Desert / Central Asian Lesser Whitethroat

On the morning of November 8^th at Donna Nook Lincs there had clearly been a good arrival of thrushes, mainly Blackbirds, but also up to 30 Robins and a few other birds; one of the first birds we came across was a  small sandy coloured warbler that I immediately thought looked good for an eastern, recently central asian, Lesser Whitethroat. The bird landed in a small hawthorn but then quickly went down into the marram where it was catching caterpillars; it could be easily overlooked and we lost it for an hour or so but it could generally be found in the grass or low in the scattered elders and hawthorns where it seemed to go when disturbed. It was strikingly pale sandy on the upperparts and with a contrasting whitish throat and upper breast then a peachy – buff lower breast, belly and flanks. The bill was short and the head pattern weakly marked compared to nominate Lesser Whitethroat with a white crescent below the eye being more obvious than the weak crescent above; most of the features of the bird are shown in the attached photos with a poor OOF flight shot that shows the extent of white in the outer tail feathers. Its jizz was often reminiscent of Desert Warbler tipping forward when feeding and even burrowing into clumps of marram when searching for food; 

The most distinctive feature of the bird apart from its looks was its call a mid toned dry rattles series of notes described as trrrrrrrrrt total dissimilar to the call of nominate birds.
I have attempted to upload two poor quality recordings of the call on YouTube link below   http://www.youtube.com/watch?v=a0js9PwYsWo
http://www.youtube.com/watch?v=E3NMx_GruXQ

Compare the calls with this recording of minula
http://www.xeno-canto.org/species/Sylvia-minula

It looks very similar to the bird in Aberdeen British Birds 98 (11) Eastern Lesser Whitethroat in Aberdeen and the same bird in Birding World 17 (12) 502 – 504 Apparent Desert Lesser Whitethroat in Aberdeen. But as all authorities seem to say making sub-specific identification between minula and halimodendri in a vagrant context is not practicable; the plumage and calls however, make these birds a different bird to our summer breeding Lesser Whites.