Common Tern

Sterna hirundo

The Common Tern (Sterna hirundo) is a bird in the Laridae family. It typically measures 31-35cm in length. Its conservation status is Least Concern.

Length	31-35cm
Weight	120 g
Lifespan	up to 33 years
Family	Laridae
Conservation status	Least Concern

Appearance of the Common Tern

The Common Tern resembles the Arctic Tern, but some differences include the reddish-orange bill with a black tip, the paler underparts and the proportionally longer red legs. In summer the upperparts are silver-grey, it has a dark cap, and when flying the tips of the underwing feathers are dark and there's a section on the wings that can appear almost transparent. The longest flight feathers grow darker as summer progresses, appearing as a dark wedge shape. Winter plumage is similar, but the forehead whitens leaving a black bar and the bill and legs darken. Juvenile birds are white underneath, they have a partially formed dark cap, the upperparts are scaly-looking and grey, and the back is ginger. The bill is fleshy in colour or yellowish and it has a dark tip which becomes more prominent over the summer.

Where does the Common Tern live?

Breeding grounds are beaches of sand or shingle, or on craggy seashores. Feeding is usually done on inshore waters like lakes and rivers. Prefers warmer sea waters when not breeding.

Common Tern behaviour

Appears strong in the air, particularly when compared to other terns. Breeds colonially and frequently socialises in flocks. When flying in search of fish, the bill is angled downwards and this tern may rise in the air before diving, often with a hover before the change in direction. Sometimes carries fish in its bill, presumably to feed hatchlings or as an offering of courtship.

What does the Common Tern eat?

Mostly eats fish such as herring, sprats and sand eels. Fresh water diet includes roach, perch and minnows.

Common Tern breeding & nesting

Breeding begins in May when the female lays 2 or 3 well-camouflaged eggs. Both adults incubate these for 21-22 days, and hatchlings depart the nest after 3-4 days, though they stay hidden in close proximity to the nest. They learn to fly at about 22-28 days old but are not completely independent for 2 or 3 months.

Common Tern population

This bird is a summer visitor with a large distribution, and it is also a common passage migrant. It departs the region in November and December to head south to West Africa where it winters. A few birds go to Spain and Portugal. Approximately 12 000 pairs breed in the UK and more than 3 500 in Ireland.

How to spot the Common Tern

Due to the commonality of this bird, it can regularly be found by the coast or on inland expanses of freshwater, particularly in the south and the east of England. However these birds are less common in south-west England and Wales, with the exception of Anglesey.