Antarctic tern
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Vital Statistics
Scientific name: Sterna vittata
Appearance: The bill is bright red and the feet and legs, orange/red. The head is black during the summer, but in the winter months it is streaked with white.
Length: approximately 40 cm
Wingspan: 80 cm
Weight: approximately 100- 180g, males are heavier
Breeding age: Most birds are breeding by age 2
Breeding frequency: Annual
Breeding season: Breeding birds arrive in late October. Egg laying commences in mid January, with eggs hatching in February and fledging in April.
Longevity: Unknown for Heard Island
Foraging Statistics
What do I eat? Antarctic terns are gregarious, fishing in flocks of up to several hundred birds just beyond the surf zone. They feed on small fish and various crustacea. Antarctic terns also scavenge in the intertidal zone for stranded littoral organisms and do not feed on land. At Heard Island, Antarctic Terns have been seen foraging in coastal marine lagoons.
What eats me? Adult Antarctic terns co-operate to defend their colonies. However, Subantarctic Skuas and Kelp Gulls still occasionally manage to take eggs or chicks from unattended nests in colonies.
Range trip length: Mostly feed close to shore in the kelp-zone and often in heavy surf. Non-breeding range is not completely known, but it is believed that Heard Island terns migrate to southern Africa in winter.
Distribution & Abundance
Distribution: Antarctic Terns breed at Tristan da Cunha, Gough Island, Iles Kerguelen, St. Paul and Amsterdam Island, South Georgia, South Sandwich Islands, South Orkney Islands, South Shetland Islands, the Antarctic Peninsula, some New Zealand subantarctic islands, Macquarie Island and Heard Island. The birds generally breed among rocks, such as on rocky shores, terminal moraines and cliffs, and sometimes among low-lying vegetation.
Abundance: The population on Heard Island is estimated at 200 breeding birds. There is currently no data to indicate popluation trends.
Conservation Status
The species is a listed threatened (vulnerable) and marine species under the Environment Protection and Biodiversity Conservation Act 1999.
The species is covered by a National recovery plan for ten species of seabird currently in preparation, and the Action Plan for Australian Birds 2000.
General Comments
Individuals are highly sensitive to human disturbance and will readily abandon their nest if approached too closely.
