Age: An apparent large white-headed gull that appears to be beyond its 1st cycle. Notice the marbled inner greater coverts and lower tertial edges. Also, there appears to be three generations of median coverts. The mid median coverts are oldest. These worn and frayed feathers are likely 2nd basic. The outer median coverts are fresher and may have come in with a later 2nd prebasic wave (along with the lesser coverts). The darker gray inner medians are very likely 2nd alternate. All in all, the upperparts do not fit a 1st cycle. It's difficult to make out primary-tip shape or patterns, but the very small and indistinct white tips to p6-p7 on otherwise black primaries are expected on 2nd generation flight feathers.
Identification: This is a four-year gull with an apparent long wing projection, prominent gape with a "frown", a dark post-ocular line, pinched in forehead, straight tubular bill with a familiar distal-black, proximal-red pattern on the tip, bluish tibia, heavy lower neck markings, and medium gray upperparts coming in. The gull in the background is a heavy-billed Western Gull giving us a very good sense of overall body size and shape. I hope by now you've settled on California Gull if you were unsure about our April quiz. Many people nailed this one without a problem this month but were tripped up by plumage/age. One final note on that, notice the very tip to the bill. In 1st cycles, the tip is typically all black, similar to that we see in many 1st-2nd cycle Glaucous.
Santa Cruz County, California. January.