I believe that future observations will reveal similar use of hemlock over a much larger area. If you wish to make a quick check for evidence of sapsuckers, look at the hemlocks. If nesting does not occur in a region, migrants probably made the holes. Apple a key species . Current evidence suggests that trees of the apple family may form an important link in the life history of sapsuckers.
Migrants add to damage .
Migrating sapsuckers add to the damage caused by local nesting birds. Both spring and fall migrants normally used the same trees damaged earlier the same year, or in preceding years. Migrants pass through our local sapsucker territories in several waves. Individual migrants stay and feed for several hours to a week or longer. Later migrants may use the same trees.