Window On Nature
By Lowell and Kaye Christie, F47246
Discover some of the weird and wonderful ways birds go about finding a mate.
Tap, tap, tap. Tap, tap. Experts say you can tell what a woodpecker is doing by listening to the speed and frequency of its drumming. Tap, tap, tap. Quiet, irregular drumming occurs when the bird is harvesting insects. Thunk, thunk, thunk. Slow, steady hammering is associated with excavating a woodpecker hole. Thunk, thunk. Chiseling through all that wood is an exhausting and noisy activity.
Rat-a-tat-a-tat-tat-tat. Fast drumming is used to stake out a territory, or to show off to a member of the opposite sex. But no interpretation was necessary on one particular spring morning when we heard an unusual sound coming from our motorhome’s roof. There, a woodpecker was drumming his bill against our TV antenna. Now, we know there aren’t any insects burrowed inside the framework of the antenna, and it really wouldn’t make a very good nesting location. But metal does become a nice sounding board for a critter that wants to make noise and attract a mate, which is exactly what this woodpecker was up to.
At this time of year some early birds have already paired up, while others are actively seeking companions. It’s breeding season throughout the country, and the best time of year for avian behavior watching.
Quite a few birds are just as noisy and outgoing as the woodpeckers. Some rely on extravagant displays or dances, such as cranes and grouse. And even the most common birds often will surprise you with unexpected activity. With all their attention on the opposite sex, many of these birds are nearly oblivious to observers. You’ll be amazed by what you can see.
Probably the most extravagant courtship displays come from the tallest of North America’s birds, the whooping cranes. Standing 5 feet tall, these birds are white except for their black wingtips, “mustache,” and the small patch of red on their crown. They mate for life; their calling and dancing helps to preserve their bonds.
The “whoop” in their name may have come from the unison call they perform. A female crane stands upright, holding her bill high to extend her height, and starts the duet by uttering two high-pitched whoops. The male imitates the posture, but also raises his black-tipped wings over his back as he responds with a single lower-pitched whoop. Back and forth they go, the interchange occurring so fast it almost sounds like a single individual, but with the female calling twice as often as the male.
The whooping crane’s display dance is even more fanciful. It can include jumping, bowing, and running; the tossing of sticks or grass; and wing flapping. Imagine an acrobatic dance performed by two of the tallest birds on the continent. Better yet, imagine a mass of these birds performing the same dance. When one bird in a flock starts to perform, it seems to be contagious, as others begin mimicking the behavior.
Whooping cranes are an endangered species, so they can be hard to find in your neighborhood, but according to the International Crane Foundation, all of the crane species perform display dances. Fortunately, another North American crane species, the sandhill crane, makes its home in 39 states. This species is only slightly smaller than the whooping crane and has similar calls and displays.
The size of a bird certainly doesn’t limit its seasonal expression of love. At the opposite extreme are the hummingbirds, the smallest of our flying friends. Sixteen species of hummers breed in North America, and some of the males put on quite a display to impress the opposite sex. In the East you’ll usually find the ruby-throated hummer, and as you travel south and west the number of species multiplies.
The most studied hummingbird is the Anna’s, a year-round resident of the western United States. During mating season the male Anna’s hummingbird, a tiny critter that weighs less than a nickel, puts on a surprising aerial display. To impress his prospective mate, the bird spirals upward to a height of more than 100 feet, and then plummets at top speed directly toward the ground. By the time he reaches the bottom of the dive, the bird is moving at 50 miles per hour. Then spreading his tail feathers for control, he pulls out of the dive right in front of the female.
As the hummer reaches the bottom of the arc he creates a loud sound, sometimes described as a pop or chirp. Until recently it was thought the sound was vocal, but researchers at the University of California at Berkley have used a high-speed video camera (500 frames per second) to show that the noise is created by rushing air striking the outer tail feathers.
Not only does the hummingbird call attention to his display with sound, but he also positions himself at the precise angle where the sun will produce an iridescent glow on his feathers. No sense taking any chances when it comes to acquiring a family.
One of our favorite spring displays is the water dance of the western grebe. The western is the largest of the grebes, its long and slender white neck strikingly edged in black. It is sometimes called the swan of the grebe world.
One of the western grebes’ displays consists of synchronized head-bobbing as they extend their long necks and then quickly curve them into an “S” shape, twisting until the yellow bills touch their backs, then extending their necks and starting again. This can go on for several minutes, and sometimes turns into the more spectacular display called rushing.
The male and female grebe look at each other, then suddenly explode across the water side by side, moving their feet so fast that their bodies are pushed completely up in the air. Their wings are swept back, their necks and bills extend upward, and water spurts up behind them like the wake of a speedboat. The pair may travel as many as 50 yards, so close together they almost touch, ending the mad dash with a synchronized dive beneath the surface of the water. Sometimes you can see multiple pairs rushing at the same time.
This season you can find examples of avian attraction almost everywhere: mallard ducks doing their heads-up, tails-up display; bufflehead ducks in their “water-skiing” pose; nighthawks booming as they dive toward the ground; the common snipe making a drumming sound as he rushes through the air; the wild turkey gobbler fanning his tail as he struts before the females.
Get outside, look, and listen. And don’t forget your binoculars.