Nature Notes: Territorial Tunes
I spent the first “spring heat wave” of March exploring the backwaters of the Mississippi River in the Trempealeau Wildlife Refuge. Down here in bluff country, the Mississippi flows between the breathtaking bluffs of Minnesota and Wisconsin. The marshland and backwaters provide critical habitat for many animals, especially migrating birds. Temps soared to 53 degrees on Sunday, March 4th (before crashing back down and bringing 6 inches of snow on Monday). The river was a welcome rest stop for weary travelers. Recently, I’ve been walking a lot on the wonderful trails through this park and I’ve found my own refuge in the silent, peaceful winter paths. I wasn’t long into my walk on Saturday before I realized it would be anything but silent…
For the first time in months, the sound of silence was shattered by the return of some of our noisiest feathered friends. A cacophony came from overhead, as huge V’s of geese came streaming from the south. In between the loud honks came the whistling of duck wings, accompanied by their quiet, chuckling quacks. A smile spread across my face every time the vociferous calls of the sandhill cranes rose above the rest. In fact, their loud, bugling call can be heard from two and a half miles away! While my eyes scanned the skies to locate the origins of all these wonderful sounds, I saw eagles soaring over the bluffs, ice, and water in nearly every direction.
Competing with all the noise of those larger birds were the red-winged blackbirds. As I looked out towards the dry vegetation sticking out of the still-frozen water, I saw many of the reeds had a black bird perched on top, calling out in defense of their territories. They were relentless, resting for only seconds before calling out their trills again. So what’s all the fuss about?
All the birds I heard singing were male red-winged black birds. Males are distinguished from females by their bold colors – black with bright red and yellow “epaulets” or shoulder patches. The males arrive back in the north before the females. Here, they face the freezing temps of a lingering winter in order to claim and defend the best breeding territories. They perch on a tall stalk, shrub, or tree and do what is known as a “song display”. The male fluffs out his feathers and spreads his tail to look larger, lifts the edge of his wing to flash his red epaulets, and sings out a loud trill. This lets the other males know “back off, this is my turf.” They also do this in flight above their territory.
In addition to keeping other males away, this is how he will attract females when they return to the area in a few more weeks. When the females arrive on the scene, they’re looking for males who have claimed habitat with enough food (mostly insects), water, and safe nesting places in the tall grass. Older males tend to have larger, better quality territories, and therefore tend to attract more mates than younger males. This is known as resource-defense polygyny in birds (a male protects a large enough area to provide adequate resources to support multiple mates). Red-winged blackbirds are often seen chasing much larger birds, such as crows and even hawks or eagles, out of their territories!
As I stood there and watched, it occurred to me how different this walk was compared to my last, silent encounter down the same trail. The calls of these birds gave me renewed energy and a feeling that spring was here! I couldn’t help but feel that these birds were just as excited as I was about it. After all, they were singing out at full volume to alert the world they had returned. In near-by fields, the sandhill cranes could be seen leaping with joy for their return! I’m kidding; though it certainly looks that way. The hopping around is part of a spring mating ritual for the cranes. But it sure does add some entertainment to the scenery!
Even after the temperatures dropped and the snow came, these birds can still be seen on the landscape. They stay through the cold and the snow, and await warmer temps. Geese and cranes can be seen feeding in fields during the day. You may also find pairs of geese, already defending their territories. They’re also not afraid to let their presence be known! Red-winged blackbirds can be seen feeding at bird feeders and along roadsides while they await warmer days and insect meals. If you live near water, you can help them out by putting out a birdfeeder! Once insects are plentiful in the warmer months, they’ll likely stop visiting. Ducks and swans can be found, tail-side up, foraging underwater in the open patches of water between the ice. These early spring migrants survive the frigid temps and food scarcity all for the sake of their offspring. They’re here to establish the best territories with the safest nesting spots and the most food, all so their young have the greatest chance of survival.
So head outside this month and watch as they return or pass through! Enjoy the symphony of their calls, the movements of their mating rituals, and the ceaseless way they defend what they’ve worked so hard to acquire. It truly is a sight to behold! As always, enjoy!