Hello

My first post to the world of tree people and tree artists all and I would like your advice please.

I trimmed the sycamore in the photo about June last year just before the drought and it reacted very poorly. Specifically I removed any  dead branches of which there weren't that many of any size. There was a hefty branch that had broken off and I merely removed it without a live cut. I don't think I took off more than about 10-15% in volume. It seemed to react poorly - leaves started shedding except for one smallish area that retained leaves.

The photo is taken this year - there is the start of some leaf growth at the top left in that small area that did well. I am curious because all the sycamores around - I am in London, seem to be in leaf. The squirrels I believe caused the damage which led to the  previous branch death. Looking at the tree now I can see maybe half-a-dozen branches stripped bare by the squirrels.

So, what's the prognosis?

Is the tree just slow to come into leaf?

Could last year's trim have been the death knoll?

Can trees have some really bad years of semi-dormancy before springing back?

Can squirrel activity be as bad as to kill a tree?

Many thanks

Dom