[Tursiops2]

Originally Posted by Catrin

Having heard it singing from a neighbour's TV antenna this afternoon I'm quite prepared to believe that it is some kind of canary - a very complex song with lots of variation and trills - however, the back does seem to suggest that it is a cross with something else.

I didn't know that canaries could cross with finches, however, a quick google has told me that they are commonly crossed in Europe with goldfinches, siskins and greenfinches - I now understand why you are referring to it as a 'mule'.

Thanks for everyone's suggestions. Sorry, but we haven't been able to take any more photos of it this afternoon.

OK, that does seem to rule out any sort of sparrow then