Grizzly bear deaths in the Greater Yellowstone Ecosystem continue to climb into record territory with 2018 on track to become the deadliest year for bears since they were listed as threatened in 1975.
Through Tuesday, 42 dead Yellowstone-area grizzlies were listed in a mortality database maintained by the federal Interagency Grizzly Bear Study Team. Even factoring out five grizzlies that are thought to have died last year or before but just turned up recently, the 37 mortalities tallied through Sept. 6 easily outpace the death rate from 2015 through 2017 — which, until now, were the deadliest years in modern history.
The rate of grizzly deaths being observed over the past four years is among the arguments environmental attorneys are using to persuade a federal judge to reinstate Endangered Species Act protections for the estimated 700 to 1,000 grizzly bears that roam the Yellowstone region. Grizzlies switching to a more meat-based diet — which brings them into conflict with humans — is causing the higher death rate, the contention goes.
“The big jump came in 2015, but since 2015 every year we’ve been seeing this new, higher level of mortality,” Earthjustice attorney Tim Preso told the News&Guide in August. “The Fish and Wildlife Service has never grappled with the question of, ‘What is the impact of that mortality?’”
“Basically, the bears have found something else to eat, but it’s killing them in record numbers,” he said. “Is that the time to pull the rug out from under the population, in terms of withdrawing the Endangered Species Act designation?”
Preso is representing the Northern Cheyenne Tribe, the Sierra Club, the Center for Biological Diversity and the National Parks Conservation Association in one of six lawsuits that U.S. District Court Judge Dana Christensen is deliberating. On Aug. 30 Christensen heard arguments from the litigants, federal and state managers and their intervenors. In the hours after that Missoula, Montana, hearing he issued a 14-day restraining order that blocked Wyoming’s hunt, set to begin just two days later. A ruling about whether the feds or states ought to be managing grizzlies is expected any day.
In the 12 days that followed Christensen’s order, eight dead grizzlies have been found. Four of the deaths occurred in an area in which grizzlies are carefully monitored and their population is estimated annually, while the other four mortalities were outside the area, where grizzlies are forging new range into more developed territory.
The distinction of where grizzly deaths are occurring — inside or outside the monitoring area — is an important one, Interagency Grizzly Bear Study Team leader Frank van Manen said in an email.
“We are starting to see a trend of increasing proportion of mortalities outside the [monitoring area],” van Manen said. “As grizzly bear population growth and expansion continues in these more human-dominated areas ... the challenges of managing conflicts become more and more apparent. These conflicts disproportionately involve male bears.”
Sort through the data, van Manen said, and it’s apparent that only 25 of the 37 grizzly deaths so far in 2018 occurred in the monitoring area. That compares with 21 deaths inside the same area at the same time last year. Twenty-one dead grizzlies inside the monitoring area through the second week of September is incidentally also the same number that was observed in both 2016 and 2015, according to the study team’s database. That means that an apples-to-apples comparison of this year’s death rate to the past record years puts 2018 out on top.
Dan Thompson, the carnivore chief for the Wyoming Game and Fish Department, was unavailable for an interview Tuesday.
The high rate of death observed is occurring ahead of the brunt of the big game hunting season, historically the deadliest time of year for bears because of self-defense and mistaken-ID shootings. An average of 10 grizzlies are shot and killed annually in the Yellowstone region during run-ins with hunters, according to a News&Guide investigation.