This Yellow-billed Loon Gavia adamsii
was found by Sheridan Coffey and Martin Reid in the Laguna Madre at Corpus Christi, Texas on March 25, 2006. It is not as pale as most images of young YBLOs that I can find, and the bill was grayish at the base (this is still okay for YBLO) - this bird could easily be overlooked without a close view: These first three shots were of the bird taking a few seconds break during preening, thus the head is not being held with the slight uptilt seen when the bird was swimming normally: Note the isolated dark spot at the rear of the auricular in the pics above and below: Note the position of the high-point of the back: In some lights the base of the bill looked grayish, like a Common Loon, but the distal third always looked clean yellowy-cream, with no hint of dark along the culmen. Note that this shot was taken as the bird was in the process of flattening its crown prior ro diving: I watched it dive many times, and a few seconds prior to diving it would competely flatten its forecrown, just like Scaup do: In the pic below, note the thick pale fringes to the wing coverts; these must be retained first-cycle feathers that have been protected from wear because they normally are covered by the scapulars (2nd cycle+ feathers would be either plain or would have small white spots/streaks, not fringes): In the pic below there seems to be a white primary shaft visible above the rump (I can't think of any other explanation for this white line?) - YBLO has white primary shafts, whereas COLO has brown primary shafts:
BTW here are two other birds photographed in Corpus Christi today, providing an unlikely "Triple": Glaucous Gull at the local landfill:
Clay-colored Robin at Blucher Park:
