Dave Jackson forwarded these images he took of a Lesser Whitethroat in his Northampton garden today. A winter Lesser Whitethroat in the UK is exceptional and most – if not all – of these are likely to be birds of one of the eastern races.
I was struggling to stretch the ID beyond nominate curruca – it’s not particularly brown above (although the 4th image in the above sequence depicts more brown), the primary projection is not particularly short and you can’t see the extent of white in the outer tail feathers.
However, Martin Garner, who saw saw the images late this afternoon, suggests the smart money is on blythi – Siberian Lesser Whitethroat. If the bird is trapped, biometrics, DNA analysis and outertail feather pattern will all play a cumulative role in assigning the bird to race, while sound recordings and sonograms of the bird’s call (Sardinian Warbler-like rattle vs. standard ‘tac’ call of nominate Lesser Whitethroat) will also add weight. We’ll see.