I would agree that TTWP leave a definitive "sign" on the tree, but
, in my experience, it's not related to the pattern of holes. These birds,
and black-backed WP, pick the bark from large spruce,douglas fir and
lodgepole (in the area that I am observing) so that the tree looks like
some kids went thru with pocket knifes, but got discouraged before all the
bark was removed. It's particularly easy to find woodpecker tree in the
fire, because all of the burned bark is picked off exposing the orange
underneath. In the winter, there is usually also a pile of bark pickings
under prime trees.
Because the birds use a side-to-side motion of their head to get
to their prey, they can usually be easily distinguished at a distance from
hairy woodpeckers. Now is a great time to observe this behavior, becuase
the fledglings use quite an exagerated motion as they learn to forage.
Our reconnaisance on primary prey for the TTWP was flat headed
borers in year 2-3 post fire, and ambrosia beetles after year 3 (likely
due to the timing of arrival of these species.
Mary

Mary Poss, DVM, PhD
Department of Microbiology
Box 357242
University of Washington
Seattle, WA
mposs at u.washington.edu