Karl Puckett

kpuckett@greatfallstribune.com

A strange drumming sound filled the pre-dawn dark on the rolling prairie at Benton Lake National Wildlife Refuge 10 miles north of Great Falls on Tuesday.

It was coming from one of northcentral Montana’s largest sharp-tailed grouse leks.

Geese, swans descend on Montana’s Freezout Lake

That’s a flat spot where males gather and rapidly stomp their feet and rattle their feathers as part of a ritualized courtship dance that occurs at the same location each spring.

For the male grouse, it’s an intense battle for the opportunity to mate with hens, and just a few of them will win.

“If it were a hill, it would be king of the hill,” said Bob Jordan, a biological technician at the refuge.

The dance show is also entertaining to watch, and more visitors are applying for the chance to witness it from a seat in the “grouse house,” an 8-by-12-foot wooden blind giving them a front-row seat to one of the most unusual courting rituals on the prairie.

Visitors are so close to the action that no spotting scope is required, with the birds, running on hormones, oblivious to the voyeurs.

“It’s unlike just about any other courtship routine you can think of,” Jordan said.

Sharp-tailed grouse leks can be found across the mixed-grass prairie of northcentral Montana, said Bob Johnson, deputy manager of the refuge.

But the grouse house is the only place that he knows of in the region where bird watchers can sit on folding chairs sipping coffee while clandestinely viewing the dancing fools, if they’re willing to arrive before dawn and have a reservation.

The blind has been in place since 1990.

But interest has grown so much the U.S. Fish and Wildlife Service was forced to implement a lottery system a few years ago to choose who gets to use the hut, and the dancing show is booked for the year. Six seats are available in the blind on weekends in April and May.

Lion makes epic trip from Canada to Montana

“It’s very popular,” Jordan said.

Winners of the grouse house lottery are treated to a prairie peep show.

From a distance of just a few feet, visitors peer out of six windows in the blind spying on males who dance exotically.

They stomp their feet like jackhammers, up to 20 times a second, and turn in a circle. With their heads held low, they cock their tail feathers and sprint across the lek with their wings spread wide, looking like little fighter jets.

“They’re showing off,” Jordan said.

The foot-stomping and feather rattling creates the drumming that also sounds a bit like cards snapping on bike spokes, or a machine gun, or a running motor or any number of sounds that are similar but don’t quite capture it.

“They’re noisy,” Jordan said.

They also inflate and deflate purple air sacs on their necks creating an occasional boom.

Only the males dance in the communal breeding ground, and the dancing and vocalizing are a broadcast to females that they’re the best males out there.

Dominant males control the center, and less dominant males try to butt in, with beak-to-beak face-offs occurring between two and sometimes three birds.

Predatory golden eagles are killing sage grouse

A deep pigeon-like cooing, a cross between a gobble and gurgle, is another sound on the grouse lek, along with higher-pitched whistles.

Only a few males on a given lek will win the majority of matings, which drives the intensity of the moves and calls and also leads to continual fighting, according to Cornell Lab of Ornithology.

Birds mate in the vicinity of the dancing grounds after which hens move to thicker grass cover to nest and typically lay about a dozen eggs.

At 6:45 a.m., as the sun began to rise, turning the sky pink, dozens of the tiny dancers, who already were performing, gradually became visible.

As the morning progressed, the grouse would freeze in unison and end their vocalizing, with the lek silent except for song birds, before starting up again.

“It seems like it’s a very unique dance routine in that it’s actually synchronized,” Jordan said.

The lek was documented in 1988 with 12 males. It’s been in use ever since.

Today, it’s not uncommon to find up to 75 birds, and most are males.

Visitors are asked to count the number of males they see on the lek each year.

“It gives you an index if they’re doing good or bad,” Johnson said.

The population on the refuge has been growing the past five years, Jordan said.

It’s led to three smaller spin-off leks that total another 75 birds, but the public viewing blind is at the main lek only.

Sharp-tailed grouse are fairing better than their cousin, the sage grouse, which has been the object of new protections by federal and state agencies to protect declines in populations over the years, Jordan said.

But the loss of native habitat is a concern for sharp-tailed grouse as well, Jordan said. The state of Montana lists populations west of the Continental Divide as a Species of Concern, but not populations east of the Continental Divide where Benton Lake is located.

Grouse begin showing up in the leks in late February and remain until mid-May. The flat area where they gather allows them to see a long ways and keep an eye on predators, which include coyotes and hawks, Jordan said.

“We do have a decent amount of undisturbed native prairie here,” Jordan said.

During the rest of the year, the birds scatter and spend more time in shelter belts with trees.

Visitors are asked to arrive an hour before sunrise. It was 33 degrees Tuesday when the clucking, booming and drumming could be heard in the dark as visitors who, guided by a flashlight, set off across the prairie toward the grouse house.

At 7:19, a coyote barked. At 7:21, a buck antelope trotted across the prairie behind the lek. In the visitor’s log, it was reported that two hawks were seen flying over the lek earlier in the month.

The peak of dancing occurred just before dawn to about 30 minutes after the sunrise, but 50 to 60 birds, most of them males, were active for a couple of hours.

Follow Karl Puckett on Twitter @GFTrib_KPuckett.