The day before, we'd heard a talk by Be Bear Aware program leader Stephanie Coppeto about black bears. They are fascinating creatures. Did you know that a bear's sense of smell is seven times more sensitive than a bloodhound's? That means they can smell food (including whatever's in your bear canister) from at least a mile away, and some estimates say they can smell a fresh carcass up to twenty miles away. Stephanie described their sense of smell this way: if we can smell chocolate cake, they can smell the flour, eggs, butter, milk, cocoa, and vanilla, individually.
There are sixteen subspecies of U. americanus (ours is californiensis), all found in North America, and they are not all black but range in color from black to blond to white, with brown being common in the Sierra. They number between 700,00 and close to 1 million, half in Canada, the rest in the U.S. down into the mountains of northern Mexico.
Eighty-five percent of their diet consists of vegetation—roots, tubers, berries, grasses, nuts—supplemented by insects and insect larvae, honey, fish, and carrion. In other words, they eat everything, and if they live near human habitation where trash isn't properly contained, they'll happily eat trash. Stephanie said that they hibernate not so much because of cold but because they run out of ready food supplies. Those bears that do live near towns have been known to wake up every week on trash day to come down and scavenge, returning at the end of the day to their dens.
interactive map for the Sierra), how best to cache them. Essentially, you want to keep it away from your sleeping and cooking/eating areas—which themselves should be at least several dozen feet apart—but you want it close enough that you can hear if a bear comes in the night and decides to mess with it. At which point you should emerge from your tent and yell at it. It will go away. Bears are pretty shy, unless that become habituated to us—or more specifically, to the food we leave lying around.
Stephanie finished by showing us a funny video of a bear trying its darnedest to get into a bear canister. Oh, if only for opposable thumbs!
We've encountered bears a few times in the backcountry. Once we were backpacking with a friend. We'd hung our food (no longer a recommended approach: black bears climb, and their cubs are very agile), and our friend went off to pee; when he came back, he was in a panic: "Bear!" he shouted. He was a joker, and we thought he was kidding, until he led us over and we saw for ourselves in the light of a headlamp. We yelled and banged pots, and it eventually ambled off. And then snuck back. We yelled; it left. This happened a few more times. I vaguely recall that it actually did get one of our bags, because I remember bear slobber. All over everything.
Another time, we wanted to cross over a footbridge spanning the Merced River up above Vernal or Nevada Falls, but the way was blocked by a bear delicately making its way into a can of roasted, salted peanuts, which it had extracted from a backpack that lay nearby. We eventually decided if we were going to get anywhere, we'd just have to march past. It didn't even look up as we tiptoed by.
The most interesting encounter was when we were walking along the Panorama Trail from Glacier Point. We'd just passed Illilouette Falls when we noticed a darling little bear cub romping up a tree. We shifted our gaze a little, and there stood Mamma. Uh oh. We weren't in between Mamma and her cub, but nevertheless, she didn't look happy. We scampered off the trail down the hillside and continued on, bushwhacking now. Mamma took to the trail and paralleled us. For quite a distance. Once we lost sight of her, we stayed down in the steep brush a while longer, just in case. It was a relief to regain the trail and see no sign of Mamma bear. It was on that hike that we encountered our very first morel as well, though we knew nothing about mushrooms at that point so were only guessing with our identification. If we'd known, we might have picked it (illegally, I know) and cooked it up for dinner. But our ignorance left it intact.