ID of part of a bird

I found this bird by the side of the house and wondered what it was. Unfortunately the head has been taken by an animal.

I can't guess if it was an adult or a fledgling. The nearest nest we know of is a a blue tit nest in the box about 20 feet away, but this one doesn't look like a blue tit.

b1 by Dave Marley, on Flickr

b2 by Dave Marley, on Flickr

It is about 8 - 10cm

Can anyone identify it or make a guess?

Thanks

Dave