Photo 9: LBBG sub-adult?, September 17 2001, Vuurtorenvlakte Maasvlakte, the Netherlands.

An individual hard to age correctly; the upper-parts are typical adult-like grey and the under-parts all white. Although the bare parts are adult-like as well, the bill shows a faint brown spot on the upper mandible. Also, the very fresh tertials have tips confined to the inner web, while the older tertials have no white tip at all. P5 is full-grown, p9 is still old and doesn't have a mirror. These features may point to immaturity, but may be signs of adult winter plumage as well.