Fun Facts: Blackbird Epaulets
Red-winged blackbirds are one of the most familiar and widespread birds in North America, but being so abundant, they don’t get much love from birders. The majority of the birders I meet are focused on adding new birds to their life lists, so they seem uninterested in “everyday” birds like sparrows, mallards, and blackbirds.
Common or not, red-winged blackbirds still manage to get my attention with their striking colors and distinctive calls. Blackbirds are year-round residents where I live, but I tend to notice them most in the spring, because the males are much more vocal when they are staking their territories.
Once they’ve claimed a territory, male red-winged blackbirds do something called a song spread display where they hunch forward, repeat their call, fan out their tails, and puff up their wings.
The song spread display is one of the best times to observe the male blackbird’s wing markings, which are known as epaulets due to their resemblance to the shoulder pieces worn by soldiers. Displaying these markings helps the male defend his territory and attract potential mates.
To learn more about the function of epaulets, scientists conducted a study where they darkened the epaulets of some male blackbirds. They found that the males with less prominent epaulets were much more likely to lose their territories. Similarly, blackbirds defending their territory against intruding males will base the intensity of their defense on the size of the encroaching bird’s epaulets. So the epaulets are a signal of the male bird’s status and strength.
Another fun fact: blackbirds can also make their wing markings less noticeable. When males are perched outside their territory or feeding as part of a larger group, they conceal the red patch and show only the strip of yellow beneath it. Blackbirds are highly social, often congregating and traveling in flocks that can number in the thousands, so this behavior allows them to coexist peacefully in social situations.
Epaulets are far less important for female red-winged blackbirds, who have streaky brown plumage. Females spend a lot of time on the ground or in tall reeds and grasses in marshy areas, and their plumage helps them blend right in.
Baby blackbirds start off with a similar streaky brown appearance. I was lucky to spot a mother blackbird feeding this little one near the edge of a wetland and caught a few photos while mom was busy searching for more food. There’s something so goofy and vulnerable about baby birds. I love it!
Common birds may not inspire the same level of excitement as rare birds, but like most things around us, they are still quite interesting if we take the time to get to know more about them. The next time you see a male red-winged blackbird, for example, you can watch his epaulets and see if he's feeling territorial or a little more relaxed and sociable.