This hole was occupied by a gray squirrel from late last summer until about three weeks ago. At that time its occupancy was contested by one, then a couple of white-breasted nuthatches. After about a week the squirrel abandoned the hole. The nuthatch pair have been cleaning, filling, emptying the contents ever since. One brings material to the nesting hole while the other removes more. Sometimes material is tossed from the hole; sometimes it's carried away to another tree; and sometimes one or both pack the material into crevices in the bark, seemingly decorating the entrance.

Note, added later: Apparently the contest between sciurid and bird isn't over. I don't know where the nuthatches are spending the night, but it's apparently not in this highly maintained nest hole. Just after sundown we spied the squirrel sneaking down from the tree top, nosing around the entrance, and then entering the hole. He's in for the night, it seems. I can't imagine they're all snuggled in together...? Nah....