Cormorants have hooked bills. Western, Clark's and Red-necked Grebes have thinner bills marked with yellow and show white in the wings in flight. Red-throated Loon has a thinner, upturned bill that it carries above horizontal. In basic and immature plumages its back is spangled with white spots and its head and neck are pale gray, with a straighter line of division with the white foreneck. Pacific Loon has a shorter, thinner bill, a sharp line dividing the pale foreneck and dark hindneck and no white around the eye. The rare Yellow-billed Loon is similar in all plumages, but has a bill that is beveled upwards at the tip and a blockier head, and is entirely yellow beyond the gonys. In basic and immature plumages, the head and hindneck are paler with a darker spot to the auriculars, and back has more pattern.