But there is no doubt this wasn't a 'classic' bird, at least in my eyes. When it first arrived it looked good (see above) but you would have walked straight past it if you were only 'listening' for Siberian Chiffchaffs. Take a listen here:
The calls represented here were typical of what it was giving constantly. Interstingly since first picking it up in early December I have hardly heard it call in all the visits I have made over to look at it. However it called several times yesterday and I managed to get two snatches on my Remembird:
None of these calls are the true tristis 'peep'. They are virtually all a clear rising 'wheep' just like collybita. The two calls recorded yesterday are actually much closer to a true tristis call but still aren't really flat, as you can see in the sonogram above. So where does that leave us?
Well, it looks like a tristis, and it sings like a tristis, but doesn't really call like a tristis. Is it a tristis? I think so. This bird is a prime candidate for having some DNA work done so we'd know once and for all, that tristis can call just like collybita.