Facts on the yellow-bellied sapsucker

To the uninitiated, the yellow-bellied sapsucker sounds like a mythical creature.

“Where is it in the field guide?” they ask. “Right next to the “bleary-eyed bedthrasher?”

“No,” I answer. “It’s a woodpecker.”

Four

There are actually four species of sapsuckers in North America, but only the yellow-belly is found here in the east. Williamson’s, red-breasted, and red-naped are all western species.

Sapsuckers are responsible for those evenly spaced holes you sometimes find on trees in late winter and early spring. When sap flows, it oozes from these “wells” and insects gather at the sweet liquid. Sapsuckers, warblers and even hummingbirds then visit the wells for banquets of sweet sap and protein-rich insects.

Sapsuckers also eat suet, and each winter I get calls about an unfamiliar bird at suet feeders. It’s about 8 inches long, black and white with bold white wing bars, white rump, and a bright red forehead. Some have red throats (males), and others have white throats (females).

Though most woodpeckers are primarily black and white, the prominent wing bars and red or white throat gives this one away. It’s the yellow-bellied sapsucker.

Though some first time observers might argue the point, yellow-bellied sapsuckers do indeed have yellow bellies. But the yellow is as pale as the red on a red-bellied woodpecker’s belly.

Sapsuckers usually head south for the winter, so they’re uncommon in January.

Spring

Though seldom heard during the winter, sapsuckers become easy to detect by ear in the spring. Their staccato drumming pattern is diagnostic. It sounds more like a Morse code signal than a smooth drum beat.

Because sapsuckers, like flickers, are migratory woodpeckers, they’re uncommon feeder birds. In 20 years I’ve seen only a handful in my backyard during the winter months. But by April, sapsuckers return to northern deciduous and evergreen forests where they nest.

The male selects the nest tree, often the very same tree he used the year before. Both sexes then excavate the cavity, but the male does most of the work. The female conserves her energy for egg production.

More often than not, sapsuckers select a live aspen or poplar infected with a heart rot fungus. The fungus softens the inner heartwood and makes excavating the cavity less difficult. The hard outer wood is not affected by the fungus and protects the nest from predators such as raccoons that might try to tear open a rotting cavity.

After as long as 19 days, the cavity is complete. The female then lays one white egg each day for five or six days. Both parents incubate the eggs for about 12 days. The male handles the night shift. During the day the male brings food to the nest for the female. After hatching, the nestlings remain in the nest for another 24 to 28 days. During that time the parents feed their young sap and a variety of insects. Sap accounts for as much as 20 percent of their diet.

First lesson

After young sapsuckers leave the nest, their primary job is to master the art of sapsucking. They stay with their parents and use the feeding stations the parents have already established. These stations are easy to recognize. Sapsuckers drill vertical and horizontal rows of sap wells along the trunks of a wide variety of trees. Sap wells have been observed on more than 275 species of both deciduous and coniferous trees.

Each well is about 1/4-inch in diameter and oozes a steady stream of sugary sap. Sapsuckers lap the sap up with their bristle-tipped tongues. The sap also attracts insects, so sapsuckers can meet most of their nutritional needs at sap wells. They aggressively defend their sap trees from hummingbirds, warblers, squirrels, and any other critters that crave the sweet stuff.

Homeowners and orchardists sometimes curse sapsuckers for the harm they do to trees, but the damage is usually cosmetic. Healthy trees heal quickly; sapsucker populations are rarely high enough to cause major damage.

By summer’s end juvenile sapsuckers are independent, and most head south with the adults. If you see any stragglers in your backyard this winter, offer suet or, on mild days, hummingbird nectar (one part sugar, four parts water).