Warblers and Sapsuckers

The Yellow-rumped Warbler will take sustenance, wherever it’s offered. (Courtesy: Lang Elliott)

Warblers are passing through now, often in mixed flocks, so the other day I took a closer look at bird activity in a willow tree. The most common warbler in New Hampshire is the yellow-rumped warbler, named for its neon-yellow rump patch, and the five birds active in the willow were indeed yellow-rumps. But they were fluttering near the tree trunk – that was a bit odd for a bird that usually hunts insects out on the leaves.

I stepped closer and found them competing at two small tree wounds that were glistening with sap. Evidently, a yellow-bellied sapsucker was passing through as well, and paused at the willow to refuel. In addition to a unique name and a unique diet that includes tree sap, This woodpecker also has a unique drumming cadence.

My watch the other day was rewarded by the return of the sapsucker with one warbler companion. The warbler drank from one glistening sap well while the woodpecker worked at another. Through my binoculars I could see rows of small holes that looked like a BB gun marksman had shot orderly lines around the tree trunk, neat and tidy. In spring, when sap flows upward, rousing trees from their winter dormancy, sapsuckers drill these small, tidy rows. On the other hand, in summer they have to excavate a larger, rectangular sap well. Take a look at an old pear or apple tree, and chances are good that you'll see the BB gun rows. These may date back a couple decades to a time when yellow-bellied sapsuckers were more common.

Now, hummingbirds are known to drink at sapsucker wells in the spring, but warblers in fall? That was new to me!