Fig. 4. Examples of the trees within our 500-ha study area with tightly adhering bark that has been scaled. Sweet gum (A, B, F) and spruce pine (D, E) commonly showed feeding sign. (C) A chisel on a small hardwood on which the bill of a foraging bird caught a thin section of the underlying sapwood and curled it. The arrows indicate the bore holes of insects revealed when bark was scaled away by a woodpecker.