Terns are smallish birds with a prominent forked tail and sharply pointed wings. They are noisy and gregarious and prefer areas around water bodies, whether coastal, rivers or reservoirs.
They feed mainly on fish and crustaceans, foraging over water to get their food. The bird may suddenly dives into the water to catch fish or hovers above to suddenly plunge down. Sometimes it may fly close to the water to swoop down whenever it spots a prey. Certain species may sit or swim on the water surface to pick up food items from the water surface of just below. Many species also indulge in piracy to get their food, especially when male birds bring fish to the female during courtship feeding.
Terns have also been known to hawk insects on the wing, especially when there is a termite hatch.
The Little Terns (Sterna albifrons) that Meng and Melinda Chan observed last year around the Neo Tiew Road area were mostly interested in foraging for fish in the Kranji Reservoir. The birds were mostly flying above the water surface, hovering around an area once they spot fish, to suddenly dive down and make a catch (see images below). With the fish firmly in its beak, the tern would fly off to land to complete its meal.