Out My Backdoor: Yellow-bellied Sapsuckers

close up of a Yellow-bellied sapsucker on a tree.
Yellow-bellied sapsucker (Terry W. Johnson)

By Terry W. Johnson

Even if you have never seen a yellow-bellied sapsucker, chances are you are familiar with the bird’s name.  Growing up, the guys I hung out with would call you a yellow-bellied sapsucker if you refused to do something they thought proved you were a coward. Years later, I learned there actually is a bird named the yellow-bellied sapsucker.

Since the bird doesn’t act cowardly, I have no idea how cowardice how became synonymous with this unusual woodpecker. Actually, the yellow-bellied sapsucker is so named because it eats lots of sugary sap it obtains by drilling small holes in more than 1,000 trees and  woody plants. This sap is not actually sucked into the bird’s mouth. Actually, it sops up the sap with a special brush-like structure at the end of its bill.

The yellow-bellied sapsucker is the only woodpecker found east of the Mississippi River that is truly migratory. It nests primarily in the upper Midwest and northeastern U.S. The birds winter in the Southeast, West Indies and Central America. Fascinatingly, since three times as many female yellow-belled sapsuckers winter farther south than males, the vast majority of the sapsuckers we see throughout Georgia in winter are males (males have red throats).

I typically hear far more yellow-bellied sapsuckers than I ever see. While the bird has a number of calls, the one I am most familiar with sounds much like mewing of a cat. If I hear such a call on an icy winter morning I know it’s a sign that a yellow-bellied sapsucker is probably nearby.
Sapsuckers often travel in small flocks of Carolina chickadees, brown-headed nuthatches, brown creepers, kinglets and titmice. Thus, the bird’s catlike call tells me to stop what I am doing and begin looking for a band of hungry birds.

The only other bird that sound might be is the gray catbird. While the gray catbird is a summer resident, it is rarely seen in middle Georgia in winter. However if you live in south Georgia, there is a greater chance you just might be hearing a catbird.

While the feeding habits of the yellow-bellied sapsucker during the breeding season are well known, biologists know far less about the bird’s feeding habits while wintering here in the Southeast. Although sap is recognized as the major source of food for the bird during winter, we have little understanding of how fruits and berries of plants such as poison ivy, black gum, Virginia creeper, hackberry, red cedar, and dogwood supplement the sapsucker’s diet.

In addition, there is little information regarding the role that arthropods such as ants, spiders and their eggs play in the sapsucker’s winter diet. (Interestingly, sapsuckers will actually dip ants and other insects in the tree sap that collects in their sap wells before eating them.)

Since yellow-bellied sapsuckers are also known to hoard seeds during winter, those may also be an important source of food.

Unfortunately, while we do not see yellow-bellied sapsuckers as often as we would like, signs that they are here are all about. Of course, I’m referring to holes they leave in tree trunks when looking for sap. This woodpecker is well known for chiseling wells in horizontal rows and columns that completely encircle a tree trunk. Each hole represents a spot where a sapsucker drilled for sap. When they locate a spot where sap oozes out of their excavations, they will dig additional holes nearby. When a sap well runs dry, the bird drills another directly above it.

Each well is shaped like an inverted cone, a configuration that helps keep the sap from leaking out.

If you closely examine the holes, you also will find that their shape varies from round, or oval, to rectangular. Round holes extend deeper into a tree than rectangular holes. The reason for this is that rectangular holes extend only into the inner bark, or phloem, of the tree. For the woodpecker to maintain the flow in the band of holes around a tree, they must constantly enlarge the holes. In doing so, the holes eventually take on a rectangular shape. The sap-filled fibers in the tree’s inner bark are called bask. Sapsuckers will actually consume the bask and cambium along the edges of the holes.

To give you an idea how important sap wells are to these birds, one sapsucker returned to feed at its sap wells more than 500 times an hour for eight and a half hours.
Sapsucker wells are also a source of food for critters such as insects, chipmunks, squirrels, ruby-crowned kinglets, Carolina chickadees, wintering hummingbirds, other woodpeckers,  moths, butterflies and nuthatches.

I should note that the only time I have seen a Rivoli’s hummingbird (formerly named the magnificent hummingbird) was in Winder one winter years ago. During the entire time I was visiting the yard where the Rivoli’s was feeding, this large hummingbird never visited a feeder. Instead, it fed solely at sapsucker wells.

Fortunately, for those of us who feed backyard birds, yellow-bellied sapsuckers will also visit our bird feeding areas. The foods they are most attracted to are bird puddings, suet, jelly, fruit and even pastries. They have also been known to dine at hummingbird feeders. A backyard bird enthusiast in south Georgia revealed to me that sapsuckers frequent the holes he drills in scrub oak logs and fills with a mixture of peanut butter and oatmeal.

There is a smattering of reports of yellow-bellied sapsuckers feeding on sunflower seeds.  A homeowner in Virginia told me they do so at her feeders. In addition, retired DNR wildlife biologist John Jensen reports that a yellow-bellied sapsucker routinely eats sunflower seeds at his feeders in middle Georgia.

Personally, I have had the best luck attracting yellow-bellied sapsuckers when I place a container stocked with grape jelly directly against the trunk of a tree.

One more note you might find interesting: When ruby-throated hummingbirds beginning migrating northward each spring, one of the foods they depend on to fuel their journey is the sugary sap they glean from sapsucker wells.

Like so many wild critters, once you catch a glimpse of the private lives of yellow-bellied sapsuckers, it is impossible not to have a greater appreciation of them. I hope you agree that the wild residents living just outside our backdoors are truly fascinating creatures.

Terry W. Johnson is a retired Nongame program manager with the Wildlife Resources Division and executive director of The Environmental Resources Network, or TERN, friends group of the division’s Nongame Conservation Section. (Permission is required to reprint this column.) Learn more about TERN, see previous “Out My Backdoor” columns, read Terry’s Backyard Wildlife Connection blog and check out his latest book, A Journey of Discovery: Monroe County Outdoors.”