Trained observers across Wyoming counted an average of 21% fewer male sage grouse on breeding-ground leks in 2019 compared to 2018, the state’s sage grouse biologist said Wednesday, an expected decline that continues a three-year trend.
This year’s count of strutting males marks a 44% slide from a most-recent high in 2016, according to calculations made by WyoFile from Game and Fish figures. There was an average of 35.6 males per lek in 2016 compared to 20.1 in 2019, Game and Fish reported Wednesday.
Wyoming’s numbers reflect other states’ declines, Wyoming Game and Fish Department Sage Grouse and Sagebrush Biologist Leslie Schreiber said. Recent studies show greater sage grouse populations rise and fall in 6- to 8-year cycles, she said. Those cycles are believed to result from weather and climate’s influence on food and cover.
“Sage grouse across the West follow synchronous trends,” she said.
Idaho, Nevada and Oregon wildlife officials have also reported a third straight year of plummeting population estimates. Those 2019 estimates and counts are down 52%, 33% and 38% respectively from 2016, according to officials’ figures and WyoFile calculations.
Those three states collectively hold about 42% of the world’s sage grouse population. Wyoming is home to about 37%. Worries about a West-wide downward trend appear to have been proven to a large degree with states holding 79% of the population now reporting.
2019 count not ‘a bad number’
Despite the statistics, “I don’t see 2019 as a bad number,” Schreiber said in a telephone interview.
“This year’s lek counts were within the range of variability that we’ve seen over the last 20 years,” Schreiber said. Worries grow among scientists “if the [population] peaks get lower or the troughs get lower,” she said.
The 2019 Wyoming count is 47% above the all-time low in 1996 and 18% above the most recent low observed in 2013, she wrote in an email. Lek counts in 2019 were 22% lower than the 10-year average between 2009 and 2018, she wrote.
In May Wyoming’s former sage grouse leader Tom Christiansen expressed worries that a “dark cloud” was hanging over sage grouse populations across the West. Observers’ reports from Wyoming and elsewhere suggested this year’s spring counts would be down, he told the state’s Sage Grouse Implementation Team.
Even last fall, predictions for a decline were in the wind.
“We were expecting lower lek counts for 2019 after 2018’s poor production of juveniles,” Schreiber said. Wyoming biologists estimated that ratio at 0.8 chicks per hen, based on a voluntary survey of hunters.
Across sage grouse country in Wyoming, Game and Fish routinely mounts barrels on posts and asks successful sage grouse hunters to deposit one wing from each bird taken. By examining the samples, biologists each November establish the ratio of chicks to hens.
“To have a stable population we think we need 1.2 to 1.5 chicks per hen,” Schreiber said. To increase the population, the ratio needs to be higher than 1.5 to one.
The apparent West-wide decline indicates that the diminishment in numbers is not solely an Equality State issue.
“I guess it’s important [to understand] these trends don’t just happen in Wyoming,” Schreiber said. “Sage grouse across the West follow synchronous trends.”
Wyoming’s count of strutting males hit a nadir in 1996 with an average of 12.5 males per lek, Schreiber said. That followed extended drought that was coupled with “ineffective habitat protection,” Schreiber said.
“That’s kind of the reason for all the sage grouse work that’s happened since then,” she said.
Conservationists and wildlife managers, including at the federal level, took notice. In 1999 the Northwest Ecosystem Alliance and Biodiversity Legal Foundation petitioned the U.S. Fish and Wildlife Service for the Washington population to be protected under the federal Endangered Species Act.
Other petitions followed, prompting Wyoming’s then-Gov. Dave Freudenthal to act to avoid federal Endangered Species Act listing. In 2008 he issued the first Wyoming gubernatorial greater sage grouse executive order directing state agencies to limit development in mapped core habitat, among other things.
Freudenthal’s successor Gov. Matt Mead updated and issued his own executive order and Gov. Mark Gordon followed suit last week. For the first time, the Wyoming order includes requirements to collect data on the progress, or lack thereof, of sage grouse conservation measures.
That’s “entirely 100% brand new with Gov. Gordon,” Schreiber said of the reporting requirements.
“Hopefully we can start evaluating the effectiveness of our actions since 2008,” she said. “It’s a very complex system and it’s going to take a lot of bright minds to answer the question — how effective are we at conserving habit and understanding that in the context of ups and downs that sage grouse experience.
“I’m encouraged that we have [the tool] to try to help us learn that,” she said.
Trained observers counted more than 21,000 male sage grouse on 87% of known occupied leks in Wyoming during the spring census, Schreiber said. Federal Bureau of Land Management workers, Wyoming Game and Fish personnel, U.S. Forest Service employees and volunteers ventured to the strutting grounds before dawn to count the birds before they dispersed shortly after sunrise.
Schreiber agreed this year’s numbers come with “a wee bit of a question mark,” because of seasonal blizzards across the region. That delayed counters getting to some leks.
Nevertheless, 87% coverage of known occupied leks in Wyoming is close to the average access over the last five years, which has ranged between 88% and 90%.
“I don’t think [counts] would change if we had better access, but it’s something I monitor,” Schreiber said.
Now she’s waiting for November’s chick/hen ratio, which ‘I’m very interested to see,” she said. “It’s a precursor of lek counts to come.”