'An avian mosh-pit': Mating habits of the sharp-tailed grouse explained

It took careful planning and 5 a.m. wake-up calls, but naturalist Brian Keating managed to catch the mating dance of some Alberta sharp-tailed grouse that he described as "an avian mosh-pit."

There are about 25 species of grouse, and the sharp-tailed grouse is one of the smallest — according to Keating, they're roughly the size of a chicken.

In Alberta, they are usually associated with the province's open grasslands or cultivated areas, but can also be found in aspen woodlands.

Last week, on a friend's ranch just south of Pincher Creek, Keating and his wife, Dee, trekked through the night, and at dawn from inside a trailer managed to observe male grouse performing a mating ritual that was "astoundingly fascinating mayhem."

"They were gathered at a dance location, which is called a lek, and I guess a lek would be best described as a polygamist mating arena," Keating told the Monday edition of The Homestretch.

"It's a place where the males come and dance, and they show off for the females."

Incredible display

Leks are frequented by grouse for decades, Keating said — the grass is typically flattened.

The sites grouse use are often chosen for good visibility, so that predators and arriving female grouse can be scouted.

And the elaborate courtship display produces the greatest activity at dawn, when about a dozen male grouse begin stamping their feet at a rate of 20 times per second while rattling their tails back and forth.

The sound of their feet is accompanied by the grouse's own call, made with the inflation of purple sacks on the sides of their necks.

And years ago, when Keating worked at the Calgary Zoo, that sound was loud enough to reverberate across Zoo Island.

"They make a booming sound with it," Keating said. "They do this incredible display with their wings out."

'Really quite special'

Females come in and survey the dancing males, and presumably choose the one with the best moves, Keating said.

And another factor that contributes to who gets picked as a mate is the location within the lek.

"Location … allows for 80 per cent of the mating to occur by 10 per cent of the males," Keating said.

"I guess to hold location, you have got to be an exceptionally vigorous and experienced male. And obviously, that's the male that the females want, to have access to his genes."

Watching from the inside of their trailer, and with the windows closed so as not to disturb the grouse, Keating said they watched the males step up their dance moves as females approached, before some flew off together. 

And the whole display, he said, was "absolutely amazing."

"It was really quite special," Keating said.

For more fascinating stories about Alberta's wildlife from naturalist Brian Keating, visit his website and check out these stories:

With files from The Homestretch.