Greater sage-grouse chicks are struggling to survive drought conditions, Wyoming Game and Fish Department data shows.
Annual counts of male sage-grouse in northeast Wyoming’s Powder River Basin show a decline from an average of 15.3 male sage-grouse per lek last year to 13.6 this year. Populations are cyclical, so the decline locally and statewide is not surprising, officials say, but drought conditions are having an adverse effect on the youngest birds.
“Habitat projects that keep water on the landscape are a priority,” said Leslie Schreiber, sage-grouse and sagebrush biologist with Game and Fish. “During dry conditions, and especially this year during the drought, it’s very tough on sage-grouse chicks that rely on wild flowers and insects during the first weeks of life.”
This year, according to a press release from Game and Fish, sage-grouse broods averaged 1.1 surviving chicks per hen in Wyoming. The average needs to be closer to 1.5 chicks per hen for the population to grow. According to the U.S. Department of Agriculture Natural Resources Conservation Service, a sage-grouse hen lays, on average, seven to nine eggs.
Drought not only increases wildfire risk — another danger to sage-grouse populations — but dryness also wipes out sage-grouse chicks’ resources. Chicks do not eat sagebrush, the preferred diet of adult sage-grouse, until they’re at least 4 weeks old, according to the Utah State University extension office.
“When it’s dry, you have high chick mortality due to the lack of food and cover,” Schreiber said. “They don’t have food to eat, and they don’t have sufficient vegetation to provide them cover.”
Johnson County has been experiencing severe to extreme drought conditions since spring, according to the U.S. Drought Monitor. Conditions were the same in the second half of 2020 and in the spring, when officials completed sage-grouse lek counts.
Maps from the National Weather Service’s Climate Prediction Center, which provides a U.S. seasonal drought outlook, show that drought is expected to persist through the end of 2021 in Wyoming and much of the rest of the High Plains.
Jim Fahey, Natural Resources Conservation Service hydrologist, said drought conditions have persisted this year due to a dry spring and June. At this point, it’s difficult to determine whether dryness will continue into next year, he said.
“Most of Wyoming, we’re reliant on spring precipitation. I don’t see drought conditions changing until we know what’s going to happen next spring,” Fahey said. “It’s going to stay unless we have a really wet October. We’ve had them in the past, but we are so low in precipitation in parts of northeast Wyoming that it’s going to take a really wet October.”
Similarly, Schreiber said, it is too early to determine whether this downward trend in lek counts is worrisome. Still, it is apparent that drought conditions and warm temperatures that have characterized this year have been an issue, and it is one that sage-grouse managers plan to address. Moving forward, maintaining moisture on sage-grouse habitat will be a priority.
“I’m talking about creating these riparian areas, these green zones where instead of just dried-out dirt, you keep water there and raise that water table. You can have little oases, these riparian areas where we can provide good cover and keep those sage-grouse chicks happy and healthy until they start eating sagebrush 100% of the time,” she said.