Sure enough, he was not the culprit. Squirrels have been busy building a new nest in the oak tree.
Here is another look at their handiwork. I have never seen a squirrel nest under construction.
It looks to be about 2 feet around.
It is quite impressive and quite large.
My reading tells me that the interior measures only 6 or 8 inches in width and is lined with grass, moss and leaves.
Many spring evenings, as darkness approached, Better Half and I have watched a family of three squirrels flit from oak tree to oak tree to reach this home, located in another of The North Forty oak trees. We have enjoyed their acrobatics as they scamper about the branches. This nest has seen better days. All that remains are twigs and mulch.
Movin' on up!