We have the same problem but it doesn't seem to bother the birds - they just wait until he's gone and then resume feeding
so I have no doubt that your birds will be back. This cheeky squirrel can also climb up the bird table and raid that as well and some of my neighbours have also seen him doing the same thing. Think he must be doing the rounds. Someone on the forum suggested putting chilli powder on the bird food to deter them but it doesn't really bother me. He's not here all the time .
The biggest problem we have at the moment is a Jay who is eating everything in sight.