Through the dim, early morning light and the sea of tall grass, their shapes can't quite be made out in the distance yet. But scanning the prairie with a pair of binoculars, supervisory fish and wildlife biologist Shawn Stratton affirms he's found what he's looking for by the unmistakable sound - prairie chickens.
From late March through April, the greater prairie chicken certainly isn't shy about vocalizing its presence. This time frame is known as booming season - named for the noise the males make by inflating the air sacs in their throats - and is the time when prairie chickens take part in an intricate mating ritual.
"The males will get up on the lek, which is their territorial mating grounds basically," Stratton said. "And they entice the females to come into the leks, or they're also called booming grounds, and they do a dance and use their air sacks to make a booming sound and they do a little ritual dance."
Stratton explained that although this particular ritual is unique to the greater prairie chicken, each of the grouse species does a variation of booming in their own way.
"Sage grouse use a little bit of a different display, but all the different types of grouse species around the world do similar things during mating season," he said.
Apart from their distinctive calls and fancy footwork, what's all the fuss about the greater prairie chicken? By monitoring prairie chicken populations, conservationists can get a pretty good idea of how tallgrass prairie ecosystems are faring overall.
"The prairie chicken is a keystone species that can indicate the health of the other grassland species on the prairie," Stratton said. "So, if you're seeing any type of declines or changes in (prairie chicken) population numbers, it's probably going to be a good indication of what's happening with your other species that depend on the grasslands as well."
Stratton said a lot of different types of grassland bird species, as well as other grassland dependent species like the regal fritillary and monarch butterflies, rely on the grasslands.
"A lot of those species depend on the grasslands," he said. "So for Fort Riley conservation, we want to keep an eye on the populations and have a good idea of what's happening with their numbers and the habitat that they're using. That's why we do the surveys and look at them in the detail that we do."
In past years, the lesser prairie chicken, a relative of the greater prairie chicken, was listed as a threatened species and is currently being looked at by the U. S. Fish and Wildlife Service to potentially be added back again, explained Stratton. Knowing there is also interest nation-wide in listing other grouse species in decline and knowing the listing of the greater prairie chicken could hinder military activities on Fort Riley, the fort is keeping close watch on their prairie chickens.
To help them, the Fort Riley conservation team had partnered with Kansas State University Cooperative Fish and Wildlife Research Unit for a new study that began in January and is projected to run through a few seasons.
The project is titled, "Response of Greater Prairie-Chickens to Natural and Anthropogenic Disturbance on Fort Riley," and notes that while greater prairie chickens once resided in abundance throughout much on the Midwest, their numbers have been in gradual decline, resulting in greatly diminished range compared to their historic habitat.
According to the project proposal, cause for population declines include a number of factors, ranging from conversion of native prairie for development and crop production to inappropriate timing and intensity of livestock grazing, construction of roads, utility corridors, fences, towers, turbines, and energy developments, introduction and expansion of noxious weeds, alteration of fire regimes, climate change and planting of trees.
While total numbers nation-wide and in the greater Flint Hills may be on the decline, Stratton said populations on Fort Riley have been relatively stable throughout the years.
"We've got survey data that dates back into the '70s for the greater prairie chicken," Stratton said. "So it's a long term data set. We have a good idea of what's going on with the population on post."
The new study will only help add to that knowledge by seeking to answer the question of why the birds seem to be faring better on post then their neighbors living in the surrounding areas.
A two-year project, the study will focus on trapping and - for the first time - using GPS tracking collars on hens to gain a better understanding of what the birds are doing on the installation.
"The focus is to collar some of the hens and see what habitat they're using during nesting season and all the seasons actually," Stratton said. "With the GPS collars they will be affixed with, we will be able to download the specific locations they are utilizing and to follow up with successful hatches that they have following the broods' use of certain types of habitat. That will help us with how we do everything; from how we do prescribed fire, to some of our agricultural outlease programs and how we implement other management programs like spraying for noxious weeds, and potentially how we use food plots on the installation."
Some of the objectives of the study include determining annual lek locations, monitoring the impacts of disturbances such as prescribed and wild fire, military training activities, haying and estimating movements and ranges through the use of the GPS tracking collars. Overall, the Fort Riley conservation team knows that looking at how the birds are using the installation now will help with management decisions in the future.
"It's a big project for us," Stratton said. "We want to make sure we have a thorough understanding of how to keep our species in good shape on the installation so that we can make the best management decisions we can and to allow the military to train on the installation without restrictions"