Sapsucker’s work feeds forest

Its somewhat laughable name makes the yellow-bellied sapsucker sound like a character straight out of a cartoon.

But I’ve gained a profound new respect for this sparrow-size bird: Its ability to make sap flow from living trees during winter makes it unique; the sap it brings forth provides nourishment for numerous creatures as well as the sapsucker.

My newfound interest stems in large part from a yellow-bellied that has been frequenting the woods behind my home on the outskirts of Decatur this winter. I often see it as it tends it “sap wells” or drills for new ones in the trees, mostly in a big tulip poplar but also in some oaks, pines and other trees.

A member of the woodpecker family, the sapsucker is one of Georgia’s most common winter birds, usually arriving in early October and leaving in April for its summer nesting grounds up north —- our only migratory woodpecker. It’s not unusual, then, to have sapsuckers in our neighborhood this time of year, but this one seems to be more visible than usual —- perhaps because it hasn’t noticed me observing it through binoculars from my office window.

The yellow-bellied sapsucker is elusive, often remaining undetected. About the only sound it makes this time of year is a soft, catlike mewing that sounds like “meeur.” If it senses an intruder, it usually stays on the opposite side of the tree, unseen.

You can readily tell, though, if a yellow-bellied sapsucker has visited your yard or neighborhood by its calling cards —- a series of small, round, fairly evenly drilled holes in the bark of living trees. The shallow holes, or “sap wells,” are most visible this time of year, when most hardwoods are bare of leaves. The holes allow the tree’s sap to flow. The sapsucker then licks up the juice, its main source of nutrients.

When searching for a good sap well, the bird may spend hours laboriously drilling the series of tiny holes in parallel rows, eight to 20 feet above the ground. Once it finds a good well, the sapsucker may return time and again, year after year, to keep it flowing. Sweetgum, oaks, maples, hickories, pecan, tulip poplar —- in fact, more than 400 species of trees and shrubs —- all appear to be candidates for sap wells. It is not known, however, why the bird might prefer one tree over another.

The sapsucker licks the sap with its brush-like tongue, tilting its head back as if swigging beer. Because it licks the juice instead of sucking it, as its name implies, some say the sapsucker is wrongly named. “Saplicker” would be more appropriate, they say.

Actually, getting sap to flow steadily in sufficient quantities from a tree is a difficult task, and it makes the sapsucker a unique bird. Researchers have tried to copy the sapsucker’s drilling techniques, but failed. It is thought that sapsucker saliva may contain a substance that acts as an anticoagulant, preventing sap from clogging up and sealing over the holes the bird drills.

The sapsucker’s feeding habit also is a boon to other species, providing them a rich carbohydrate food source during winter. Tree sap is similar to flower nectar in the amount of nutrients and sugar it contains, and thus is a very suitable nectar substitute for insects, hummingbirds and other creatures. It’s possible that the hummingbirds being seen in Georgia in increasing numbers during winter depend, in part, on sapsucker wells. Some songbirds —- and sapsuckers themselves —- also may feed on the insects attracted to the sap-oozing holes.

Other species such as “kinglets, warblers, Baltimore orioles and cedar waxwings feed from the wells … especially in winter when insects, fruit and nectar are not as readily available,” writes Marietta birder Giff Beaton in his book “Birds of Georgia.”

Not everyone, though, is enamored with sapsuckers. Some homeowners believe the bird’s holes severely weaken trees. Foresters say that sapsucker holes lower the value of trees for timber.

For the most part, however, sapsuckers cause minimal tree damage, and I, for one, am always glad to see them.

One other note: The sapsuckers we see in Georgia during winter most probably are males. The females fly as far south as Central America for the winter. Distinguishing features: Male has a “red chin;” female, a “white chin.”

In the sky

The moon is in first quarter today —- in the south at sunset and setting around midnight, said David Dundee, astronomer at the Tellus Northwest Georgia Science Museum.

Mercury is very low in the west just after sunset. Venus shines brightly in the west just after sunset and sets in the west about three hours later. Jupiter sets in the west just after dark. Saturn rises out of the east about 10 p.m. Today, the Earth reaches perihelion, the closest the planet will be to the sun in 2009 —- about 91.9 million miles away.

seabrk@comcast.net