Common Redpolls seen in Lehigh Valley region

Common Redpoll (male)

The Common Redpoll is anything but common in the Lehigh Valley. The last recorded sighting was a decade ago in Whitehall. But that drought of sightings ended last week with the visit of two Common Redpolls to the Lehigh Valley region.

The Common Redpoll is a small brownish-gray finch that breeds just south of the Arctic Circle of northern Canada and Alaska. They are easy to distinguish from Purple Finches or House Finches which are seen routinely in our backyards.

The redpolls spend their summer in the tundra and in forests of birch, poplar and pine. In the treeless tundra, they find hollows or shrubbery in which to roost, nest and breed. The pickings are great. They primarily eat seeds of grasses, sedges, catkins, buttercups, mustard and other wildflowers. They also consume spiders and insects, which thrive in the brief summer.

Winter is much tougher. Temperatures can fall to minus 65 degrees Fahrenheit. Common Redpolls forage for brief periods, filling their esophagus with seed, then tunnel as much as a foot deep into the snow to digest the food and stay warm. Subsisting almost entirely on a diet of bird seeds, they consume up to 42 percent of their body weight every day. Despite the extreme weather, redpolls number in the millions and their population is thought to be thriving.

Compare: House Finch

Scarcity of food—not the extreme cold—drives Common Redpolls to migrate to the United States, occasionally as far south as Maryland and the Ohio Valley. Even so they are not often seen this far south. Birders in the Lehigh Valley may go many years without spotting a single Common Redpoll.

But this week birders were treated to the appearance of two Common Redpolls, one on January 9 near Air Products in Trexlertown and another one on January 15 at the Tohickon boat access at Lake Nockamixon.

The previous recorded sighting was in Whitehall in 2004, according to Birds of the Lehigh Valley and Vicinity, the authoritative guidebook published by the Lehigh Valley Audubon Society.

Compare: Purple Finch

Common Redpolls can be distinguished from other finches. House Finches and Purple Finches are larger than Common Redpolls. Those finches' beaks are heavier and lack bold wing bars. The male Common Redpoll has small patches of reddish color whereas the other finches have red or pinkish red covering most of the crown and chest. Goldfinches in winter wear an olive tone and lack the red of redpolls. Another related backyard bird, the Pine Siskin, has some red but is darker overall and more heavily streaked. No white is visible. Their beaks are longer.

In winter, Common Redpolls frequent willows, open conifer forests and open, weedy fields. They even will visit backyard bird feeders. You're not likely to see one, but it's worth keeping your eyes open just in case!