The Strange Courtship of Prairie Grouse
At times I think that April is my saddest month. The last of the sandhill cranes are leaving the Platte Valley for northern breeding grounds. As I watch the last flocks disappear into the clouds like departing angels singing a final farewell, I am bereft, knowing that I will not see or hear them again for six months. My primary consolation lies in the fact that I know I will soon be hearing a different chorus, a sunrise serenade of grassland dancers, just as mysterious and beguiling as the departing cranes. But to hear and see this annual event requires more planning and even more patience than is needed for watching cranes.
At least for Lincoln or Omaha residents, one must leave by about 3:30 a.m. to drive the eighty-odd miles into southeastern Nebraska, where native prairie grasses still grow thick over glacial-molded hills. Then, in total darkness, one must find the right county roads and locate the best stopping point for setting up a blind. After setting up the blind in the dark, one must insert into it both oneself and all the necessary paraphernalia, such as a flashlight, binoculars, camera, spare lenses, tripod, gloves, a coffee-filled thermos, a stool, and perhaps a small tape recorder. Almost always the best place for a blind’s location is atop a hill covered with low prairie grasses, at least several hundred yards away from tall trees or thick shrubbery and a quarter mile or more from any occupied dwellings. An advance scouting the day before, with critical odometer information recorded and the setting up of a few yellow flag markers to show the best predawn walking route, often makes the difference between finding the exact site and an entire morning’s efforts wasted. Recent bird droppings and scattered grouse feathers provide the best clues to judging the center of mating activity.
If all goes well, one is settled in the blind at least a half hour or more before sunrise, before the eastern sky begins to brighten and the surrounding landscape features begin to take shape. If there is a full moon, an even earlier predawn arrival is needed, whereas a cloudy sky will mean that the curtain rising for the dawn serenade will be somewhat delayed. Then one must quietly wait, listening for early rising coyotes or perhaps the last great horned owl duet of the night. This is a time to be thankful for the preservation of these prairie relicts of the past—almost nowhere else in North America are there still countless locations where, without making reservations or paying a hefty viewing fee, one can watch and hear the dawn dance of the greater prairie-chicken.
I have called the greater prairie-chicken the spirit of the prairie; few other birds are so closely associated with native tallgrass prairies or are so sensitive to their destruction. It is a bird the color of autumn grasses, its feathers disruptively patterned in vertical stripes of switchgrass buff and Indiangrass brown, so that a motionless prairie-chicken simply fades into its background. Only its normally hidden under-tail coverts are conspicuously white. Also completely hidden beneath the elongated neck feathers of adult males are two patches of bright orange-red skin. Like secret signals, these areas are exposed only during the dawn and dusk mating ceremonies of prairie-chickens, when the males fill their throats with air, inflating the orange air sacs on each side of their throats and causing each side of their necks to resemble half tangerines. As these air sacs are expanded, the male utters a mellow and low-pitched cooing, something like that produced by blowing across the top of an empty bottle, but in a three-part cadence sounding to me something like Old-Mul-Doooon. Although this vocalization is soft, it can be heard for a mile or more under ideal conditions. The male also simultaneously stamps his feet rapidly, producing a soft drumming sound, and quickly fans and closes his tail feathers during each call sequence. While displaying, the male erects his long neck feathers so that a pair of ear-like appendages are formed on each side of his head and also tilts his tail vertically, exposing white under-tail feathers. This dramatic transformation of the bird’s appearance, movements, and sounds produces a hypnotic effect on humans and, it would seem, on female prairie-chickens, for whom it is intended.
When the females arrive on the mating grounds, usually at about sunrise, they begin to inspect each male carefully, moving around the group like housewives searching for the best Thanksgiving turkey, but giving no outward indication of their possible preferences. The males in turn ratchet up the speed and intensity of their displays as each female approaches, and it is probably the relative vigor and perfection of an individual male’s display behavior that helps females make their final mating choices. Not only are the males’ minor display variations a possible basis for female choice, but of equal or greater importance is each male’s relative position among the other males, a reflection of his ability to defend and maintain a desirable territory. Socially dominant and centrally positioned males (“master cocks”) are often at least four years old and are the most effective at attracting and successfully mating with females. Indeed, even among a group of twenty or more interacting males, a single highly experienced and socially dominant male is likely to obtain at least 80 percent of all matings.
Many other open-country grouse, such as the North American sharp-tailed grouse, greater sage-grouse, and European black grouse, perform similar communal courtship ceremonies. These highly localized and strongly competitive congregations of displaying males are called “leks,” and their behavior is called “lekking,” a Scandinavian word meaning to flirt. Lekking behavior appears to function biologically as a means of making certain that only the fittest males are able to attract mates and propagate the species’ genetic line. Such a selective function requires an ability by females to rapidly and accurately assess all the males and likewise stimulates males to develop ever more effective ways of competing and attracting females. This process, called sexual selection, was first described by Charles Darwin and helps explain the evolution of such male traits as exhibiting conspicuous feathers or exposing colorful skin, uttering complex vocalizations, and performing extravagant postural displays from which females might select. It also accounts for the presence of such traits as antlers, horns, beards, and aggressive behavior among male mammals. Darwin realized that sexual selection may work reciprocally, with females detecting and choosing the most virile and strong males on the basis of such “secondary” sexual traits. Males likewise increasingly evolve traits making the fittest individuals able to outcompete other males, either through intimidation and physical dominance over others or by being more sexually attractive than other males. Over time, these interacting mating attributes produce ever more conspicuous sexual differences in adult behavior and appearance. Darwin hypothesized that our most refined human traits, such as having an aesthetic sense of beauty and a love of music, are ultimately attributable to sexual selection, and he even slyly inferred that women “first acquired musical powers in order to attract the opposite sex.”
It is easy to forget about the theoretical basis for (and the human counterpart of) lekking behavior when watching prairie grouse and instead simply to become immersed in the action. One can detect spatial and behavioral differences among the males, as their territorial boundaries become apparent, and realize that some males are more self-assured, more aggressive, and more active than others. Thus it becomes easier to accept the idea that females are indeed able to choose desirable mating partners rapidly. Mating itself is brief and might be easily overlooked if one is not paying close attention. After a successful mating—and only a single mating is needed for a female to lay a clutch of twelve or more fertile eggs—the female leaves the lekking ground and begins to search for a nest site, which may be as far as a mile or so away. She will not interact again with males or other females until her brood is grown and autumn flock formation begins.
In Nebraska the males continue their daily display activities with diminishing enthusiasm until well into May, with some of the late matings probably the result of females having lost their original clutch and attempting a second nesting. The males play no roles in chick rearing or other familial duties. After a summer of molting and foraging, the older males usually return to the lek in early fall, apparently to reclaim possession of their spring territories or perhaps try to expand into space made available by the deaths of others. This fall display activity also attracts the attention of young males, who may become peripheral viewers or even minor participants. As each male grows older and more experienced, he is likely to move his territory ever closer to the middle of the lek, with the potential of eventually becoming a master cock if he lives long enough.
There are several possible options for visiting a prairie-chicken lek. Prairie grouse are probably most common in the eastern and central Sandhills, where optimum survival conditions are provided by a combination of native Sandhills prairie and access to corn and other crops that supplement winter foods. Public-access leks with ready-made blinds are available on a first-come, first-served basis at the Bessey Ranger District of Nebraska National Forest in Thomas County and at Valentine National Wildlife Refuge in Cherry County.
Commercial operations that offer views of prairie-chicken and sharp-tailed grouse leks in the relative comfort of permanent or school bus blinds are provided by the Switzer family at Calamus Outfitters, near Burwell, and by Mitch Glidden at the Sandhills Motel in Mullen. In southeastern Nebraska, the Big Blue Ranch and Lodge, located three miles west and three miles south of the village of Burchard and operated by Scott and Billie Kay Bodie, offers spring trips to a prairie-chicken lek as part of a lodging package.
No Nebraskan should consider his or her life complete without experiencing these drums of April. Like watching a star-filled Sandhills sky, seeing sandhill cranes in formation above the Platte, or canoeing the Niobrara River, it is a defining experience of life on the Nebraska prairie.