Earlier this season, there was a pair of chickadees excavating a perfectly round hole in our flowering Plum tree (which is decaying). We are keeping this tree because the birds love it. I believe the mowers may have scared off the chickadee pair with the equipment. Then a couple of weeks ago, a pair of Downies started continuing the excavation- throwing out lots of wood chips and deepening the hole downwards. The downy's entire body now fits into the excavated hole. Would downy woodpeckers start nesting this late in the season? I know there are plenty of insects etc in this tree, but both the downy and the chickadees have been throwing out wood chips, possibly making a nest.... Bev Propen, Orange