If you keep a winter bird feeder, you might have noticed that blue jays often seem to dominate the scene, grabbing up more than their fair share of seed, and bullying other birds away.

Where does this behavior come from?

Blue jays might be bullies, but they're not anti-social, at least not among other blue jays. In fact, some of their bullying is a direct result of how well blue jays are able to get along with each other.

Blue jays are one of the so called "New World Jays," and most of the other species in this group are tropical. We can learn a lot about a blue jay's winter behavior by studying its southern cousins.

One close relative is the Florida Scrub Jay. These jays eat the acorns of the scrub oak, which grows in Florida in isolated stands. To best exploit this food source, scrub jays form tight knit social groupings of related birds. Each oak stand is zealously guarded by a single group of scrub jays.

In the summer, blue jays spread, and act pretty much like other birds. However, in the winter they band together like scrub jays to form tight knit flocks. Although there may be no isolated stands of scrub oak to guard, there is usually something even better, your back yard bird feeder! A blue jay flock forms an elaborate pecking order around the feeder, often waiting in well-mannered lines to stock up, fly away, and like many other jays, horde their loot in secret caches.

If you've noticed that smaller birds seem to shy away when blue jays take over your feeder, they have good reason. Territorial blue jays will sometimes kill and eat smaller birds that stray onto their turf.