Identifying Loons

The only loon reported in the Brazos Valley is Common Loon. But other parts of Texas have occasional reports in winter of Pacific and Red-throated Loons and even Yellow-billed Loon a few times. Breeding plumage loons are fairly easy to identify, but wintering birds are a challenge. There is no birding area in the Brazos Valley where you can count on finding a loon. Irregular sightings have usually occurred on the big lakes, e.g., Gibbons Creek Reservoir. Interestingly, the only sighting in Robertson County was at a small residential lake only a couple dozen acres in size.

Decision Tree for Identifying Winter Loons

Bill and head position?
    = tilted slightly up
       Bill shape & color?
           = thick & yellowish.... Yellow-billed Loon
           = thin & gray.... Red-throated Loon
    = held level
       Bill shape & color?
           = thick & dark.... Common Loon
           = thin & dark.... Pacific/Arctic Loon

Other field marks

Yellow-billed Loon - dark, white mark behind eye contrasts to light face; longer bill than Common Loon; browner back than Common Loon; crown peaked in front and back; accidental in Texas.

Common Loon - white notch on neck; white throat and face encircles eye; steep forehead; crown peaked at front only.

Pacific/Arctic Loon - smoothly rounded head; brown crown and nape contrast to white throat and foreneck; thin brown necklace extends around white throat; brown cap includes eye, unlike Common Loon; crown and nape lighter than back.

Red-throated Loon - smoothly rounded head; white face includes eye, but is more sharply defined than Common Loon; back is spotted compared to Common or Pacific/Arctic Loons; head paler than back and paler than other winter loons.