It has a slender body with a black cap and a white bluish-gray plumage. The bill and legs are yellow, but in winter its black cap turns white and the bill and legs turn black. Terns mostly nest by the seashore, by estuaries or in marshland.
修長的身軀，戴著黑色的「禮帽」，身著白色與青灰色的羽衣，嘴與腳為黃色，冬季時，黑色頭羽會逐漸褪換為白色，嘴、腳則轉為黑色。