Tales from the Help Desk, Strange Markings

Q. What are the strange marks on my holly tree? 

A. Those strange, rectangular shaped bare spots in the bark were made by sapsuckers, a type
of woodpecker. While these birds eat insects, fruits, and nuts, they also enjoy tree sap. Here in
eastern North America, the most common and destructive of these birds is the American
yellow-bellied sapsucker, Sphyrapicus varius. These are migratory birds that feed in Virginia
when the sap begins to run in March, and then again in November.

Sapsuckers usually make deep, round holes organized in orderly rows. But sometimes they
create patterns of shallow rectangles as seen in the photo. The sapsucker removes the bark
and then comes back the next day to lick the sap that has oozed into that hole. Sapsuckers tend
to choose a favorite tree and then return to that tree frequently.

Sapsuckers are protected by state and federal law under the Migratory Bird Treaty Act.
Therefore, homeowners can not harm these birds, and are limited to methods that scare the
birds off or limit their access to the tree. To limit sapsucker damage, wrap the damaged areas
of a tree with a protective material, such as burlap, during their feeding periods. Remove the
material at other times, to allow for the tree to grow and expand. Hanging shiny objects or
plastic owls in the tree may also help.