Actually, autumn began at 7:30 pm last night, but today is the first day of the new season. The color change of the leaves is very subtle, as it is just beginning, in this tree. If you look on the upper left side, you can notice the leaves getting lighter, as they lose the deep red color they had all summer long.
Yes, that is a four foot high (122 cm) deer fence around the tree trunk. Although the tree appears to be tall enough that the deer cannot decimate its foliage, I will not even attempt to remove the fence until spring. There is barely enough forage for the deer at this time of year, and I have seen hungry animals stand on their hind feet to eat whatever they can.