Those raucous red-winged blackbirds are back

Red-winged blackbirds are back – spring is here! The males come back in big flocks, sometimes accompanied by grackles and cowbirds. These big flocks are raucous, making a racket as they perch in trees or walk around on lawns or fields. They poke around in the grass, finding grubs, insects or seeds on the ground. Studies of the contents of red-winged blackbirds’ crops or stomachs have shown that 75 percent of their food is vegetation and 25 percent is insect material.

They have wintered in large flocks in the middle of the United States, mostly in farming areas where food is plentiful. Now the male red-winged blackbirds are looking for wetlands in which to establish a territory, usually a cattail marsh or a shrub swamp. Each male establishes his territory by showing off his beautiful red-and-yellow epaulets, singing his oak-a-lee song and taking up aggressive chases. The male chases other red-winged blackbirds off his territory.

Once, when I was teaching field ornithology, I made a model of a male red-winged blackbird, put it on a post in a marsh and played a red-winged blackbird song nearby. Immediately the nearest male red-winged blackbird came over and knocked the model off its post! The students were amazed.

The female red-winged blackbirds, which are brown with streaks, arrive after the males. They often come to feeders, confusing those who feed birds and think these arrivals are big sparrows of some sort. Female red-winged blackbirds can be identified by their size – considerably larger than most sparrows, rusty-beige throats, the rusty-beige stripe above and behind the eye, and thin pointy bills.

When the females arrive at the wetlands where the males have established their territories, mayhem ensues. Each male tries to attract as many females as possible to his territory. The females check out each territory and each male.

The male tries to “own” the females in his territory. However, DNA studies of the eggs and the adult birds have shown that 30 percent of females manage to mate with a male in another territory.

When you look across a marsh of cattails in May, it looks as though it is full of males chasing each other. But where are the brown-striped females? They are down in the cattails, being discreet, hiding their secrets.

For information on Fields Pond Audubon Center, call 989-2591.