A federal judge has granted a temporary restraining order stopping grizzly bear hunts in Wyoming and Idaho/NPS

Grizzly bears that roam the Greater Yellowstone Ecosystem, a sprawling 34,000-square-mile landscape of national parks, national forests, wildlife refuges, and state and private lands, gained a reprieve from hunting seasons that were to open in Wyoming and Idaho on Saturday when a federal judge granted a temporary restraining order halting the hunts.

U.S. District Judge Dana L. Christensen granted the TRO on Thursday, noting that "once a member of an endangered species has been injured, the task of preserving that species becomes all the more difficult.”

Interior Secretary Ryan Zinke and the Trump administration stripped Endangered Species Act protection from grizzlies that roam in and out of Yellowstone and Grand Teton national parks back in June 2017. That move paved the way for the grizzly hunts in Wyoming and Idaho. More than 20 grizzlies could be shot and killed, including as many as 13 females, under the proposals.

This is just the latest battle in a long-running tussle over the fate of the iconic bears.

Legal challenges have taken issue with the Fish and Wildlife Service’s evaluation of the mortality consequences of the bears’ recent shift to a more heavily meat-based diet following the loss of other foods, such as army cutworm moths and Yellowstone cutthroat trout. They also fault the agency for "surgically delisting" the isolated Yellowstone grizzly population instead of focusing on a broader, more durable grizzly recovery in the West.

Since 1975, Yellowstone-area grizzly bears have been listed as threatened under the Endangered Species Act. Federal biologists acknowledge that population growth of the Yellowstone grizzly bear has flattened over the past decade and their own data indicates a decline from 2014 to 2016, the groups said last summer. Prior to and during that same period, the grizzly population has faced the loss of two of its most important food sources in the Yellowstone region—whitebark pine seeds and cutthroat trout—due to changing environmental conditions driven in part by a warming climate.

The Fish and Wildlife Service previously attempted to delist the Yellowstone grizzly population in 2007, but that decision was overturned by a federal district court in Montana along with the 9th Circuit Court of Appeals on the basis that the Service ignored the impacts of the whitebark pine loss on the grizzly population. In rejecting the Service’s 2007 grizzly delisting decision, the 9th Circuit admonished the agency that “the Service cannot take a full-speed ahead, damn-the-torpedoes approach to delisting—especially given the ESA’s ‘policy of institutionalized caution.’”

Following Thursday's decision, the judge must decide rule whether Fish and Wildlife Service staff have properly determined that the species has recovered enough to go without ESA protections.

“As we explained to the judge today, the removal of protections for Yellowstone’s iconic grizzlies was illegal. The bears should not be killed in a hunting season made possible by an illegal government decision,” said Tim Preso, Earthjustice attorney, in reacting to the TRO approval.

Earthjustice had sought the temporary restraining order on behalf of the Northern Cheyenne Tribe, Sierra Club, Center for Biological Diversity, and National Parks Conservation Association.

In reaching the decision to issue the TRO, the judge cited a 9th Circuit ruling from this year in which that court held that in Endangered Species Act cases, "the Court presume[ s] that remedies at law are inadequate, that the balance of interests weighs in favor of protecting endangered species, and that the public interest would not be disserved by an injunction."

Lawyers for the Fish and Wildlife Service and the state of Wyoming did not appear at Thursday's hearing to argue why the decision to delist was correct and that the hunts should go forward as scheduled.