Seven years ago, Rich Bonser and I saw a yellow-ringed juvenile Yellow-legged Gull at Rainham Tip. That bird came from a rooftop colony in Frankfurt (a bit more about it here) and, until this weekend, it was the only ringed individual of the species that I've seen in Britain.
So it was interesting that seven years on, almost to the day, a ringed juvenile Yellow-legged at Erith Pier proved to be German. This time the bird was wearing a red band marked '92T' (rather than the usual yellow of German birds), signalling that it emanated from a different area to our usual flow of Caspian and Herring hybrids that we tend to see from early autumn onward.
The bird showed a few interesting features, not least the pale underwing and a harsh call, reminiscent of Caspian Gull (but probably not as harsh as that species), although otherwise looked like a Yellow-legged. Nonetheless, knowing that it was likely from south Germany, the possibility of mixed heritage always looms large and I was keen to find out more.
A bit of research and rapid responses from Martin Boschert and Kirsten Krätzel established that the bird had been ringed as a nestling on 18 May 2019 at a colony on an island in the Danube River near Straubing, Bavaria, in south-east Germany. This colony is almost exclusively Yellow-legged Gulls, although the odd pair of Caspian Gull has nested since 2016 and some single adult Caspian (and apparent hybrids) are present in the breeding seaon. However, no hybrid pair has yet been recorded at the colony, so it's fairly safe to assume that this is a pure Yellow-legged Gull.
The bird was present on both Saturday and Sunday over the weekend among good numbers of Yellow-legged Gulls – Rich and I managed at least 45 between us from the pier on Sunday.