Science Natural Science Yellowstone Grizzlies Back on Endangered Species List By Andrea Donsky Updated October 11, 2018 Migrated Image Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy A grizzly bear in Yellowstone National Park. Photo by Fidelis Orozco via Flickr. Two years after the grizzly bears of Yellowstone Park were removed from the Endangered Species List, a federal district judge in Montana has ordered the bears be placed back on it. According to United States District Court Judge Donald Molloy's 46-page ruling, the re-listing of the bears was necessary to protect the species from the inadequate population management regulations, and the poor attention to the decline in whitebark pine, the seeds of which are a key source of food.Endangered Species Protection NecessaryIn 1975, the Yellowstone grizzly population hovered somewhere between 136 and 312 bears, and while the 2007 population estimate of 500 bears was a significant improvement, the bears were clearly not out of the dark. Yet they were removed from the Endangered Species List, and the population management fell into the hands of Idaho, Wyoming, and Montana. According to Judge Molloy's ruling, the conservation strategy set a standard that the population should not fall below 500 bears, but it did not list any standards on how to maintain the bear's population levels. Unenforceable standards and monitoring protocols were two of the primary reasons the grizzly was placed back on the Endangered Species List. The bear's survival depends on their Endangered Species designation, Judge Molloy concluded: Without the protections of the (Endangered Species Act), the Yellowstone grizzly bear ... will be placed in jeopardy. Bears' Food Source ThreatenedThe Yellowstone grizzly feeds heavily on whitebark pine nuts in the fall. Whitebark pine is expected to continue to decline in the years to come "due to a variety of causes, including climate change, increased forest fires, the mountain pine beetle epidemic, and infection by white pine blister rust," Judge Molloy wrote in his ruling.While the U.S. Fish and Wildlife Service (FWS) argued the bears would find another source of food to fill any void, the judge noted that in years when whitebark pine nuts are in short supply, statistics show there are more incidents involving humans and grizzly bears, ultimately resulting in the bears being killed. Genetic Diversity Not A Problem...YetThe Yellowstone grizzly population has been isolated for a century and declining genetic diversity could make them vulnerable in the future. The judge noted that there is currently enough genetic diversity that they probably won't be at risk for some time, but there could come a day when it does threaten the species. Another important aspect of the judgment was the current plan for maintaining the diversity of the species. In the event that the Yellowstone grizzlies do not reconnect with another grizzly population by 2020, the FWS will begin to introduce one or two grizzlies to the population each generation. But there's a hitch: Bears from other U.S. grizzly populations that could be transplanted to the area are also endangered, so they would be reducing those populations to ensure the survival of the Yellowstone grizzlies. Not only is this plan dependent on the health and growth of other grizzly populations, it's further evidence that the Yellowstone grizzly population is not currently self-sustaining, and that it requires the protections of the Endangered Species Act, the Greater Yellowstone Coalition (the plaintiff) argued. Thankfully, the judge agreed and the bears are once again protected.