In non-breeding plumage the crown is largely white, mottled black and the bill is blackish at the base and tip. Immature Fairy Terns are similar to non-breeding adults. Young birds are similar to immatures, but their upperwing coverts and mantle are mottled grey and brown.
Average size is 24cm and average weight is 40 grams.
The Fairy Tern occurs along the coast from Dampier Archipelago, Western Australia, around the southern coastline to Tasmania and Victoria. It is a vagrant to the east coast.
Fairy Terns also occur in New Zealand and New Caledonia.
Habitat: Coastal, Island
Fairy Terns mostly occur on sheltered coastal beaches, inshore and offshore islands, sheltered inlets, sewage farms, harbours, estuaries and lagoons.
They also inhabit both freshwater and saline wetlands, and sometimes near-coastal wetlands, including lakes and salt-ponds.
Behaviour
Fairy Terns usually nest above the high-tide mark on sandy beaches, spits or ridges, laying one or two speckled eggs in a shallow scrape in the sand, which is sometimes lined with small shells or seaweed.
The fluffy chicks are brooded by the adults for six days, after which the young are mobile, sometimes moving hundreds of metres from the nest to shelter under beachcast flotsam.
These young birds are fed on small fish which have been caught in shallow, inshore waters.
Large flocks of Fairy Terns have been seen in north-western Australia, with such flocks containing up to three thousand birds, and one flock was estimated to comprise 15,000 birds. Elsewhere, their flocks are much smaller, generally up to 50 birds.
Movements of the Fairy Tern are complex, with some populations being migratory and others partly migratory. The relationship between breeding and non-breeding ranges is not known.
South-western Australian populations are migratory, though their non-breeding range is not known, but is thought to include the western Kimberley coast.
Feeding
Fairy Terns feed almost entirely on fish. Plant material, crustaceans and gastropods (snails) have been found in their stomachs, but almost certainly had been eaten by the fish they had caught.
Fairy Terns catch fish by plunging in shallow water, and may dive from heights of up to 5m. They briefly hover on rapidly beating wings with their bill pointing downwards, then dive at angles of 60°–90°, with their wings held in a steep ‘V’ before plunging into the water, then becoming airborne again after a few seconds.
Fish are swallowed head first.
Breeding
Fairy Terns breed in colonies which are occasionally large (though in New Zealand they nest solitarily).
The nest is a shallow scrape in sand, sometimes rimmed with small pebbles, shell fragments, gravel or seaweed. Nests are usually on sandy beaches, or sometimes in sandy patches among rocks or low vegetation or, occasionally, on banks of seaweed.
The breeding season is September–January. They nest once per season, laying up to three eggs, though usually two. Both sexes share incubation, which lasts for 21 days, and care for the young. The breeding season is September–January.
Conservation
