A judge has temporarily blocked grizzly bear hunts around Yellowstone National Park and the Rocky Mountains two days before it was due to start.

The federal judge yesterday put a hold on the opening of the first grizzly bear hunts to be held in the Rocky Mountains in more than 40 years.

US District Judge Dana Christensen's order came just two days before Wyoming and Idaho prepared to began the first hunting season of grizzly bears in the area since 1974, due to start tomorrow.

Yesterday's ruling was seen as a victory for wildlife campaigners and Native American tribes that sued over the US Fish and Wildlife Service's decision in 2017 to lift protections for 700 bears in and around Yellowstone National Park.

A grizzly bear cub searches for fallen fruit beneath an apple tree a few miles from the north entrance to Yellowstone National Park in Gardiner, Montana

Federal wildlife officials said the bears are thriving and do not need protecting, but animal activists, acting as the plaintiffs, argued the bears still face threats to their survival.

Judge Christensen wrote in her ruling: 'The threat of death to individual bears posed by the scheduled hunts is sufficient to justify a delay in the state's hunting seasons.'

A final decision on whether the hunt can resume in the future will be made by the judge at a later date.

Fewer than two dozen bears would be allowed to be killed in the hunts.

Mike Garrity, the executive director for plaintiff Alliance for the Wild Rockies said: 'We're thrilled. Now the judge has time to rule without grizzly bears being killed starting Saturday morning.'

Fewer than two dozen bears would be allowed to be killed in the hunts.

Frequent grizzlies attacks on livestock, the impact bears have on populations of deer and elk as well as the threat grizzlies pose to humans, were cited as reasons for hunting the wild creatures.

A small group of grizzly bear advocates protest outside the US District Court in Missoula, Montana, in a bid to restore federal protections for a group of about 700 grizzly bears

But Todd Hoese, an accountant and hunter from Gillette, Wyoming, expressed disappointment in Judge Christensen's ruling and applied for but did not receive a grizzly bear hunting tag.

He said: 'They're just looking at it from the bears' perspective. The way that nature works is a balance and we don't have that balance. There are too many bears now.'

Prior to Christensen handing down Thursday's order, Wyoming officials said they were willing to make adjustments to the state's hunting season, but placed a condition on doing so.

Erik Petersen, Wyoming's senior assistant attorney general suggested the judge leave Wyoming, Montana and Idaho in charge of managing the bears.

He said: 'The likelihood of any significant harm to the population is essentially nil.'

A judge put on hold the Lower 48 states' first grizzly bear hunting season in more than four decades, which was due to open around Yellowstone National Park this weekend

Hunt opponents claim the US Fish and Wildlife Service's decision last year that Yellowstone grizzlies are no longer a threatened species was based on faulty science.

They also say they don't trust that the three states that have taken over bear management will ensure the bears' survival. They want the judge to re-classify the bears as threatened.

Among their arguments in court, attorneys for advocacy groups questioned how other threatened grizzly populations in the Lower 48 states would fare if the Yellowstone bears' status changed.

They also said the federal wildlife agency ignored recent spikes in overall bear deaths that, when hunting is added to the mix, could cause an unanticipated population decline.

Department of Justice attorneys said the Fish and Wildlife Service considered all the plaintiffs' arguments and proceeded with lifting protections because there was no threat of extinction to the bears now or in the foreseeable future.

Petersen and attorneys representing Montana and Idaho said the people most affected will be the farmers and ranchers who live in grizzly territory and have increasing conflicts with bears attacking livestock.

The population of grizzlies living in Yellowstone was classified as a threatened species in 1975, when its number had fallen to 136.

The Fish and Wildlife Service initially declared a successful recovery for the Yellowstone population in 2007, but a federal judge ordered protections to remain in place while wildlife officials studied whether the decline of a major food source, whitebark pine seeds, could threaten the bears' survival.

In 2017, the federal agency concluded that it had addressed all threats, and ruled that the grizzlies were no longer a threatened species needing restrictive federal protections.

A grizzly bear in Yellowstone National Park, Wyoming, where hunts were due to begin for the first time in 40 years until a judge temporarily blocked the opening of the season

That prompted six lawsuits challenging the agency's decision. Those lawsuits have been consolidated into one case that Christensen heard on Thursday.

Idaho's hunting quota is one bear, whereas Wyoming's hunt is in two phases, including September 1 when the hunt opens the season in an outlying area with a quota of 12 bears.

Then two weeks later starts the season in prime grizzly habitat near Yellowstone and Grand Teton national parks. One female or nine males can be killed in those areas.

It would be Wyoming's first grizzly hunt since 1974 and Idaho's first since 1946.

Twelve hunters in Wyoming and one in Idaho have been issued licenses out of the thousands who applied.

Montana officials decided not to hold a hunt this year and the state held grizzly hunts until 1991 under an exemption to the federal protections that allowed 14 bears to be killed each fall.

Bear hunting is not allowed in Yellowstone or Grand Teton.