This was the first bird we came across, a small, very pale Thayer's with solid dark centered tertials, uniform coloration, small all black bill , and light edging to the primaries. This bird and one of the Iceland Gulls played chase with a small dark object and we were able to compare wing patterns while they were in the air. The bird was so light I thought at first it might be a Kumlien's but the solid un-barred tertials, I believe rule that out but..........