California Bears, Past and Present

If asked to think about "large wild mammals," many Angelenos would envision a scene on the African savanna: images of vast herds of wildebeests and zebras, scatterings of rhinos and elephants, as well as the lions and cheetahs that prey on them have been vividly etched into our minds through television programs and visits to the most exotic residents of the zoo. Few of us would instead conjure up a mental picture of southern California, but in fact our neighborhoods were teeming with similar large mammals a mere 20,000 years ago. The evidence of the former inhabitants comes from Rancho La Brea asphalt deposits.

At the end of the last Ice Age (just yesterday in geological time), camels, bisons, mammoths, lions, saber-toothed cats, and packs of wolves roamed the Los Angeles Basin. Had we lived here then, we also would have shared territory with the short-faced bear, Arctodus simus, perhaps the largest and most powerful predator in North America at the time. When fully grown, the male of this snub-nosed, long-legged carnivore was immense, as much as 2 feet taller at the shoulder than the largest grizzly or polar bear and-- at 1,500 to 1,800 pounds-at least 500 pounds heavier than the modern species.

The short-faced bear may have been more of a carnivore than its living relatives: its stubby muzzle put its strong, stabbing canine teeth in a position to bear down in a very forceful bite, and the architecture of its skull suggests that it had extremely powerful jaw-closing muscles. Its long limbs made it capable of running faster and farther than do modern bears; it may have chased down and killed its prey, which undoubtedly included some of the large herbivores found at Rancho La Brea.

The short-faced bear along with the other large mammals that ranged through our basin in the late Pleistocene met their demise around 10,000 years ago. While the reasons for these extinctions may be complex and are not yet fully understood, the expansion of populations of people may have contributed significantly to the worldwide disappearances of many Pleistocene animal species, especially the large mammals and birds. The ancient human hunters of southern California, who had only recently arrived on the West Coast, probably had no idea that their actions might forever change the landscape and vistas of wildlife in their new home.

Paleontologists working at Rancho La Brea have unearthed the remains of more than thirty individual short-faced bears-- as well as fewer bones of two other bear species, the black and the grizzly. The grizzly bear, Ursus arctos, has been found only in the tar pits' most recent deposits, because this animal did not appear in the region until late in the last Ice Age. In writing about members of the bear family at Rancho La Brea, our Chief Curator of Paleontology John Harris noted that, at the end of the Pleistocene, "forms most closely related to types now living in California were distinctly outnumbered by bears of a kind now extinct. However, with the disappearance of the short-faced bears, the black and grizzly bears established themselves as the prevailing representatives of the family in California."

The grizzly (also known as the brown bear) and the black bear, Ursus americanus, thrived in our state until their interests again clashed with those of the human populations. In historic times, grizzlies were hunted to protect people and their livestock. These bears were also used in the last century in a cruel blood sport, in which a grizzly was pitted against a bull in a battle to the death. The last grizzly in the wild in southern California (reputed by some to be an escapee from a local zoological garden) was shot in 1916 just above the Los Angeles foothill community of Sunland. And the last grizzly in the entire state was killed in 1922 on a ranch outside of Fresno.

Although the grizzly bear's image still emboldens our state flag, the once widespread species-which still ranges in the far northwestern regions of North America-- is now extinct in California.

California’s sole remaining bear species is the black bear, whose common name is something of a misnomer: although many individuals are black, others are dark brown or cinnamon, and there is even a population in the Pacific Northwest with a high percentage of white individuals. While color alone cannot always be used to distinguish between black and grizzly bears, other features are more reliable: grizzlies have longer claws and a large distinctive hump on their backs at the shoulder. In parts of the continent where the two species are found together, black bears tend to reside in dense forest or brush, while grizzlies prefer more open country.

Grizzlies and other bears, along with a number of familiar mammals (dogs, cats, skunks, and raccoons, for example) have been placed in the order Carnivora by taxonomists, to reflect the fact that they are primarily meat eaters. However, some members of the order, including most of the bears, do not live up to this billing. About 80 percent of the black bear's diet consists of vegetation and fruit, and their "meat" is most often insects, such as grubs, termites, and ants. (Among the bears, only the polar bear eats primarily meat-its habitats in the high Arctic are virtually devoid of plant matter. And another bear, the giant panda of China, feeds almost exclusively on bamboo, making it the most vegetarian of all of the Carnivora.)

The catholic diet of black bears sometimes brings them out of the woods into rural or suburban areas in search of an easy meal, typically from our garbage cans. As Allan Schoenherr describes (see "Camptown Raiders," page 7), some bears in campgrounds and national parks have acquired the junk food habit, with unhappy consequences for bears and people alike.

Because of their size and occasional aggression toward humans, bears have a reputation as beasts to be feared. But in fact they typically avoid humans whenever possible, and we can further minimize the chances of an unfavorable encounter. Because some bears have poor eyesight, a quiet hiker runs the risk of startling one. Needless to say, a bear considers this poor etiquette: hikers should make noise as they traverse bear country. Curling up in a sleeping bag surrounded by rich, aromatic foods is also not advisable. And feeding bears-or any other wild animal-is always an invitation to trouble.

We know that the short-faced bear will never again amble through the Southland, and it will be years-- if ever-- before grizzlies come back to our state. The black bear is thus the last bear species left in our wilderness areas. As home construction and recreational activities encroach on black bear territory, people and bears will continue to interact. It is incumbent on us to ensure that these meetings are as safe as possible for both species.

JOHN E. HEYNING

Deputy Director, Research and Collections

In addition to heading the research and collections branch of the Natural History Museum, Dr. Heyning is curator of mammals. His lifelong interest in biology began when as a small child in Torrance he captured and tried to domesticate side-blotched lizards and gopher snakes. Frequent bike rides to the tide pools of Palos Verdes introduced him to marine biology, a passion that led to his specializing in the biology of marine mammals. His research on these creatures has been featured in National Geographic, Discover, and New Scientist magazines. He lives in Hermosa Beach with his wife Corinne, two children, two cats, seven turtles, and nine species of palms.

Originally printed in Terra, Vol.36 No.6, Fall 1999, p. 6-9.