Scientists criticized a federal report recently released suggesting that Yellow Stone grizzly bears should be removed from the Endangered Species list because their food resource is not scarce.

According to report presented to the Yellowstone Ecosystem Subcommittee of the Interagency Grizzly Bear Committee, the grizzly bears are not threatened because their survival is not associated to loss of white bark peanuts, which is the bears’ main food source.

The U.S. Fish and Wildlife Service report said that the whitebark pine trees that are affected by the tree-fatal beetle epidemic are only 16 percent and therefore should not cause panic in terms of the grizzly bears’ population.

However, former U.S. Forest Service's bark beetle research unit head Jesse Logan criticized this report. He told told LiveScience.com: "We were able to launch a study in the summer of 2009 to measure the impact of mountain pine beetles in whitebark pine. What we found was, rather than 16 percent had been impacted at some level, 95 percent had been impacted."

He said that the report is just a rosy-painted picture that covers the truth: the main grizzly habitat is significantly affected by the beetle outbreak, which is far from declining.

Other wildlife advocates and scientists are also fighting against the proposal of delisting of the grizzly bears from the Endangered Species list.

"There is not a single positive trend afoot in Yellowstone's grizzly bear habitat," according to David Mattson, a grizzly bear expert and a visiting senior research scientist and lecturer from Yale University.

Both Mattson and Logan believe that the federal report downplayed on the real situation since it does not study other factors to the health risks of grizzly bears apart from the pine trees. Other food sources are becoming scarce and human-caused bear deaths are also on the rise.

Thus delisting of the grizzlies will allow more bear hunts as the federal protection will be lifted. "One of the first things the states are going to do is, in fact, institute a sports hunt. They've said so," explained Mattson.

As it is, the grizzly bears are on a tight situation but keeping the federal protection would provide some hope for these bears. This "makes it more likely that bears can continue to spread out into areas we know are suitable for bears," said Mattson.