Big Male Grizzly Bear Is First To Wake Up From Hibernation at Yellowstone

The first grizzly bear to be seen in Yellowstone National Park this year has been filmed after emerging from hibernation.

Adult male grizzlies typically emerge in early March in the park. Safety warnings were issued by the NPS in anticipation of the re-emergence of the bears. Several trails where deer or elk carcasses could attract bears will be temporarily closed from Thursday.

The National Park Service said that the adult male bear was seen on March 7 by a pilot supporting the park's wildlife research team. The animal was first spotted walking in a meadow in the western-central part of the park.

Kerry Gunther, the park's bear management biologist, provided safety advice to visitors.

"Spring visitors hiking, skiing, or snowshoeing in the park can reduce the chances of encountering bears by avoiding low elevation winter ranges, thermal areas, and south-facing slopes where bears seek out ungulate carcasses and spring vegetation shortly after emerging from winter dens," she said in a statement.

Grizzly bears hibernate during winter for five to six months amid a shortage of food.

Footage posted on the NPS Yellowstone Facebook page showed bears searching for food after emerging from their winter hibernation.

Frank T. van Manen, supervisory research wildlife biologist with the U.S. Geological Survey, told Newsweek previously: "During hibernation, they reduce their metabolism to about 25 percent of active metabolism and heart rate by 20 percent to 45 percent during denning. However, the decrease in body temperature is only moderate (36 to 46 degrees Fahrenheit).

"There is not much food available upon emergence from the winter den, so they initially look for easy food sources such as winter-killed ungulates [like elk]. Many bears still rely on their fat reserves upon den emergence, and only start gaining weight again when more foods become available later in the spring."

NPS said that adult male grizzlies can store up to one million calories in their fat reserves to help them survive over winter and spring while they wait for food to become more readily available. The bears lose up to 40 percent of their weight during hibernation, meaning they are hungry and immediately on the lookout for food after they wake up.

Grizzly bears are omnivorous and eat up to 266 different species of plants and animals in Yellowstone. The majority of those species are plants (67 percent), followed by insects and other invertebrates (15 percent), mammals like deer and elk (11 percent), plus fish and fungi.

Stock image of grizzly bear in Yellowstone
Stock image of grizzly bear in Yellowstone. Adult males typically emerge from hibernation in early March. They can store up to one million calories of energy in their fat reserves to survive over the winter. Jill Richardson/Getty Images