Take a glance at your feeders on a winter day and you might see chickadees and cardinals snatching up sunflower seeds, goldfinches dining on nyger seeds, woodpeckers chipping away at suet and juncos and sparrows scooping up spills on the ground.
It looks harmonious, even friendly, but looks can be deceiving in the natural world. While birds spend less time defending territories in winter, their tendency to flock up seems to compel them to play by strict rules. And even small birds that seem to be without many defenses are protected by social orders and carefully defined roles.
Watch carefully as two chickadees arrive at a feeder at the same time. You may notice that one bird chases the other away or eats seeds while the other is forced to wait. What you're seeing is a chickadee social hierarchy, a pecking order in action.
In fact, that flock of chickadees in your back yard is organized as rigidly as a wolf pack.
One pair -- usually the oldest male and female -- dominates the others in the flock, which usually includes six to 10 birds in winter. The alpha pair demands -- and gets -- the best access to food, which, in turn, gives it a nutritional edge and the best chance of surviving the winter.
There's also a beta pair, then lesser-ranked pairs, plus several floaters (birds that were hatched within the year). Lower-ranked birds defer to higher-ranked birds, especially when they're bunched up at feeders.
But status within the flock can change. There always are opportunities for social climbers to move up if a vacancy opens when a bird disappears. And even birds at the bottom of the pecking order benefit from being in a flock. Subordinate birds often claim a mate and a spring breeding territory by attaching themselves to a flock. And having more eyes looking for food and predators helps the whole flock.
Cardinals know thy place
A winter flock of cardinals is a temporary gathering of adult pairs and juvenile birds. Its makeup changes continuously because birds join and drop out as the flock moves around. But cardinals don't seem very aggressive in winter. That's probably because these birds know their place - which is based on age, gender and possibly the quality of their plumage.
A circle of snowbirds
Dark-eyed juncos, also known as snowbirds, seem to hop busily on the ground in search of seeds. But if you look closely, you may notice that the dominant birds spend much of their time in the center of a flock, while lower-ranked birds are on the periphery.
A very hungry bird may attempt to move closer to the center, but a dominant bird will drive it back by lunging at or chasing the intruder.
By now, goldfinches have molted to become "taupefinches," both males and females wearing the same drab colors once the breeding season has passed. While we may not be able to tell male from female, the birds can. Males have a higher rank than females in the flock, and adults lord their position over young birds.
However, most flocks of goldfinches we see in winter are composed of young birds hatched this year. Our summer goldfinches are spending the winter south of here in large flocks made up of primarily adult birds.
Val Cunningham, a St. Paul nature writer, can be reached at firstname.lastname@example.org.