I am afraid that I'm not up on Red squirrels and thus can't offer any constructive comment.
What I can offer is a warning to all on the Grey. These little pests will eventually win over lowland Forests regeneration. Fact. Unless serious thought, or as much attention as the reds receive positively, to their eradication, trees that include Oak, Beech and others that are common and a familiar sight on the landscape will simply not be there in the future.
Sorry to put such a negative slant on this thread!
Swyn.