Injured bird - fell down chimney

A big black bird has fallen down my chimney (for the third year running!)  Think it may be a jackdaw.  We blocked the chimney with some wood near the bottom this year, luckily, and have just returned from a couple of days away to hear the noise of a bird stuck in there.  Have got it out, but it seems to have injured it's wing and is bleeding.

I have put it in a bucket in the garden (on the table) with some leaves and straw and left some water and bird seed in the bucket.

Hopefully it will be OK and if it's still alive in the morning - any advice as to what to do next?

Thanks so much.