A pair of Black-naped Terns resting at a cavity of a steep rock cliff on Koh Si Chang, an island in Chonburi Province.

The face, breast and crown are white, the back and wings silvery greyish, and the belly a pale greyish-white. They have black eye-stripes that connect to the black patch on the nape.

When one bird turns its head, the white crown and distinctive black triangular nape become clearly visible.