Last Caspian of the season?

Today's heavily worn second-calendar-year Caspian Gull at Rainham.

I put in a brief gulling stint in the Rainham area this morning, but numbers of birds are well down now and the effort produced little reward. Best in class was this second-calendar-year Caspian Gull, badly in need of a new set of feathers. Five Yellow-legged Gulls added some interest, but otherwise the action was new migrants rather than attention-grabbing larids - Sand Martin, Barn Swallow, Northern Wheatear, singing male Common Whitethroat and two Common Terns on the river were all noteworthy. Probably time to draw a line under another gulling season on the Thames, and focus attention on the potential spring brings.

It's getting late for Caspians in London - how long will this bird linger?