Concerns are being raised that the endangered sage grouse could disappear from Canada after a dramatic drop in its population was noticed this spring.

The Alberta Wilderness Association says only 18 male birds have been counted in Saskatchewan — less than half of the 42 recorded in the last count in 2010.

In Alberta, only 13 males have been counted, which is the same number recorded last year.

The count was done in the spring when the distinctive prairie bird mates.

"Every year, the sage grouse males go out to the leks, which are their mating grounds, to do these display dances, this extravagant dance, and try and attract the female hens. So, that's when the most accurate counts can be made," said association conservation specialist Madeline Wilson.

"There's a huge decline in Saskatchewan, which is a significant concern to us."

Wilson said the number of males left in Alberta is "hugely concerning."

"Pretty much they're on their way out," she added.

Habitat shrinking

A male sage grouse can weigh up to 3.6 kilograms, and the female can grow to about half that size. The male has a yellowish neck sac for elaborate courtship displays. The bird inflates the sac, puffs out its chest and struts and dances to attract females.

Wilson said the problem is that the sage grouse habitat is shrinking in southeastern Alberta and southwestern Saskatchewan.

"Sometimes, they'll travel between the two provinces ... so it's extremely important to maintain that connectivity," she said.

"When you see that the population is shrinking on both sides of the border, it just shows the range is decreasing, and the good habitat and the population will become more and more vulnerable."

The wilderness association says research has shown that when oil and gas development encroaches on sage-grouse habitat, the birds abandon their leks and other habitats crucial to their survival.

The sage grouse used to be in British Columbia but is now considered extirpated there.

It has been listed as endangered since 1998, and scientists estimate there are fewer than 100 birds left in Canada.

Environmental groups launched court action against the federal government earlier this year, demanding an emergency protection order for the birds.