I don't know if you happened to read the blog comment below from a woman in Harpswell, Maine (which is a coastal town a couple of hours south of Seal Harbor), but it's pretty interesting. We see red foxes quite often on Mount Desert Island but I have not seen a grey one. Nor have I ever seen a fox climb a tree. Have you ever had any good fox sightings?
Here's her comment:
"A grey fox has been a regular visitor at my neighbor's bird feeder here in Harpswell. We confirmed identification when 1) she snapped its picture and 2) it climbed a tree after a squirrel. Greys are the only tree-climbing fox. She now calls regularly with fox reports. Last week it (the vixen) crossed her garden with two young. Do you think the little fox would ever show herself to me? So far I have not caught sight of her but strongly suspect her presence at night when our Australian shepherd barks, then I find a scat near the house."