Sage grouse predator research continues across Wyo by ADMB, local groups
Sage grouse researchers across Wyoming have continued to analyze the impacts of predators on sage grouse.
“Through the Animal Damage Management Board (ADMB), we get research requests,” says ADMB Predator Management Coordinator Kent Drake. “The biggest issue we have is predation research for sage grouse.”
Not only is research on sage grouse predators important, Drake mentions that credible, peer-reviewed research is imperative.
“Most of the research has been handled by local predator districts of the ADMB,” he says. “However, the research isn’t viewed as credible.”
Regardless, Drake says it provides interesting insights for future research.
As a result, a handful of research projects are being conducted across Wyoming to look at predators affecting sage grouse.
One long-term project Drake details is a project looking at activity from trail cameras utilizing artificial sage grouse eggs.
“Last year was the seventh straight year that this project was done,” he comments. “It used artificial eggs that were put in nesting sites. Trail cameras were also put on the sites.”
The study used 10 cameras in 2012, each of which was stationed at a nesting spot for one week and then rotated. Data was gathered from 40 nesting sites and showed a variety of predators visiting nests.
“In 2012, 27 of the 40 nests were raided by something or other,” he explains. “The most common visitor was raven.”
Data showed that ravens damaged 24 nests, magpies damaged two, coyotes damaged two sites, skunks damaged three and unverified visitors, according to the study, disturbed two sites.
“It gives us an idea of the damage that a predator can do on nesting sites,” Drake says.
“For the eggs, avian predators seem to be the biggest problem,” Drake adds, “but after they hatch, the sage grouse chicks are more predated on by coyotes.”
A doctoral candidate at the University of Utah is conducting another study funded by ADMB.
“Jonathan Dinkins is using an avicide to control Corvus species,” Drake says, noting that Corvus species include both crows and ravens. “The product he is using, DRC-1339, is licensed in Wyoming and in the U.S., but the only people who can use it are USDA Animal Plant and Health Inspection Service Wildlife Services employees.”
The avicide is available for use to control for livestock depredation or human health and safety concerns.
“The product is usually put in dog food, and it is specific to Corvus, so it has no residual effects,” Drake explains. “It is a very good product for this specific use.”
The study identified depredation areas and counted sage grouse chicks and eggs that hatched after Wildlife Services utilized the avicide to eliminate ravens.
“Dinkins says in his dissertation that there was still sage grouse loss of eggs and chicks, and there wasn’t any significant change in predator losses, even after they lowered raven numbers,” Drake says. “However, they also found that sage grouse seek out nesting in areas where avian predators are not present, when possible.”
Nesting site locations were identified as those areas where fewer avian predators are available, including in areas of rough terrain.
However, DRC-1339 isn’t consistently used in one area from year to year, making repeatability of the study difficult.
Additionally, the use of DRC-1339 is regulated strictly by Wildlife Services, with limits on the use of the product enforced.
Wyoming Game and Fish Department (WGFD) recognized the detriment that ravens were having on not only sage grouse but other industries, as well.
“WGFD recognized the significance of raven populations on sage grouse,” Drake says. “There are a lot of people in southwest Wyoming who are concerned about how many ravens there are, the impact on sage grouse and livestock and the potential detriment they could have on the trona mines.”
Because trona mines produce food grade materials, they risk being closed if ravens contaminate the products.
“WGFD asked for broader control efforts for the benefit of sage grouse,” he says. “They said, ‘We want to be allowed to control ravens for the benefit of threatened and endangered wildlife species,’ and the U.S. Fish and Wildlife Service (FWS) agreed.”
Utilizing avicide, WGFD baited landfills in Rock Springs, Kemmerer, Riverton and Pinedale, resulting in an estimated 31 percent of the population controlled.
“They are going to work the landfills again this spring,” Drake notes. “It will be interesting to see how effective the project is.”
“Certainly predation is not the whole answer to sage grouse survival,” Drake says, “but it deserves credit as part of the problem.”
Drake addressed attendees of the 2014 WESTI Ag Days at the beginning of February.