(Credit: U. S. Geological Survey)

Common Loon - Gavia immer

Identification Tips:

  1. Length: 24 inches Wingspan: 58 inches
  2. Sexes similar
  3. Large diving bird with long body that rides low in the water
  4. Large bill is straight, tapers to a point, and is held horizontally
  5. Feet set far back on body, and trail behind body in flight
  6. Upperwings wholly dark in flight

Adult alternate:

  1. Black bill
  2. Black head
  3. Black neck with white markings
  4. White chest and belly
  5. Black back with white checkering and spotting

Adult basic:

  1. Pale gray bill
  2. Gray-brown cap, forehead, nape, hindneck and back
  3. White face, eye ring, chin, throat, foreneck and belly
  4. Jagged border between white foreneck and dark hindneck

Immature:

  1. Like basic-plumaged adult but often with paler bill and white scalloping on back

Similar species:

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.