eggs showing the four extremes measure 46 by 32 and 37 by 27 millimeters.
Plumages: The period of incubation is probably about 21 days. Both sexes incubate. The downy young of the Arctic tern may be distinguished from that of any other American tern by the black or dusky frontal space, which includes the lores and extends across the base of the bill. This dark area matches in color the dark-colored throat, which varies from “dusky drab” to nearly black. The breast is pure white, becoming more grayish posteriorly. The upper parts show at least two distinct color phases, both of which are sometimes found in one brood. In the brown phase the head, back, and wings vary from “cinnamon” to “pinkish buff.” In the gray phase these parts are “pale drab gray” or “pale smoke gray,” shading off gradually into the white or paler color of the under parts. In both phases the head is distinctly spotted and the back is heavily mottled or variegated with “fuscous” or black; the markings are usually blacker in the brown phase than in the gray. The plumage appears first on the wings and scapulars, then on the sides of the breast, and the last of the down is seen on the head.
The juvenal plumage is fully acquired by the time the young bird is fully grown. In this plumage the forehead and crown are grayish, the latter mottled with black, which increases on the auriculars and occiput to practically solid black. The back and wings are “deep gull gray,” each feather of the back, scapulars, and wing-coverts being edged with pale buffy, with a subterminal dusky band and fine dusky sprinkling; these markings are most conspicuous on the scapulars. The tertials, secondaries, and inner primaries are broadly edged with white. There is considerable dusky and some pale buff near the ends of the tail feathers. The under parts are white, washed with pale brownish tints on the throat, breast, and sides. This plumage seems to be worn until the birds leave in September, but it is probably partially molted in the fall to produce the first winter plumage, which is similar to the adult. Subsequent molts and plumages are apparently similar to those of the common tern, including the portlandica plumage.]:
Food: The food of the arctic tern is the same as that of the other terns found in the same region, and consists chiefly of small fish, such as capelins, and sand eels or sand launces, and the fry of larger fish. Small crustaceans are also eaten. The method of capture is the same as in the case of the other terns. Scanning the water with down-turned head and bill from a height of 30 or 40 feet, this little tern falls with the speed of an arrow, strikes the water with a splash, and often disappears completely below the surface in order to capture its prey. As it rises from the water it shakes its plumage vigorously, and the fish may be seen hanging from the bill. Occasionally it throws the fish into the air either for pure fun or to get a better hold. Sometimes the tern drops the fish but catches it again before it has fallen more than a yard or two. The presence of the fish in the bill never interferes with the capacity of the bird to scream or cry out. In fact the fish bearer generally screams constantly as if to announce its success in the chase.
Behavior: I have known them to fly directly at my head to within a few feet, when they suddenly swerve upwards. As they dart down they emit in their rage a rapidly repeated and vibratory tut tut or kik, kik, kik, followed by a piercing, screaming tearr, which is shriller than that of the common terns and ends in a rising inflection, which has been well characterized by Brewster (1883) as “sounding very like the squeal of a pig.” He says “the bird also has a short, harsh note similar to that of Forster’s tern.” Grinnell (1900) says that the teasing cries of the young “closely resemble the usual note of the white-throated swift in California.”:
The Arctic tern, like the common tern, kittiwake, and others, is frequently harassed by the various species of jaegers, and after much twisting and turning is forced to drop the fish, which is at once snapped up by its pursuer. Although terns frequently quarrel among themselves, the various species often rest peaceably together. The former pernicious practices which led to the almost complete annihilation of terns for millinery purposes have already been described at length under the common tern. It is fortunate that these days of slaughter are passed. The increase of terns along the New England coast in the last 10 or 15 years has been very marked. In regions where game laws are but little understood or regarded the killing of such easy victims as terns still goes on. I have seen on the Labrador coast both common and Arctic terns that had been shot to feed captive black foxes.
Dutcher (1903) quotes Norton in regard to mortality among the young of the Arctic tern on the Maine coast as follows: Abundant as they were living, I noticed quite an extensive mortality among the downy young, and their decaying bodies were scattered over the Island. There was no visible cause, but two things suggested themselves – one an epidemic; the other that the damp, cold summer just passed had not supplied sufficient warmth and sunlight to keep them from being chilled.
In another place (1905) he quotes Capt. James Hall, of Matinicus Rock, Maine, as expressing ” the belief that food is scarce and starvation is the cause of much death late in the summer.” Palmer (1890) says:
In no other species of bird with whose breeding habits I am familiar has nature been so prodigal of life as in the case of the young terns on Funk Is~and. The surface of the granite rock of the island has been corroded by time and the elements to such a degree that many shallow depressions have been rotted as it were. These have been filled with water by the abundant rain and were veritable death traps to the young ferns. Many of them leave the nest when a few days old and wander about. Numbers are thus lost among the rocks and drowned while trying to get back to their parents. This explanation seems to me to account for the numbers of dead young found In tbe pools.
It is possible, however, there may be some other explanation, for young terns are expert swimmers. :
Breeding range: Circum polar. In North America, south on the Atlantic coast to Massachusetts (Muskeget Island) ; in the interior south to the Gulf of St. Lawrence (Magdalen Islands), southern Quebec (Point de Monte), southern Mackenzie (Great Slave Lake), southern Yukon (Pelly Lakes and Lake Tagish), and southeastern Alaska (Taku Inlet). The coasts and islands of Bering Sea south to the Aleutian and Commander Islands. North to the Arctic coasts of North America and in the Arctic Archipelago north to 820 north latitude in King Oscar Land, Grant Land, and northern (ireenlancl. In the Eastern Hemisphere, north to 820 north latitude. South in Europe to 500 north latitude; and in Asia to 520 north latitude.
Breeding grounds protected in the following national reservations: In Alaska, Aleutian Islands, as Amchitka, Near Islands, Range I sland, Semichi. Winter range: Antarctic Ocean, south to 740 south latitude, Weddell Sea, and probably Ross’s Sea (off Victoria Land, 760 52′ 5). Northern limit of winter range unknown.
Spring migration: Northward along both coasts, often well out at sea. Early dates of arrival: Massachusetts, March 20 to 31; Davis Strait, 660 north, April 12; Wellington Channel, June 13; Greenland, 810 30′ north, June 16; Washington, Crescent Lake, April 15; Alaska, St. Michael, April 25 to May 16, and Demarcation Point, May 31.
Fall migration: Southward over same routes. Early dates of arrival: California, Point Pinos, August 4; Peru, Santa Lucia, September 19; Chile, Arica, October 4; Argentina. Mar del Plata, October 21. Late dates of departure: Greenland, 810 30′ north, August 26, and Disco, September 5; Wellington Channel, August 29; Franklin, Winte” Harbor, September 5; Keewatin, York Factory, August 28; Ungava, Koksoak River, September 15; New York, Saratoga, October 8; Massachusetts, Cape Cod, October 24 to November 9; Alaska, Point Barrow, September 9; British Columbia, Okanagan Landing, October.
Casual records: Accidental in the interior, where records are none too well established. Wisconsin records (Lake Koshkonong, breeding, June 1891; Kelley Brook, September 21, 1897, and Milton, May 27, 1899) seem to be authentic. Recorded twice in Hawaii (May 9, 1891, and April 30, 1902).
Egg dates: Northern Mackenzie: Thirty-two records, June 14 to July 16; sixteen records, June 23 to July 5. Maine and Nova Scotia: Twenty-six records, June 8 to July 21; thirteen records, June 15 to 23. Alaska: Twenty-two records, May 4 to July 1; eleven records, June 14 to 27.