Mike , I used to love Jackdaws...a very cool little bird, & smart , as you said.
I used to be an avid Bird Nester as a "Yout'" back in hedgerows of Somerset.
I remember Magpies as the real nest destroyers..they'd follow me sometimes, destroying the nests I found on occasion.Crows would do the same.
I used to delight in eating Magpie eggs to get revenge.
Rooks or Jackdaws didn't seem to bother.
Franc