The first step towards this is of course to adopt a patch. It'll inevitably lead to uninspiring, gull-heavy blog posts throughout the year, particularly given that Larids offer just about the only consistent point of interest in Central London, but I guess it's better than nothing ...
So, my adopted 'patch' will be the River Thames between Barnes Bridge and Craven Cottage, Fulham. This includes Leg o' Mutton (Lonsdale Road) Reservoir, where mature woods and dense patches of scrub should offer a glimmer of hope for interesting passerines at the right times of year. It'll likely end up including Barnes WWT, too, when I finally get sick of counting Herring Gulls and Cormorants on the river itself.
WWT or not, the patch fits comfortably within to the Patchwork Challenge area remit. So, I might as well give that a go too. Happily it'll qualify for the 'green' mini-league as I do all of my birding here either on foot or via bicycle. As such you can expect to find me loitering somewhere near the bottom of the table come December.
The River Thames at Barnes - the west end of the 'patch'
I identified this bird in the field as a second-winter (3cy) which, if you look at the perched shots, is fairly understandable. It was actually the presence of a green ring on its left leg which gave away this bird's age. Green XDFE was ringed as a chick at Gräbendorfer See in eastern Germany in June 2014. It has only been recorded a few times since, including at Dungeness in September 2014, and this is the first time it's been seen since summer 2015.
Actually there are a few tell-tale signs that this bird is in its fourth calendar year, but these are more apparent in flight. What is really striking is the restricted white in the outer primaries - with the restricted white mirror on p10 only, these look much more typical of a 3cy rather than 4cy bird.