The Dark-eyed Junco is currently divided into six distinct populations: Slate-colored (Canada & East Coast), Oregon, Pink-sided, White-winged, Gray-headed, and Red-backed Juncos.
In Bucks County we see the Slate-colored Juncos, often called “Snowbirds” because of their coloring - white belly plumage and slate-colored back of the junco suggests “leaden skies above, snow below.”
Dark-eyed Juncos tend to return to the same area each winter. Chances are that you have many of the same birds at your feeder this winter that you had in previous years.
To avoid the competition, many female juncos migrate earlier and go farther south than most of the males. In Michigan only 20% of the wintering juncos are females, whereas in Alabama 72% were found to be female.
Male juncos tend to spend the winter farther north in order to shorten their spring migration and thus gain the advantage of arriving first at prime breeding territories.
Each winter flock of juncos has a dominance hierarchy with adult males at the top, then juvenile males, adult females and young females at the bottom. You can often observe individuals challenging the status of others with aggressive displays of lunges and tail flicking.
The southward migration of Slate-colored Juncos is complete by early December.
Juncos have over 30 percent more feathers (by weight) in the winter than they do in summer.
Juncos prefer to roost in evergreens at night but will also use tall grasses and brush piles. They return to the same roost location repeatedly and will share it with other flock mates, but they do not huddle together.
According to Project Feeder Watch, juncos are sighted at more feeding areas across North America than any other bird. Over 80% percent of those responding report juncos at their feeders.
A study in New Hampshire on the foraging habitats of the Slate-colored Juncos found that they spent over 65% their time on the ground, 20% in shrubs, 16% in saplings or low trees. They were never observed in the canopy of large trees.
Juncos are known to burrow through snow in search of seeds that have been covered over.
You may not like these weeds in your yard, but the seeds of chickweed, ragweed, knotweed, pigweed, lamb’s quarters and crabgrass are some of the main natural seed sources used by juncos.
You can attract juncos to your yard by feeding a seed blend containing millet and hulled sunflower seeds.
Fun Facts About Juncos