One of the most amazing migratory birds, the Arctic tern covers a 25,000-mile roundtrip journey between its breeding grounds and wintering grounds, flying for up to eight months nonstop each year. In its lifetime of 30 or more years, one Arctic tern may migrate the equivalent of flying from the Earth to the Moon and back.
- Bill: Short for a tern, thick, deep red to red-orange, black in winter
- Size: 16-17 inches long with 31-inch wingspan, long tapered wings, very short legs, long deeply forked tail, slender build
- Colors: Black, white, red, gray, brown, buff
- Markings: Genders are similar and in breeding plumage have a solid black cap and nape that contrasts sharply with white auriculars. The throat is pale gray, and the underparts are a stronger gray. The back and wings are medium gray, with a black trailing edge on the primary feathers that shows in flight. The rump is white, and the tail is white with gray outer feathers that are slim and show as streamers. The legs and feet are deep red. In winter, the forehead turns white and the bill, legs and feet are black.
Juveniles look similar to adult non-breeding birds but are more brown on the forehead and have grayish, brownish or buff scaling along the body and wings.
Species is monotypic.
Fish, crustaceans, marine invertebrates, insects (See: Piscivorous)
Habitat and Migration:
These terns prefer open, rocky tundra or meadow habitats, as well as coastal beaches, tundra marshes and islands. During the breeding season, they are found throughout the Arctic, stretching from Alaska through the Yukon, Northwest Territories and Nunavut to coastal Quebec, Newfoundland and Labrador and Nova Scotia, as far south as Maine. Along the Pacific Coast of North America, Arctic terns can be found as far south as the northwestern corner of British Columbia. These birds are also found in similar regions of Europe and Asia, including Greenland, Iceland, Scandinavia and Russia.
During migration, Arctic terns stay far out to sea, and in winter they inhabit the Antarctic Ocean and Antarctica, stretching as far north as the southern tip of South America, South Africa and occasionally Australia.
Vagrant sightings are regularly recorded, particularly for terns blown inland or much further south, or north in the non-breeding season, than expected by storms or unseasonal weather and wind patterns.
These birds have a harsh, raspy call that is a rough “keeee-EEEEER” with a higher pitch on the second part of the call. Other calls include a thick chatter.
These birds are skilled fishermen and will hover 30-40 feet above the surface of the water while scanning for prey before plunging into the water to catch their next meal. Opportunistic and intelligent, they will also follow fishing vessels looking for easy prey or handouts. At the nest, Arctic terns can be aggressive and will chase and attack intruders, all the while vocalizing loudly.
These are monogamous birds that may nest alone or in colonies. Both male and female of a mated pair work together to build a shallow scrape nest lined with grass or shells. There will be 1-3 eggs per brood and only one brood is laid per year. The oval-shaped eggs may be buff or pale olive in color with dark blotches typically concentrated near the larger end.
Both parents incubate the eggs for 20-24 days, and the young chicks covered in mottled down will leave the nest within just a few days to hide nearby. The fledglings will make their first flight when they are 22-28 days old, but they will remain near the parents for feeding for an additional 1-2 months.
Where their ranges overlap, Arctic terns occasinally hybridize with roseate terns, Forster’s terns and common terns.
Attracting Arctic Terns:
These are not backyard birds but they can be seen on quiet, rocky beaches within their typical range. During migration, pelagic birding trips may come across Arctic terns well out to sea.
In the late 1800s and early 1900s, Arctic terns were hunted for their tails as part of fashion trends for ladies’ hats, but since that time their numbers have recovered substantially. Throughout most of their range, these birds have stable population numbers, but in the southern parts of their breeding range, numbers are declining. Protecting their breeding sites from feral cats, dogs or unwary beachgoers can help further safeguard these birds.