SALMON, Idaho (Reuters) - Environmental groups sued the U.S. government on Wednesday for stripping federal protections from grizzly bears in and around Yellowstone National Park, contending climate changes and poaching threaten the famed population of bears.

WildEarth Guardians as well as a coalition including the Sierra Club and Northern Cheyenne Tribe separately sued Republican President Donald Trump’s administration in U.S. District Court in Missoula, Montana to prevent removal of the bears from the U.S. list of endangered and threatened species.

“Grizzlies have disappeared in nearly 98 percent of their range in the Lower 48; now is not the time to strip these bears of vital federal protections,” WildEarth Guardians carnivore advocate Kelly Nokes said in a telephone interview.

Grizzlies are a top attraction for the millions of visitors to Yellowstone each year, sometimes drawing vehicles packed with tourists in “bear jams.”

The lawsuits, which name U.S. Interior Secretary Ryan Zinke and the U.S. Fish and Wildlife Service as plaintiffs, claim that illegal killing and climate changes have caused declines in the grizzlies’ food supplies and habitat loss. These factors threaten the survival of the large, hump-shouldered bears that roam Yellowstone and the three Northern Rocky Mountain states that border the park, according to the lawsuits.

The groups are asking a federal judge to find that the U.S. government violated provisions of the Endangered Species Act in delisting the bears and to retain safeguards.

The U.S. Fish and Wildlife Service referred questions to the Department of Justice, which declined to comment on Wednesday.

Zinke, a former Montana congressman, in June hailed the plan to lift the protections as “one of America’s great conservation successes” due to the animals’ rebounding population.

Yellowstone area bears were delisted in July, opening the door for trophy hunting outside the park in Wyoming, Montana and Idaho.

Grizzly numbers in the region have climbed to roughly 700 from 136 in 1975, when the bears were listed as threatened in the Lower 48 states after being hunted, trapped and poisoned to the brink of extinction.

Hunters strongly supported delisting the bears, considered trophy game animals.

Ranchers, who have long held political sway in the region, said the bears’ growing numbers threaten humans and livestock, while the energy and extraction industries chafed against restrictions imposed on oil and gas development, mining and logging tied to grizzly habitat protections.