If you've come to Yosemite National Park looking for megafauna, then it's black bears that you'll want to be watching out for. The largest mammal in the Sierra Nevada mountains, a full-grown adult male black bear typically weighs between 300 and 350 pounds, although the largest ever caught inside the park weighed a whopping 690 pounds! Despite their name, black bears have fur that ranges in color from coal black and nut brown to light tan, cinnamon red, or even golden blond. If you spot a patch of white fur on their chest, it's called a blaze.
Black bears are omnivores, although you'll most often see them foraging for berries and eating acorns and grasses in the meadows and mixed conifer forests of the Sierra Nevada range. They also rip up logs to eat those tasty insects underneath the bark. In the wild, black bears can live for up to 25 or 30 years. They are generally solitary animals, except for a sow and her cubs, which generally live together during the first year of the cubs' life. Most black bears den during winter, whether that means finding an underground cave or settling into a hollow tree trunk. Some black bears remain active throughout the winter, especially at lower, and thus warmer elevations in the Sierra Nevada foothills.
Incidentally, the last grizzly bear was extirpated from California in the 1920s, so any bear that you see while in the Sierra Nevada is definitely a black bear, and not a brown bear or a grizzly bear. Both of the latter species have distinct shoulder humps, which black bears do not. The behavior of black bears is very different from grizzlies; black bears that have not been habituated are naturally afraid of human contact, generally speaking. To them, you actually seem like the bigger threat, unless they've already grown used to humans (e.g., ambling along hiking trails, camping in the forest) or you clearly act in a submissive manner (e.g. running away or climbing a tree).
Black Bear Safety Tips
There are some very important tips to keep in mind when traveling in black bear country throughout the Sierra Nevada range. Because black bears may be active year-round, especially in heavily populated areas such as the Yosemite Valley, you should take precautions both to protect yourself and to help keep black bears wild. Habituation to humans can make black bears more aggressive and eventually they may be have to be shot if they become a public safety hazard -- something that no one wants to see happen.
Encountering Black Bears in the Wild
The best advice if you encounter a bear in the wild is to stay calm and enjoy the chance to observe the bear behaving naturally. Gather small children to your side, picking up the youngest ones, so that your group looks larger and more imposing. Stay at least 300 feet away from the bar, using a zoom lens to get a better look rather than approaching the animal too closely. Never get between a sow and her cubs, and never block a bear's escape route (i.e., don't stand on the trail). Remember that bears can run up to 35mph, so never try to outrun them. If a bear approaches you, yell and shout loudly and try to make yourself look bigger (e.g., waving hiking sticks above your head). Standing your ground may convince the bear to go away and leave you alone. Otherwise, back away slowly and move off to the side of the trail to let the bear pass by.
Protecting Black Bears in the Front Country
In developed areas of the park, including all parking lots, lodges, and campgrounds, you must be vigilant at all times about food storage. All food, trash, and scented items -- which includes empty coffee cups, recycling containers, wrapped candy and mints, children's car seats, sunblock and mosquito repellent, cigarettes and ashtrays, coolers whether empty or filled, etc. -- can attract a bear to break into your car or enter your campsite.
Black bears are extremely curious creatures, so they'll try eating anything with an unusual smell, thinking it might be food. Once a bear gets a food reward, it can quickly change their natural behaviors, encouraging them to steal food and trash from park visitors and eventually making them aggressive. Those bears that you see wearing colored ear tags and radio collars in the park are those that have already gotten food rewards and have become habituated to human visitors. Help park rangers keep these black bears wild by safely storing all food, trash, and scented items in bearproof containers provided at park campgrounds, trailheads, and parking lots. Where these are not available, lock everything that might attract a bear into the trunk of your car or at least out of sight inside your vehicle (e.g., cover coolers with blankets, draw the curtains in RVs).
In 1998, there was a record of 1,584 bear incidents eating stolen food or garbage. In 2014, the Park reported a 63% reduction in incidents. Thank you Park guests, for being vigilant and helping to save our bears. (reference)
For more interesting information and tips about black bears, visit www.sierrawildbear.gov.