One aspect of animal behavior that fascinates me more than anything else is lek mating. Leks are gatherings of males who engage in courtship displays and territorial battles to gain access to mating rights with onlooking females. Although lekking behavior is found in a wide range of vertebrates including fish, amphibians, reptiles, and mammals, it is most prevalent among birds. Indonesia’s Birds of Paradise and South America’s Manakins and Cotingas are famous examples of lekking species. Here in North America, the family that draws most attention for lekking is the grouse family, Tetraonidae.
A male Greater Prairie Chicken (Tympanuchus cupido) displays on a lek outside of the town of Wray, Colorado
Colorado is home to seven species of grouse: Greater Sage Grouse, Gunnison Sage Grouse, Sharp-tailed Grouse, Lesser Prairie Chicken, Greater Prairie Chicken, Dusky Grouse, and White-tailed Ptarmigan. The first five of these species exhibit classical lekking behavior, where males gather in close quarters to display for females. Only the most dominant males are selected by females, at which point copulation occurs and the female flies over a mile away from the lekking site to incubate the eggs and raise the chicks on her own.
The latter two grouse have different mating systems. The Dusky Grouse exhibits dispersed or exploded lekking, in which displaying males are somewhat clustered within suitable habitat but each male still has a rather large territory.
Dusky Grouse (Dendragapus obscurus) crossing the trail near Hidden Valley, Rocky Mountain National Park
At the opposite end of the spectrum, the White-tailed Ptarmigan is completely monogamous and does not lek at all.
Most of these grouse have shown dramatic declines in population, largely due to loss of habitat from agriculture. Gunnison Sage Grouse, a species separated from the Greater Sage Grouse in the year 2000, is the most threatened out of all the Colorado Grouse. Not far behind are the Lesser and Greater Prairie Chickens. Lesser Prairie Chickens are considered a Tier-1 species of greatest conservation need while Greater Prairie Chickens are considered a species of conservation concern.
In Colorado, the Prairie Chickens occur in the high plains of the East, the Greater Prairie Chicken in the northern mixed-grass prairies associated with sand sagebrush (Artemisia filifolia) and the Lesser Prairie Chicken in the southern plains associated with drier habitats. The Greater Prairie Chicken is separated from the Lesser by being larger and having a yellow-orange (instead of a red-purplish) tympanum on the neck. They are also distinct in their lekking behaviors. Both were once widespread and abundant throughout the Great Plains. In fact, the Blackfoot, Shoshone, Sioux, and Cheyenne Indians developed sacred dances that mimicked the courtship rituals of the Prairie Chicken males, fluffing feathered head-dresses, strutting, stomping the ground, and moving forward and spinning around in circles.
Indigenous dances were inspired by the courtship rituals of Prairie Chickens (Photo: Jen Doerksen)
I had been wanting to see Prairie Chickens for quite some time, so I convinced Angie to travel with me to the little town of Wray, Colorado close to the Nebraska and Kansas borders. Wray is located in the sandhill region of the Great Plains, an area that spreads across western Nebraska, western Kansas, eastern Wyoming, and southern South Dakota.
The location of Wray, Colorado in eastern Colorado
The World Wide Fund for Nature (WWF) designated the Sandhills as an ecoregion, distinct from other grasslands of the Great Plains. As much as 85% of the ecoregion is intact natural habitat, the highest proportion of the Great Plains. The region sits on top of the Ogallala Aquifer, the western and northern reaches of which are dotted with small lakes and wetlands. It is characterized by various sand dunes, some as high as 330 feet in height, and extensive mixed grass prairies dominated by sand bluestem (Andropogon hallii), sand sagebrush (Artemisia filifolia), prairie sandreed (Calamovilfa longifolia), and needleandthread (Stipa comata).
Unlike many other birds, you can’t just expect to go to the right habitat to see Prairie Chickens. You need to get permission to visit a known lek, most of which are on private property. After some searching online, I came across the name of Bob Bledsoe, owner of the Bledsoe Ranch and Cattle Company. I gave Bob a call, doubtful he would be willing and able to accommodate. Much to my surprise, he was willing to bring us to the location of a lek we could access with our two-wheel drive sedan.
“Meet me at 3 pm and I’ll drive you out to lek to show you where it is” he said. “That way you can come back and see the birds displaying in the morning.”
We booked a spot at Doc’s Bed and Breakfast and arrived in the little town of Wray after a two-and-a-half-hour drive from Denver. The country between Denver and Wray was flat and desolate with mile upon mile of winter wheat, rye, and corn crop residual. Near Yuma, we encountered several cattle feedlots where thousands of animals are raised and finished on grain to maximize beef production before slaughter. We had been bitch-slapped by the reality of American animal agriculture. Driving through such homogenized landscapes was a sobering reminder that over 95% of America’s grasslands have been converted to agriculture. This is by far the greatest threat to birds like the Greater Prairie Chicken.
We met Bob, a tall, friendly man with a shiny bald head, near our bed and breakfast in Wray. As we drove to the lek site in his Ford F-150, we quickly realized the man had a wealth of knowledge and experience from a lifetime spent on his 100,000-acre ranch. Bob told us that they do not actively manage for Greater Prairie Chickens, but what has worked for their bottom line also has worked for the birds. In fact, the 10,000+ acres of grassland that have been converted into corn, potato and bean production have provided the birds with such a valuable source of food during the winter that Bob thinks the numbers have actually increased over the last decade.
Meeting Bob in his office near the ranch
After a few sharp turns on a rural county road, we crossed over a cattle guard and drove out through mixed grass prairie – a sea of grass as far as the eye could see. Western wheatgrass (Pascopyrum smithii) and sand bluestem (Andropogon hallii) were dotted with the occasional yucca (Yucca glauca). Ten minutes later, we arrived at a water pump and a fence line. Beyond it, we were greeted by two inquisitive Burrowing Owls.
“This is the first day I’ve seen the owls this year. You’ll be seeing them a lot through here. They’re not too shy.”
Bob pulled the truck up through another cattle guard and circled around to the far corner of the fence line.
“This here’s the lek. Tomorrow morning, they should be right here displaying. There should be a good number of them too. I’ve counted close to forty-five birds here before.”
The road to the lek
The site of the lek was admittedly underwhelming. It was trampled and compacted, littered with cow patties and chunks of chalky earth excavated from the deep burrows the owls were using. I stooped down to pick up a feather.
“Is this from the Chickens?”
Bob nodded and smiled. “You betcha.”
A Greater Prairie Chicken feather inside my Sibley Guide to Bird Life and Behavior book
“So we’re not disturbing anything by walking over this lek right now? Aren’t the birds sensitive to us being here?” asked Angie.
“This is what you call an ancestral lekking site,” Bob explained. “These birds have been coming back to this same spot for hundreds, maybe even thousands of years. I’m convinced that if someone was to pave this over for a Walmart parking lot the birds would continue to use it. When you get here tomorrow, the birds will fly off – they are definitely skittish. But once you settle in, they will come right back and resume their ritual activities. These males are thinking about one thing right now and one thing only.”
A solitary yucca (Yucca glauca) amidst a sea of mixed-perennial grasses
Bob went on to tell us that the mortality of the males was surprisingly high during the breeding season. Apparently, the birds are so concentrated on their strutting and fighting that they don’t notice predators like coyotes and hawks until it’s too late.
“A rancher can always tell who’s done the killing” Bob said. “When we see a pile of feathers, we know it’s a coyote who has grabbed it by the neck and taken it off somewhere to eat it. When you see scraps – like pieces of the beak or bones - you know it was a raptor that pulled it apart right on the site.”
Although Swainson's Hawks (Buteo swainsoni) eat primarily mammals, they are denizens of the open grasslands that will occasionally depredate Greater Prairie Chickens
We made our way back to Wray, passing several horned larks (Eremophila alpestris) and western meadowlarks (Sturnella neglecta) singing contently from fenceposts.
Horned Larks (Eremophila alpestris) were by far the most abundant songbirds we saw on Bob's ranch. Their high-pitched, tinkling songs were heard throughout our time here
Before parting with Bob, he took us over to his office where he had us sign his guestbook. He showed us a collection of dinosaur fossils he and his wife had dug up from his ranch in South Dakota. His prized fossil was a piece of fossilized hadrosaur skin.
Bob showed us one of his prized possessions: fossilized Hadrosaur skin he found on his ranch in South Dakota
Bob showing us his dinosaur fossil collection
In the evening, after a great meal at El Vaquero, a reformed church turned Mexican restaurant, we returned to Doc’s where we enjoyed a few libations with Mike, a fellow guest at the bed and breakfast. Mike had spent his winter in Colorado with his wife Cassie after spending his 20th summer as a boat captain and naturalist in Seward, Alaska. He had also come to see the birds. Kindred souls.
In the morning, Mike met us in the kitchen just before 5 am to travel out to the lek together. Doing our best to remember where to turn, we crossed the cattle guard and set out onto Bob’s ranch as we raced the sun to the horizon.
Approaching the lek, the whooping, whelping, and screeching of the birds was impressionable. By forcing air out of their drum-like neck membranes called tympanums, they produce strange sounds that are not unlike that of someone blowing on top of an empty bottle. Listen to the sounds at the very beginning of this video. Turn up the volume.
Over the course of the next hour and half, we watched the birds strut, display, and fight with each other. Occasionally, females would approach the lek in curiosity, their drab, mottled plumage differing considerably from the male’s. Lekking species often show strong sexual dimorphism and the Greater Prairie chicken is no exception to this rule. The most dominant males in the center of the lek would raise their two ear tufts (pinnae feathers that rise from their yellow ocular combs (eyebrows)), drum their feet, hoot with inflatable pigmented air sacs, and rattle their feathers. Occasionally, they would run from side to side, looking like they were carried by wheels instead of feet. I was most impressed when the males would "flutter jump" into the air and scrapple with each other in the feistiest way possible.
The most dominant males attract the lion’s share of the attention. In some cases, one male can attract 90% of the females on the lek, ensuring that genes from the most fit males prevail. This begs the question, if all of the genes come from a small percentage of males, how is there any genetic variation in the population? This is the crux of the lek paradox, a question that has been posed by many evolutionary biologists. Some biologists have postulated that the well-developed secondary sexual characteristics in males that females look for are the best indicators of individual genetic variance.
As we watched the spectacle unfold, the wind blasted us with unrelenting ferocity. It was as if the wind came directly from the frigid arctic circle, cutting into us at the core of our being. To add insult to injury, the wind whipped sand across our faces and we were met with an unwelcome grit in our teeth. As forgiving as the rolling sea of grassland looked from a distance, it was a harsh, blistering environment from which we were eager to seek shelter.
Trying to bird in an unrelenting wind was not pleasant. We were able to see a Long-billed Curlew and Northern Harrier, both in flight. Here Angie is pictured with Mike (foreground)
The dance of the spring chicken certainly did not disappoint. We felt fortunate to witness this marvel of the natural world right in front of our eyes. To think that just 150 years ago, the skies were clouded with thousands of Prairie Chickens is absolutely mind boggling. In fact, there was an eastern species of the Greater Prairie Chicken known as the Heath Hen that lived in the Pine Barrens of New Jersey up through Massachusetts. It went extinct in 1932.
We now have reduced this quintessential grassland species to small corners of its original habitat. It is sad that we have to go to such lengths to see it. I hope that one day, this denizen of the Great Plains can return to restored landscapes where other human beings can have the unique American experience of watching it display in the same way it has for ages.