Is This a Juvenile Blackbird?

This one has been a real puzzle for me, partly due to its very bedraggled state and how late so many of our birds are breeding this year. You can see many pins in the throat and nexk area as well as balding on the back of the head. The breast does not look speckled to me, although the colouring over all is confusing with green in the down, rich brown on the wings, almost a fawn nearer the chest. I looked at wrens, creepers, runners, pipits, nightjars, larks... I'm utterly lost.

Further details which may help:

> the bird had a waterdrop call which I can only write as "wuk wuk"

> it was feeding on those berries, which I believe are likely blackthorn/sloe

> there were blackbirds nearby and also feeding there

> it was in a densely shrubbed/treed area on a common/heathland nowhere near water

I can rip out and post a copy of the call if you folks need it but hopefuily someone here can just be more informed than I am and say "It's this bird." That would be great!