Yellow-billed loon Gavia adamsii

Identification Tips:

• Length: 25 inches Wingspan: 60 inches
• Sexes similar
• Immature like basic-plumaged adult
• Large diving bird with long body that rides low in the water
• Large bill is beveled upwards at tip and is held slightly above horizontal
• Feet set far back on body, and trail behind body in flight
• Upperwings wholly dark in flight

Adult alternate:

• Yellow bill
• Black head
• Black neck with white markings
• White chest and belly
• Black back with white checkering and spotting

Adult basic:

• Pale bill
• Gray-brown cap, forehead, nape, hindneck, and back
• White face, eye ring, chin, throat, foreneck, and belly
• Dark auricular spot

Similar species:

Cormorants have hooked bills. Western, Clark's, and Red-necked grebes have thinner bills and show white in the wings in flight. Red-throated Loon has a thinner, upturned bill. 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 Common Loon is similar in all plumages, but has a bill that is straight at the tip and a less blocky head, and an entirely dark culmen beyond the gonys. In basic and immature plumages, the Common Loon's head and hindneck are darker without a darker spot to the auriculars, and back has less pattern.

Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.