August 6, 2008
By Susan Benson,
CNHM Director of Education
“Today is August first, and I woke up to the terrific “chatter” of what sounded like hundreds or thousands of birds. Were they starlings in my back yard? Robins? Then it hit me – the red-winged blackbirds were already congregating. For the past three years, I’ve seen these birds in large numbers, always in early August, ensconced in my large pines, singing merrily. Am I lucky enough to have my backyard on their migratory pathway? Is there some other reason? The curious scientist in me had to explore.”
– From my phenology journal
Fall migration in the northwoods for red-wings begins in mid-July as birds disperse from their nesting areas to form loose flocks. The numbers gradually build through August reaching peak abundance during September 10-25. During this period, roost flocks ranging up to 50,000 individuals can be observed. Most fall migrants have departed by early November with a few stragglers hanging around through December. Some of these roosts will also include other bird species such as European starlings. Here we are in the sweet summer heat and weather, and I’m saying a fond farewell to our red-winged blackbirds!
When next spring comes around, the male red-wing is often one of the first migrants to arrive in our area. The male fiercely defends his territory during the breeding season, spending more than a quarter of all daylight hours in territory defense. He keeps other males out of his territory and defends the nests from predators. Humans wearing a red jacket into a marsh in the spring, should not be surprised to be attached by this fierce defender. Birders have seen the males chase crows, great blue herons, deer, and other birds as well. When singing to defend their territory or to attract a female, the male fluffs the red decoration and half-spreads his wings to show off the red and look his best. The red-winged males can also have up to fifteen different females making nests in his territory. A high percentage of territorial males have more than one female but, up to one-half of the young in "his" nests do not belong to the territorial male, having been sired by neighboring males.
We can continue to enjoy this bird species, as the red-winged blackbird is possibly the most abundant bird in North America. If you have your own red-wing observations to share or other interesting observations, please email the Museum at firstname.lastname@example.org.
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