The Beat of the Yellow-bellied Sapsucker’s Drum
The changing of our ash tree’s leaves marked the beginning of fall at Madison Square Park. During this time, birds migrating from the North to warmer southern regions have come and gone just like most of the leaves in the park. The symphony of bird calls and songs have slowly softened, and the frenzy of migratory activity has nearly come to a stand still as the winter cold begins to cover our cozy urban oasis. In this stillness, a strange percussive drumming pattern will attempt to fill the void. The rolling taps coming from the trees are the distinctive sounds of the Yellow-bellied Sapsuckers.
Yellow-bellied sapsuckers are normally a quiet species during fall and winter. Their vocalizations are mostly reserved for the spring mating season, but in the fall, food and space become vital resources for many species in the Park. The drum pattern produced by the yellow-bellied sapsucker is not only a by-product of their forages, but it’s also a method of claiming territory and attracting mates. When protecting or claiming a territory, sapsuckers will find the loudest material available and drum as hard as they can in a series of hard, short rapid taps, followed by a few slower, louder, spaced taps at the end. In urban areas, some resourceful sapsuckers will even go as far as drumming on metal signs and surfaces to produce a more thunderous warning.
In most cases, however, the drumming patterns are a burst of softer taps. Faint drumming can indicate that a sapsucker is nearby probing trees for sap or working on an active “saw well.” As their name suggests, yellow-bellied sapsuckers prefer tree sap as a mainstay in their diets along with arthropods, fruits, and nuts.
During their forage, Sapsuckers will zip around trees, like the sweetgum, magnolia, hackberry, oak, and elm in the Park, probing bark in the search for sap. They do this by using their specially designed claws to grip onto the surface of the tree and blasting their bill into the wood, carving out a round hole just deep enough to reach any sap that could be sitting beneath the surface. Should a sapsucker strike gold, they continue to dig creating a more rectangular notch. These notches are a sapsucker’s sap well. The targeted tree reacts by oozing sap to cover these intrusions. The sapsucker will then visit the well and use their tongues to lap up the oozing sap before it hardens. If a territory is carefully protected, a sapsucker will often revisit and tend to their sap wells.
While unattended, the sap wells will also serve its larger ecosystem by feeding several other insects and birds like butterflies and hummingbirds. Foster and Tate, 1966 found that at least 35 different kinds of birds are associated with sapsucker wells either for the sap or the insects attracted to the sap or both. Every now and then, the sapsucker’s commensalistic behavior will be rewarded with the delightful discovery of a delicious sap covered bug.
Sapsuckers are yet another species showcasing the wonders of evolution and adaptation. Their special design is what allows them to survive and benefits the local ecosystem.
Next time you are in the Park and there is a stillness in the air, keep an ear open for the strikes of a yellow-bellied sapsucker by Elm, Sol Lewitt, and Farragut lawns. To learn more about the birds and other flora and fauna throughout Madison Square Park, visit eBird and iNaturalist, or read more about our ongoing initiative to support our local wildlife.