Bill moderate; red, the tip black: legs red: tarsus nine lines and a half: tail very much forked; as long as, or a little shorter than, the wings.
S. Hirundo, Temm. Man. d'Orn. torn. ii. p. 740. Common Tern, Mont. Orn. Diet, & Supp. Bew. Brit. Birds, vol. ii. p. 185. Selb. Illust. vol. ii. p. 468. pl. 90. f. 1.
Entire length thirteen inches six lines: length of the bill (from the forehead) one inch seven lines and a half, (from the gape) two inches two lines; of the tarsus nine lines and a half; of the tail four inches six lines; from the carpus to the end of the wing ten inches four lines: breadth, wings extended, two feet six inches eight lines.
(Summer plumage) Forehead, crown, and long occipital feathers, deep black; hind part of the neck, back, scapulars, and wing-coverts, bluish ash: all the under parts white, the breast and belly faintly tinged with ash-colour: quills ash-gray passing into dusky brown at the tips, with a large oblong white space on their inner webs: tail whitish; the outer webs of the two exterior feathers dusky ash: bill red, passing into dusky at the tip: feet bright red. The winter plumage differs simply in having the forehead and crown of a more dull black. (Young of the year). Forehead and anterior part of the crown dirty white; rest of the crown towards the occiput marked with large dusky spots; the long occipital feathers brownish black with whitish tips: rest of the upper parts dull bluish ash, irregularly spotted with pale reddish brown, all the feathers whitish at the tips: under parts whitish: many of the quills tipped with white: lesser wing-coverts near the top of the wing dusky gray with whitish edges: tail ash-gray, passing into white on the inner webs, and towards the tips of the feathers: bill much shorter than in the adult bird, dusky at the tip, dull orange at the base: legs orange. (Egg). Yellowish stone-colour, blotched and spotted with ash-gray and dark red-brown: long. diam. one inch eight lines; trans, diam. one inch two lines.
Common on most parts of the British coast during the spring and summer months. Retires in the Autumn. Occasionally observed inland on fresh waters. Breeds on flat shingly shores, and lays from two to four eggs. Of noisy and restless habits; constantly on wing. Food, insects and small fish. Obs. The Brown Tern of English authors is probably this species in immature plumage.