GLYNDON, Minn. - The lights of a city 15 miles away are still glowing on the horizon when rustling is heard in the prairie grass. Soon darkness will give way to a spectacular show.

It's the annual mating ritual of the prairie chickens, who gather on this man-made breeding stage east of Fargo, N.D., every spring. The area is known as a booming ground, named for the bassoon-like sounds played by the male birds.

Brian Winter, who helps manage the area for a nonprofit conservation group, marvels at the site while protected by a plywood chicken blind.

"When I'm sitting here I'm always struck by the fact we can see this growing metropolis just 15 miles away," whispers Winter, referring to the Fargo and Moorhead, Minn., area. "Yet we have these birds that are protected because of the habitat."

Winter, the regional program director for the Nature Conservancy, is offering a history of the booming grounds when he is interrupted by a whoop, then a cackle. The male birds are warming up. They're waiting for enough light to begin showing off for the hens.

Some male birds can be seen popping their heads out of the grass, even though the sun has yet to show.

"I'm sure this is where the saying 'you have to get up with the chickens' comes from," Winter said, chuckling. "You can't even see them and they're trying to find a mate."

It's a free-for-all when the sun comes up, with the male chickens defending their territory. When other males invade, there's usually a chase and occasionally a fight. When hens saunter by, the males puff out their orange pouches, rise on their toes and strut their stuff.

The male birds also like to flap their wings and leap off the ground.

"That's called a flutter jump. They're hoping the females will see them and go over there," Winter said. "Their whole point right now is, 'Hey, look at me, I'm the coolest guy out here.'"

This particular booming ground, known as Bluestem Prairie, covers about 2,900 acres in far western Minnesota. It used to be a gravel pit, to accommodate construction in the area.

The Nature Conservancy turned it into a booming ground in 1990, after clearing rocks and planting native prairie grass. The group either burns or hays the field every year.

"This is the most active and dominant booming ground in the area," Winter said. "Most years there are 30 to 50 males thumping on this spot, so it can really get booming."

Although the future of the prairie chicken was uncertain at one time, the restoration of grasslands has helped increase the population, Winter said.

The bird almost was nonexistent in North Dakota 25 years ago, said Jerry Kobriger, an upland game management supervisor for the North Dakota Game and Fish Department.

"At this point we're not doing too bad," Kobriger said. "I think a lot of it is going to depend on what happens with the habitat and CRP (the federal Conservation Reserve Program)."

In the meantime, Minnesota and North Dakota have started limited hunting seasons for prairie chickens.

"There's a lot of history and tradition with these birds," Kobriger said. "You hear stories about trainloads of birds going back east that they shot to serve in restaurants.

"Today, there aren't a lot of people who recall those things," he said.

The average life span of a prairie chicken is about two years, Winter said, although the bird could likely live up to 10 years in captivity.

"There are a lot of things out there that want to have lunch with these guys," Winter said.

Other hazards include snowstorms, power lines and vehicles.

Winter said prairie chickens are considered the mascots of tall-grass birds, attracting people from every state and Canada. Many days, both chicken blinds are booked.

"We get a lot of value out of the prairie chickens," Winter said. "They're comical, they put on a good show. It can be cold and windy and rainy and their going to be out there each morning in April and May doing their thing."