The first sign of spring in Yellowstone National Park is not a flower or a bird singing, but the sighting of the first grizzly bear to emerge from hibernation.

This is the second year that wildlife biologists have spotted the first grizzly on March 7. Apparently, that is the first day of spring to male grizzlies.

This year the 300-pound bear was spotted near a bison carcass in Pelican Valley. Park officials shared, "Male grizzlies come out of hibernation in early March. Females with cubs emerge in April and early May. When bears emerge from hibernation, they look for food and often feed on elk and bison that died over the winter. Sometimes, bears will react aggressively to encounters with people when feeding on carcasses."

An estimated 150 grizzlies and over 500 black bears live in Yellowstone National Park. The entire park is considered bear country and visitors should carry bear spray and follow the bear safety guidelines provided by the park rangers.

While bear attacks are rare (roughly one a year), visitors are urged to stay alert and keep at least 100 yards away from all bears.

The "A Bear Doesn't Care" campaign, featuring familiar faces like Jeff Bridges, hopes to encourage everyone to carry bear spray. According to the park, only 28% of visitors carry bear spray which may save your life.

Bear spray is non-lethal and a highly effective deterrent at stopping aggressive bear behavior.

"Yellowstone visitors care deeply about preserving bears and observing them in the wild," states Kerry Gunther, Yellowstone's Bear Management Specialist. "Carrying bear spray is the best way for visitors to participate in bear conservation because reducing potential conflicts protects both people and bears."

Gunther goes on to warn spring visitors to be on the lookout for hungry bears as they emerge from hibernation.

"Spring visitors skiing, snowshoeing, or hiking in Yellowstone National Park are reminded to carry bear spray and be especially alert for bears near carcasses and areas with early spring green-up. These are the first foods sought out by grizzlies after emerging from hibernations."

Learn more about the grizzlies that call the park home here.