I was rambling about this bird a few weeks back, gave me quite a surprises when "she" started to sing

Well, I did notice one tiny side-flank feather, though I can't really tell the colour.
Can't wait for him to colour up! Will post more pictures when he does so

I think his colour is getting more lighter, or more brown...or something. Maybe he is an isabel after all. One way or another, I'm starting to think the parents stole his egg from some other bird

rather puffed up on those pictures, taken a few days ago

