Look who's back!

I haven't seen Squirrel Nutkin for many months but there he was this morning on the top of the bird feeders.
My bird feeders are supposed to be squirrel proof but during his absence Nutkin has been working on a strategy for getting at the seeds.

If anything heavier than a small garden bird visits the perch is depressed and the shutter closes so no seeds are on offer.
Nutkin has worked out that if he doesn't put any significant weight on the perch the wee shutter stays open and some seeds can be enjoyed.