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Home > Research & Collections > News > California’s Grizzly Past

California’s Grizzly Past

Could these bears roam the golden state once again?

Grizzly bear at the San Diego Zoo. Grizzly bears, a type of brown bear, are found across North America, Europe, Asia, and even the Middle East. Photo by Ronald Woan.


The California grizzly bear adorns the state flag, and countless schools use it as a mascot, but there hasn’t been a grizzly bear in California since the early 1920s. In biology lingo the grizzly bears were extirpated from California — that is, extinct in a particular region.

But in 2014, the Center for Biological Diversity proposed that California — as well as Arizona, New Mexico, and Utah — should be listed as habitat for grizzly bears, suggesting that the California Department of Fish and Wildlife might someday reintroduce these iconic animals to the state, possibly in the Sierra Nevada mountains.

a photo of bear jaws in a drawer
A drawer of California grizzly specimens at the Smithsonian's mammalogy collections warehouse.

But before anyone seriously considers that, we have to know a few things. For one, what exactly did they eat when they were here? Did their diets vary across the state? We need to understand what resources they depended on in the past so we can determine what parts of California might still be suitable for them today and into the future.

Grizzlies are omnivores; they eat just about anything. They can eat mushrooms, insects, rodents, fish, deer, berries, roots, nuts, and grasses. With such a wide menu of options, they adjust to the season and their surroundings, tailoring their diet accordingly. But most of what we know about grizzly diets comes from studying bears in Yellowstone, Canada, and Alaska — places very different from California. What did they used to eat in the golden state?

“We don’t have the answers, because by the time anyone was interested in studying California’s grizzlies scientifically, they were already gone,” said La Brea Tar Pits Postdoctoral Research Fellow Alexis Mychajliw.

But with a better-late-than-never spirit, Mychajliw and collaborators with the California Grizzly Research Network at UC Santa Barbara are studying them today, by using whatever bits and pieces they can find in museum collections across the U.S.

a photo of a bear skull with a big hole it in
A bear skull with a bullet hole, from the Smithsonian. Writing collection information directly on the skull is not today’s standard (usually it’s just a catalog number), but in this case, it’s helpful in confirming that the bear was from California.

Unfortunately, there aren’t too many California grizzlies in museum collections; there are less than 60 individual grizzly skins, claws, and bones with enough reliable information to show they were definitely from California. Mychajliw and her collaborators are tracking these individuals down across a variety of natural history museums and research institutions, including fossil collections, such as at the La Brea Tar Pits.

“Each bone tells a story, whether a skull has extremely worn teeth suggesting it was old when it was collected, or bullet holes showing it was a large male hunted in its prime. I feel like I’ve gotten to know each one of these bears individually,” says Mychajliw.

Most importantly, Mychajliw is removing small samples of bone for stable isotope analysis: by looking at the different ratios of carbon and nitrogen isotopes (different forms of these atoms), we can actually tell a lot about a bear’s diet. The old adage is true; you are what you eat. Your bones and hair reflect the chemistry of foods you consumed.

two grizzly bear lower jaws, which are chocolate brown because of the tar pits.
Mandibles of California grizzlies from the La Brea Tar Pits.

We can tell if a bear was eating more plants or more meat, but that’s not all. Isotope ratios can tell us if the majority of meat a bear ate was from a land animal like a mule deer or an aquatic animal like a fish or whale (which bears have been known to scavenge when they wash ashore). We can even tell if the plants they ate were succulents or shrubs, because those plants have different ratios of carbon isotopes. By looking at individuals from different time periods — hundreds to thousands of years old — the team can also get an idea of just how flexible California’s grizzlies were over time as they faced environmental changes.

Among the grizzly skeletons Mychajliw sampled, she came across Monarch, the individual bear whose portrait adorns the California flag. In 1889, this California grizzly was trapped in Ventura County and taken to the San Francisco Zoo, where he remained until his death in 1911.

And today, over 100 years later, the bear who became our symbol will also help us peer into California’s grizzly past.

the California state flag features a bear on a white background
The grizzly bear was designated the California state animal in 1953, almost 30 years after it disappeared from the state. The bones of the bear portrayed on the California state flag will help us understand California’s historic grizzly population.



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