One of the highlights of my recent trip to Liaoning Province was the opportunity to see so many gulls at Jinzhou Bay (we estimated over 4,000). This number must make Jinzhou Bay one of the premier gull-watching sites in northern China (if you know of a comparable site, please let me know!). The channel of running water alongside the landfill tip was a favoured haunt of Common Gulls (Larus canus) and, over the two days I spent at this site, I saw several young birds, presumably of both the subspecies found in this area – kamtschatschensis and heinei. Here are a few images and personal comments. Please let me know if you disagree with my identification or if you have more to add.
The kamtschatschensis bird, in particular, would certainly stand out if it turned up in the Western Europe!
First winter Common Gull of the subspecies kamtschatschensis, Jinzhou Bay, Dalian, Liaoning Province. Note the dark, well marked underparts and strongly barred undertail coverts.
First winter Common Gull subspecies heinei, Jinzhou Bay, Dalian, Liaoning Province, 25 January 2012. Note the very clean, white underparts.
First winter Common Gull ssp kamtschatschensis, Jinzhou Bay, Dalian, Liaoning Province, 25 January 2012. The upperparts are well-marked and the moult of juvenile feathers seems to be later than the heinei ssp below.
First winter Common Gull ssp heinei, Jinzhou Bay, Dalian, Liaoning Province. Much cleaner, especially the uppertail, and more advanced moult, notably on the scapulars.
It’s difficult to tell from these images but, in the field, the kamtschatschensis bird appeared to be stockier with a slightly longer bill.
Second winter Common Gull, Zhuanghe, Liaoning Province, 28 January 2012. I suspect this individual is of the subspecies kamtschatschensis. Aged as a second winter due to the presence of some adult-type wing feathers, the small white 'mirror' on the outer primary (P10) and the relatively clean tail. Note the brownish fringes to some of the coverts, a good feature of second winter kamtschatschensis.
Second Winter Common Gull, Zhuanghe, Liaoning Province, 28 January 2012. Probably of the ssp kamtschatschensis. Same bird as above.