CASPER — Sage grouse reproduction numbers remained stable last year, according to initial data collected by Wyoming Game and Fish Department.
State biologists closely monitor Wyoming’s iconic bird every year to ensure the population count stays at healthy levels. The department compiles the reproduction numbers each spring by counting chick and hen feathers left by hunters over several months in collection boxes.
Sage grouse numbers have reached high enough levels to allow limited hunting of the bird. “Hunting is an important component of sage grouse management in Wyoming and has not shown to have a negative impact on the population,” Schreiber said. “We appreciate hunters dropping off wings for our data collection.”
In this round of collection, hunters harvested a total of 980 chicks and 874 hens feathers. That makes the state’s chick-to-hen ratio 1-to-1, in line with 2019 ratio numbers.
“It appears Wyoming’s sage grouse populations are flattening out at the trough of the cycle,” Leslie Schreiber, a sage grouse biologist, said in a written statement. “A growing population needs at least 1.5 chicks/hen.”
By “trough,” Schreiber is referring to the pattern seen when the numbers are plotted on a graph: The line graph will start to take the shape of undulating hills — rising up, holding steady and then dropping again, on a six- to eight-year cycle. The trough is the period between peaks when the numbers level out.
The Game and Fish Department has about six decades’ worth of data on the bird. But the reasons behind these wide fluctuations in lek counts remain unclear, even for scientists. Some have found signs that it’s linked to changes in habitat, food or weather.
State biologists also use data on leks to determine the health of sage grouse populations. Leks are the breeding grounds where sage grouse faithfully flock each year. About 1,800 known, occupied leks exist in the state.
The sage grouse lek average attendance numbers will come out this summer. But initial counts this year of male lek attendance “barely budged,” according to the state biologist, down about 1.5% compared to spring of 2020.
When spring arrives, sage grouse begin their elaborate mating ritual. Schreiber and her team of trained observers will hit the road to count as many birds as they can find at dawn. Though numbers only paint part of the picture, data on sage grouse matters. It informs the state’s conservation strategies and figures into debate when officials wrestle with how to balance both economic development and preservation of the bird.
Wyoming is home to more sage grouse than anywhere else in the world — about 38% of the global population.
About three decades ago, sage grouse population numbers dropped to the lowest levels ever recorded in Wyoming, likely attributable to habitat destruction and drought. Though sage grouse numbers have rebounded, threats to the population still persist.
“Sage grouse are a sagebrush obligate species and could not survive without it,” Schreiber said.
The sensitive birds are particularly vulnerable to human disturbances and loss of suitable habitat.
Wyoming conservationists, industry groups and political leaders have gone to great lengths to establish a state-led adaptive management plan. The goal is to not have sage grouse listed as endangered under the Endangered Species Act. A big part of that has been safeguarding “core” areas, or habitat where a lot of sage grouse live. That means prioritizing conservation and instituting restrictions on development in these areas.
In early 2020, Gov. Mark Gordon issued an updated executive order on the state’s plan to manage sage grouse populations.
The order upheld existing conservation strategies instituted in 2015 but also added new data collection requirements and outlined guidelines for reclaiming disturbed sage grouse habitat.
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