15 March 2023

The guys are back in town! Male red-winged blackbirds returned to western Pennsylvania early this month to get a jump on the breeding season. Males arrive 2-4 weeks before the females in order to shake down who owns what territory before the ladies get here.

The best territories are in the middle of a marsh and claiming a good one is extremely important. When the females arrive they chose a mate based in part on the quality of his territory. If the male and his territory are exceptional, up to 15 females join his harem.

According to Birds of the World, experiments have shown that females prefer a harem on good territory to being the lone mate of a male on poor territory. Female red-winged blackbirds would rather be one of many wives than alone with one male in a lousy home. With that in mind the males are getting ready to set up their harems.

Watch for the arrival of female red-winged blackbirds in late March or early April. You’ll hear the boisterous clamor of males when they see the flocks of females.

This 3-minute video shows red-winged blackbird behavior in the spring.

(photo from Wikimedia Commons, video from Cornell Lab of Ornithology on YouTube; click on the captions to see the originals)