Siberian lesser whitethroat, Preston

For the past few days there's been a probable Siberian lesser whitethroat Sylvia curruca blythi at Ribbleton, Preston. 'Probable' because there are other eastern races of lesser whitethroat which can't be ruled out without resorting to DNA samples which as far as I know have not yet been obtained.

As I understand it, the current thinking is that blythi is more closely related to these eastern races than it is to the western races which include the nominate UK race curruca. This leaves potential for a split into two species, western lesser whitethroat which would include curruca, and Central Asian lesser whitethroat which would  include blythi and the other eastern races. If this eventually happens, then in the field it would "only" be necessary to identify it as an eastern bird in order to get it to species level, although DNA would still be required to determine exactly which race of Central Asian lesser whitethroat. 

Fortunately there are features of this bird which are strongly indicative of it being one of the eastern races, even if we can't say for sure exactly which one, and some of these features can perhaps be seen in this photo. For example the sandy brown of the mantle which continues onto the nape, the buffish underparts contrasting with the white throat, the pale panel in the secondaries and the faint supercilium. Also, perhaps there is a longish tail and short primary projection, whilst not really apparent in the photograph are the pure white outer tail feathers. The bird called a couple of times with a 'tack' which apparently rules out at least one of the other eastern races (halimodendri). Blythi is thought to be the most frequent of the eastern races to visit the UK and when DNA has been obtained from other birds, it usually turns out to be this race.

Between yesterday and today I spent about 5 hours on site in order to get two views which lasted about one minute in total. Still, well worth it in my opinion. I'm pleased with the above photo.

My third Siberian lesser whitethroat, following birds at Retford and Spurn.

The bird has been seen all along this avenue on both sides and often goes onto feeders in the adjacent gardens which are not viewable from outside.