We’re about to finish checking our bird traps at Tioga Pass when I spot it– a moving black lump in the upper right hand corner of my eye. We freeze.
“Holy–” I say. “Is that…?”
I slowly raise my binoculars. It is. Standing on a boulder, huffing its huge steaming snout in the morning air, is a black bear (Urus americanus). Judging by the size, it’s young. A couple of years old, probably. But still much too big to get close to.
“Yeah,” says the grad student I’m working with. “Let’s not go that way.”
We turn around and abandon the rest of the traps for the day. Then, half an hour later, as we’re measuring a white-crowned sparrow caught in our trap, I hear the willows rustle behind us.
“Oh my god.” I lift my neck from the notebook. There it is again, a little over ten paces away in a big willow bush. I can see a pair of shiny black eyes and a red tag dangling on its ear. It’s looking in our direction. “Don’t wanna alarm you,” I mutter quietly. “But now it’s right behind us.”
“No.” says the grad student, not looking up from the bird.
“Yep.”
Once we safely let the bird go, we begin to yell and clap our hands. The bear perks up, stares at us, and reluctantly begins to plod its way back through the willows, which crunch under its heavy footsteps.
It was our first bear encounter. That youngster probably didn’t mean us any harm– it just wanted the seeds we’d been baiting our traps with. Still, the closeness of the encounter– the bear’s seeming lack of fear– served as a great reminder. All across California, people are more frequently coming into contact with the black bear, who inhabits forests, mountains, and now even urban spaces throughout North America.
Contrary to what their name might suggest, you won’t be able to identify this bear species by color. A black bear’s “pelage,” or fur, can be black, light brown, dark brown, “cinnamon”, blond, or even white and silver, like the Kermode and Glacier bears of British Columbia. Black bears’ fur color often differs even between closely related individuals like siblings [1]. Even without a color guide, identifying a black bear shouldn’t be too tricky. As a species, black bears are much smaller in size, lack a shoulder hump, and are much more widely distributed than brown bears (Ursus arctos) of Fat Bear Week fame.
Some of the variability in color might come from variety in black bear diets. Black bears are known to mostly eat shoots, grasses, roots, nuts, and fruit, especially berries, but their diet can also include fish, eggs, carrion, the very occasional young or weak deer, and plentiful insects [2]. On islands off the coast of British Columbia where black bears feed predominantly on salmon in autumn, about 20% of the black bears are white [3]. This looks odd at first – lighter colors seem like poor camouflage from potential prey in dark forest environments [4]. Scientists set out to find out if the color differences were associated with any difference in hunting efficiency. They videotaped bears attempting to catch salmon during the day and night [3]. They found that white-colored black bears were better at catching fish during daylight hours than black-colored black bears – with a nearly 10% higher success rate! This is likely because the fish have a harder time seeing lighter-colored bears against the sky when it’s light out. In a population where eating enough salmon during the autumn is critical to making it through the cold winter, this difference may be a sufficient advantage to give white fur a leg up in this population [3].
Side note, Smokey Bear was a real bear in fact. While small wildfires present foraging opportunities for bears (burned grubs, yum!), large megafires like those of recent years pose a risk to bears, as well as other native California wildlife.
Black bears tend to be solitary. Individual bears can roam areas dozens of square miles wide where they spend most of their time, called home ranges [4]. As cubs grow up, most males leave the area where they were born, traveling an average of almost 40 miles to find new mating opportunities elsewhere [5]. A smaller proportion of young females will also leave [5]. Given that humans have developed the periphery of bear habitat, young bears are at risk as they cross roads and enter urban areas. While the American black bear isn’t currently threatened with extinction, their total range has decreased with urbanization, and the closest relative the Asiatic black bear (Ursus thibetanus) is listed by the IUCN as vulnerable due to forest habitat loss and overhunting as their body parts are sold for traditional medicine [6].
Due to the combination of their opportunistic diets, flexible habitat requirements, keen navigation, and incredible senses of smell, black bears often find themselves in human-altered environments, including campsites, farmlands, suburbs, and cities. And that means access to bountiful, overflowing garbage bins. Eating garbage is bad for bears beyond the nutritional deficiencies – it makes them used to people, which can lead to unusually aggressive behavior around people. It also puts them at risk to vehicle traffic and poachers. That’s why it is very important to always store food properly in bear-proof containers when visiting national parks, forests, or any other bear habitat.
Most wild animals that like to hang around people are small and skittish. The black bear is a reminder that the biggest, furriest species out there are affected by our presence too, and that “wilderness” isn’t some other place we go to– it’s all around us. Whether it’s looking for rivers, garbage bins… or apparently, birdseed traps… the multicolored black bear is on the move, and it’s going to follow its nose.
Alice Michel is a PhD student in the Animal Behavior Graduate Group. She studies how furry animals with vague territorial systems adapt to environmental change.
References
[1] Rounds, R. C. (1987). Distribution and Analysis of Colourmorphs of the Black Bear (Ursus americanus). Journal of Biogeography, 14(6), 521. doi: 10.2307/2844878
[2] Powell, R. A., Zimmerman, J. W., & Seaman, D. E. (1997). Ecology and behaviour of North American black bears: home ranges, habitat, and social organization (Vol. 4). Springer Science.
[3] Klinka, D. R., & Reimchen, T. E. (2009). Adaptive coat colour polymorphism in the Kermode bear of coastal British Columbia. Biological Journal of the Linnean Society, 98(3), 479-488.
[4] Caro, T., & Mallarino, R. (2020). Coloration in Mammals. Trends in Ecology & Evolution, 35(4), 357–366. doi: 10.1016/j.tree.2019.12.008
[5] Moore, J. A., Draheim, H. M., Etter, D., Winterstein, S., & Scribner, K. T. (2014). Application of Large-Scale Parentage Analysis for Investigating Natal Dispersal in Highly Vagile Vertebrates: A Case Study of American Black Bears (Ursus americanus). PLOS ONE, 9(3), e91168. https://doi.org/10.1371/journal.pone.0091168
[6] Garshelis, D. & Steinmetz, R. 2020. Ursus thibetanus (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2020: e.T22824A166528664. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T22824A166528664.en. Accessed on 18 August 2022.
[Edited by Meredith Lutz and Jacob Johnson, all photos by Alice Michel]
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