Home & Garden

Birds’ mating season breeds territorial behavior

March brings a marked increase in nesting preparation and bird movement. Many species are already moving through on their way north, while others may already be on nests. Readers’ reports reflect this, so I thought I would relay to everyone the newest developments.

With the breeding season comes an increase in territorial behaviors. A common behavior for birds is attacking their own reflections in windows and car mirrors. The aggressive bird thinks it is seeing an intruder in its territory. They can make a real mess because part of the strategy to drive off the intruder involves defecating on it. Talk about fighting dirty. But it does mean there is a nest nearby, or soon will be, so your habitat is preferable. The species that most commonly exhibit this are northern mockingbirds, northern cardinals, eastern towhees, and eastern bluebirds.

I receive many questions about bully northern mockingbirds. These birds are very territorial and often will attempt to dominate feeders, chasing away the other birds. Unfortunately, there is not an effective means of discouraging the mocker without discouraging other birds, too. Perhaps spreading the feeders around the yard will give the other birds a better chance. The mockingbird can’t defend all the feeders all the time. Mockingbirds won’t eat seeds but do like suet dough. If you offer this, maybe removing it from the menu can help.

If you feed birds, you may notice an influx of black birds patronizing for the next few weeks. Most of these birds are red-winged blackbirds heading back north. Look for a cream-colored stripe on the shoulder of the darkest birds, the males. The paler, striped birds are the females. First-year males may be in a combination plumage as they molt into adult plumage during their journey.

You may see some brown-headed cowbirds, too. The females are plain gray-brown. The males are a bit more distinctive, with a shiny black body and a brown head.

Each week should bring something new in bird arrivals or behaviors. Let me know what you are seeing.