While noticeable by its red crown and forehead and black and white striping and spotting, the Yellow-bellied Sapsucker, a medium-sized woodpecker, is distinguishable by the yellowish wash of color across its belly, back and top of chest and from the holes it bores in trees. (Photo by James Solomon, USDA Forest Service, Bugwood.org)
While not a regular winter resident, the evidence of its presence is noticed more often during this time of year and early spring before leaves are present and sap is leaking from the holes. Suddenly noticing holes in your tree may be disconcerting and result in a small amount of panic that your tree is sick or may die. While less than attractive, the holes created by Yellow-bellied Sapsucker are usually not a major problem. Healthy trees quickly grow over these small injuries.
The key to identifying the sapsucker holes is the odd way the bird makes them. They create neatly spaced holes in rows or blocks of rows. Holes created by insects will be random and usually much fewer. Only a few insects make holes as large as a sapsucker, and they will not be in rows. While creating holes the yellow-bellied sapsucker eats the inner bark and drinks sap. Later, they defend these holes from other animals, continue drinking sap and eat insects attracted to it.
Commentary is by Jon Skinner, urban forester for the Missouri Dept. of Conservation