As the autumn bird migration draws to a close for 2024, we’re delighted to be finding five of our favorite visitors from the coniferous and mixed forests of Canada and the northernmost continental United States.
Yellow-bellied Sapsuckers drill evenly spaced holes which they repeatedly visit to harvest “sap” and the insects that become trapped therein. These surgically small excavations penetrate only the bark and the phloem, a shallow, spongy layer of the trunk that carries sugars from the leaves to other parts of the tree. Seldom do they puncture the thin, underlying cambium layer which protects the true sapwood. After healing, sapsucker holes leave linear rows of small scars which are sometimes still discernible decades after a bird’s final visit. This adult male will probably linger in the Lower Susquehanna River Watershed until colder weather renders the tree totally dormant, the flow of “sap” ebbs, and small insects become harder to find. Then he’ll make his way off toward southern forests of oak and pine for the remainder of the winter. Sapsuckers work their way north as sugary “sap” begins flowing again in the spring.
The Hermit Thrush is another denizen of coniferous and mixed forests. In habitats with dense cover and sufficient food sources like fruit-bearing shrubs and vines, some will remain through the winter. The Hermit Thrush is the only spot-breasted thrush regularly seen in our region from November through March.
Almost the size of a thrush, the largest of our native sparrows, the Fox Sparrow, is currently at the peak of its southbound migration. While taking a break from their nocturnal flights, some may stray from forest edges to visit suburban feeding stations. Most leave our area by mid-December, then begin returning north as early as mid-February.
Not present every year, flocks of Pine Siskins are beginning to arrive in the lower Susquehanna region. They are currently most common along the mountain tops of the Ridge and Valley Province where they are feeding on the seeds of the Sweet Birch, a tree also known as Black Birch. Look for them around niger seed feeders and on the prickly seed balls of cultivated American Sweetgum, but don’t be surprised if they quickly pass us by to spend the winter on the Atlantic Coastal Plain to our south where this native tree grows in abundance.
Since late October, Purple Finches have been widespread throughout the region. These female/juvenile male types are frequently being seen at feeders, particularly near woodlands and other areas with stands of conifers.
Less frequently seen are the adult male Purple Finches in their raspberry-colored plumage. What a dandy.
While right now is the best time to get out and look for these species from the northern forests, any or all of them could linger into the winter months, particularly where the food supply is sufficient and conifers and other evergreens provide cover from the blustery weather.