Well glen you have answered your own question really: trees cut down which provided food and cover for the birds and a cat in your garden. I would try and discourage the cat as you don't want your feathered visitors to become food for the cat.
Lots of birds will still be feeding in the countryside but will soon be back as it gets colder. Please continue feeding all the year round as advised by the RSPB, link attached.
http://www.rspb.org.u...eding/whentofeed.aspx
Good luck and it's great that you are looking after our birds:-)