Blackcap......?
Whilst relaxing with a coffee in the conservatory I I had seen a few Long tail tits fly into the top of the fir tree so grabbed my camera & lens and hung out of the bedroom window. Unfortunately Shelby followed me and immediately starting barking which frightened the birds away (one of her favourite tricks). However right at the end of the garden I noticed a little movement in the elderberry tree full zoom to see what it was - a new one to me - managed one quick shot and it was gone. But at least I have seen one. Having searched Google, I believe it to be a Blackcap.
@randystreat I think your chickadees are similar to our Great tits and Coal tits. This is what I found out about the Blackcap - https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/blackcap The blackcap is a distinctive greyish warbler, the male has a black cap, and the female a chestnut one. Its delightful fluting song has earned it the name 'northern nightingale'. Although primarily a summer visitor birds from Germany and north-east Europe are increasingly spending the winter in the UK.