Arctic Terns

antarctic tern

 

Description & Characteristics:

The Arctic tern has webbed feet, the tail is long and forked, the legs are short and red, and the head is rounded and white with a black cap.
Females lay one or two brown-speckled. Both parents care for the eggs and feed the hatchlings.

Accomplished flyers and long-distance travelers, terns are a familiar sight in most coastal waters around the globe. Three species of tern may be commonly seen in the Southern Ocean: Arctic terns, Antarctic Terns, and Kerguelen Terns. Away from land, terns seen at sea are most likely to be Arctic terns, which are migrants from the Northern Hemisphere. Antarctic and the less common Kerguelen terns breed mainly on southern islands in the subantarctic, the former being found on the Antarctic peninsula, as well. Antarctic terns migrate several thousand miles each winter to feed in coastal South African waters.

The Antarctic and Kerguelen terns are very similar in appearance and size to their Arctic cousin. In fact, distinguishing Antarctic from Kerguelen terns can perplex even the most knowledgeable birders. All three tern species are slender, long-winged grey and white birds. They have bright red bills, orangish-red legs and feet. Their heads are donned with conspicuous black caps which may be streaked with white during the summer months. Adult Antarctic terns are approximately 14 inches in length and have a wingspan of up to 3 feet.

Terns are quite gregarious in nature, fishing in flocks of up to several hundred birds within sight of land just beyond the surf zone and often within the kelp bed zone. They feed by swooping down and making shallow dives into the water to snatch prey. Principal diet includes small fish and various crustacea, krill probably being the most important and abundant. Antarctic terns also scavenge in the intertidal zone for stranded organisms.

Antarctic terns return to breed in loose colonies adjacent to coastal waters in September and October. They lay two to three mottled eggs in open, shallow, pebble or shell-lined scrapes on the ground. There are usually no more than 40 widely distributed nests in any one locality. The nests are difficult to see as the eggs and chicks are highly camouflaged. Fledging of the chicks occurs between January through to May. The parents attend their young for several weeks after fledging, occasionally feeding their chicks.

Adult Antarctic terns cooperate to defend their colonies from other predatory bird and mammal species, although skuas and Kelp gulls still occasionally manage to take eggs or chicks from unattended nests.

Antarctic and Kerguelen terns have a lifespan of approximately 20 years.

 

  Did you know?


- Arctic terns breed in the tundra of the far north, but fly halfway around the globe--over 12,000 miles--to the edge of the Antarctic ice pack each year--a journey of over eight months.

- Since Arctic terns go from boreal summer to austral summer, they enjoy more daylight than practically any other species of animal.

- Arctic terns have a life span of about 20 years and in that time some individuals may have travelled over 200,000 miles!