153855 Common Tern Sterna hirundo L 35cm. Similar to Arctic Tern but separable with care. Sexes are similar. Adult in summer has grey upperparts, black cap and whitish underparts. Compared to Arctic, note black-tipped orange-red bill, longer red legs, and paler underparts. In flight from below, only inner primaries look translucent and wings have diffuse dark tip. Non-breeding plumage (sometimes seen in late summer) is similar but has white on forehead and dark shoulder bar; bill and legs are dark. Juvenile has white underparts, incomplete dark cap and scaly grey upperparts; in flight from above, leading and trailing edges of inner wing are dark. Voice Utters harsh kreeear call. Status Widespread summer visitor, commonest on coasts; also nests on flooded gravel pits and reservoirs. Widespread coastal passage migrant.