In past columns, I’ve referenced a maple in my front yard as being the woodpecker tree. This large tree is essentially sound, with some developing black fungus on the bark surfaces that attracts gangs of brown creepers, titmice, two species of nuthatches and four species of woodpeckers. Recently, an active pair of yellow-bellied sapsuckers has proven the most interesting and entertaining. Sapsuckers are the most migratory of the woodpecker clan, with returning males appearing in early spring, followed by females several weeks later. Except for during nesting season, they are often solitary individuals that remain quiet and motionless. Their mottled plumages blend closely with bark patterns, adding to their concealment.

By early April, I begin hearing the male sapsucker’s shrill, squealing calls and distinctive drumming rhythms that announce his presence. Typical drumming cadences begin rapidly but, near the end of the sequence, slow to dragged-out, countable taps. Male sapsuckers seek the most resonant-sounding posts, such as telephone poles, dead hollow branches, and even metal street signs, to amplify the effect.

As their name would imply, sapsuckers use their unique brush-like tongues to ingest tree sap — a process involving capillary action. Their heavy liquid intake leads to some predictable physical outcomes: sapsuckers tend to void away quantities of liquid waste about every 10 to 15 minutes. As versatile insect catchers as well, they glean insects from bark or catch prey on the wing. The nestlings rely on a diverse diet of insects to support rapid growth. Fledgling sapsuckers can take sap, but they don’t drill independently until around August.

Male and female birds share attributes of feather details. Intricately marked head patterns, crimson red caps, barred backs and brownish mottled underparts are the key features. Throat color varies by sex – red for males; white for females. A bold white line across the wing is a diagnostic field mark. And what about that namesake yellow color on the belly area? That particular hue is quite variable within individuals and age groups.

Rarely using a previous nesting cavity, sapsuckers carve out a new nest hole each year. Those vacant holes provide snug quarters for flying squirrels, however. Although both mates share the excavation duties, much of the work is completed by the male. Theory suggests that the female must conserve her physical capacity for the rigors of egg-laying. There are instances where the finished nest entrance is a bit tight, creating a wriggling situation for the egg-bearing female. And cavities that are too shallow are subject to raccoon reach-ins.

My neighborhood pair forages daily at the maple, drilling rows of horizontal holes that are well spaced apart. Drilling of new wells may occur in the earlier parts of the day, allowing the pair to reap the leaky benefits in subsequent sunlight conditions. The birds are orderly and methodical in their drilling and tending of the sap wells. Wells are visited in an efficient, sequential manner, allotting time for the holes to refill between visits. Other species, including chickadees, nuthatches, red-bellied woodpeckers and hummingbirds, take advantage of the sweet, dripping solution.

A momentary calamity struck last week when an intruding male sapsucker landed on the pair’s tree. Raspy, threatening vocalizations, raised head crests and bodily interventions worthy of the pro wrestling circuit soon followed. Amidst a spray of splashing sap, the home pair stalked the offender around and around the main trunk, until he exited. In coming months, I can hope to see their offspring at the woodpecker tree.