In reply to Phil1919:
I usually hear G spotted woodpeckers first, they make a distinctive metallic "chink" sound. Once you recognise it, you may find they're around more than you realise.
Kingfishers - you'd think that the orange front would be highly visible - not so when there's a dull colour or an earth bank behind. Even the bright blue gets camouflaged more than you'd think by dappled sunlight and reflections off water. I haven't seen one in the UK for yonks, but then I've probably not been in the right places.
Once it's late spring, if Covid is far enough on the decrease, then I'm going to start stalking Mick on his morning walks 😎