Have you ever noticed a trunk of a tree with several horizontal rows of rather small and shallow oval shaped holes in the bark? I suspect that many among us have, but probably do not know the cause. It’s the work of yellow-bellied sapsuckers, a type of woodpecker.
Yellow-bellied sapsuckers are about 8-9 inches long. That is larger than a downy woodpecker, but closer to that of a hairy woodpecker. As their name implies, they have a noticeably yellow tinged belly. Males have a bright red crown and throat, black mottled back, white wing patch, and a black and white stripe from near the beak and eye that curves down the neck. Like many other birds, the females and juveniles are less colorful.
The term sapsucker is no misnomer. They do suck sap. The telltale sign of sapsuckers is the horizontal lines of small oval holes in bark. Unlike most woodpeckers that hammer away on trees to get at insects, sapsuckers excavate small shallow holes in the bark to get at the sap which they lick up as it oozes from the holes. Because the tree’s phloem or sugar conducting tissue tends to clog up above the holes, the sapsuckers will often excavate other horizontal lines of holes above the preexisting holes to get even more sap. Sugar maple, birch, Scotch pine, and aspen with heart rot are known to be preferred trees for sapsuckers. They will revisit the flowing sap periodically. And that flowing sap attracts other birds including other woodpeckers, hummingbirds, warblers, and nuthatches. Porcupines, squirrels, and bats are also known to exploit the running sap.
The breeding range for yellow-bellied sapsuckers is roughly the coniferous forest of the northern U.S. and Canada. And they are migratory, spending their winters in the southeast United States and Central America. As such, they are summer residents in our state, mainly north and east of the Missouri River. They are quite common in Turtle Mountain, Pembina Hills, Devils Lake area, and timbered bottomlands of the Sheyenne and Red River and their tributaries.
If you are not familiar with the sapsucker’s excavations, you may have heard them drumming. Yellow-bellied sapsuckers are known for their fondness for tapping out their territorial calls on metal surfaces. Eave troughs, flashing on roofs as well as ridge roll are big hits with sapsuckers. We used to see and hear one frequently hammering away on an aluminum stepladder in our back yard. The hammering has stopped for now. Maybe he found the love of his life elsewhere.