In my local nature reserves there are a couple of sequoia (I think - they're huge conifers, about 6 feet diameter). Both of them looked like they'd been wire brushed - initially thought it was yobs (who have tried to set them alight at some point) but it extends a long way up the tree (at least 20') and seems an odd choice of vandalism.
Seems a huge area of damage if it's squirrels
Seems a huge area of damage if it's squirrels