Pileated woodpeckers spent the early part of the winter boring out some of the Aspen (Poplar or Popple) trees behind the house. I’m not sure what influences their choice of trees. The trees they chose don’t look much different than their unscathed neighbors, but obviously they have very specialized knowledge about what they are doing. From January though a few weeks ago these holes were covered in snow, so they couldn’t have provided the birds with winter roosts. The choice of such spots suggests that these were exploratory feeding holes as the woodpeckers searched for bugs.
One curious observation is that all the holes were all located low on the north sides of the trees. I’m not sure if the northward placement was intentional or if things just worked out that way.