Spring is well-known to be the season of breeding, especially for birds. Grouse, however, take it to another level.
One thing that makes grouse breeding strategies unique is the use of a lek. A lek is defined by Merriam-Webster as “an assembly area where animals gather for competitive courtship displays.” Male grouse use these leks to attract females, usually in the early morning and evenings of early spring. Biologists use these leks as a convenient way to count birds.
Mountain grouse males, such as the dusky grouse, ruffed grouse and spruce grouse, perform their breeding displays in forested areas, usually on their own or in small groups, and aren’t really “leks” per se. Biologists can do general counts for these birds, listening at certain distance increments for evidence of a display taking place.
For prairie grouse like sharptails and sage-grouse, on the other hand, the lek display and area is more of a region-wide social event. Prairie grouse leks are large, accommodating dozens of birds, and are often found on fairly flat, elevated areas with sparse vegetation, allowing biologists to observe numbers from afar without disturbing the dance.
This prairie lek site gives eager males a proper stage to strut their stuff, display, make noise and occasionally “fight” to try and impress the females, who are the ones that do the choosing. Statistics show that a very small percentage of the males mate with the majority of the females.
The displays are different depending upon the species. Male sharptailed grouse are very active – think a rave-type club – where they stomp their feet up to 40 times per second with tails erect looking like little wind-up toys, inflate colorful neck sacs and make many different sounds to show their worth.
Male sage-grouse are more subtle – think a jazz lounge – where they perform a booming “wet-blurp” sound and showcase a prominent air sac and colorful feather display, mostly by puffing up their chest and strutting around with their tail feathers fanned out.
Birds return to lekking grounds, for the most part, year after year and sometimes for decades. Occasionally, birds will abandon a lek, especially if populations become low or if there are constant disturbances or threats. However, as things change over years, old leks will become active again.
FWP staff, other land agencies and some volunteers stay busy every spring counting prairie birds in the early morning hours on specific long-studied leks, while keeping their eyes and ears out for new or yet undiscovered leks. These efforts give biologists a general idea of population trends from year to year.
Keep in mind, however, that although the number of birds on the lek is important for estimating current populations, even more important for upland bird season forecasts are the success of nesting, chick-rearing and brood survival throughout the spring and summer.
All birds seen on spring leks are at least 1 year old and considered adults. During hunting season, juvenile birds are more frequently harvested than adults, so a good bird season really depends on good brood survival AFTER the lek.
If you ever get a chance to observe a lek, arrive at least 45 minutes before sunrise, be a good distance away and remain in your vehicle if possible, stay quiet and avoid disrupting the lek at all costs. If the party gets busted, it could significantly set back breeding opportunity.
Source: Montana FWP press release
Photo: Megan Strickland Sacry, 2017