We have a wisteria vine growing on an open wide trellis above a small covered area adjacent to an old garage. It bloomed very well the past few years, but we noticed this spring (too late) that a squirrel that seems to spend a lot of time on the garage roof and the adjacent trellis has possibly eaten all the flower buds. I'm not sure why this never happened in previous years, but we did have a large Mme. Alfred Carriere rose bush that had somewhat entwined itself among the wisteria canes and I'm wondering if all the thorns on the rose canes were actually helping protect the wisteria. I cut back the rose last year because it was getting somewhat overgrown, not realizing the possible service it was doing. I'm wondering if there is any humane and ecological way to prevent the squirrel from doing the same thing next spring -- other than trying to get the rose bush to grow back again (and I'm not 100% sure that the rose is actually what prevented flower bud loss to squirrels.)
In my observations of the squirrels in the Garden, it is seemingly random as to what they chew on in any given year.
Try a humane trap and after catching relocate them to some unpopulated area. They are quite bold, some may say stupid, and will get inside lured even by the smell of urine of the previous inhabitant. A few peanuts or sunflower seeds will do the job, too.