3 unidentifyable birds

I live in the Derwent valley in the North East of England and i have been filming wild birds for a couple of months now. I went on an early morning walk to a new wetland spot,  and aswell as others i have some footage of 3 that i cannot identify and the books i have looked in cannot either. I have posted the video with the 3 on youtube and i cannot use the uploader on the site, this is the link for the video. It is only around a minute long and the videos are clear http://www.youtube.com/watch?v=kj2er5Vb4s0 The first is about the size of a robin and dark brown. The second bird is what has me the most intruiged and i have been told by one person it could me an immature cuckoo, about 15cm long and a greyish colour and the last one is a robin lookalike with a lush white belly but no red breast. Thank you i hope somebody can shed some light on these beauties.