Grizzly bears move through landscapes the same way most people do, favoring flat paths on inclines and gentle speeds on sprints, according to remarkable new study on grizzly bears and the way they live in the great outdoors compares to ours.
The study, which involved wild and captive bears, a specialized treadmill, apple slices, and GPS trackers, expands our understanding of how a natural drive to save energy shapes animal behavior, including understood ours, and could have implications for health and weight management. The findings also help explain why in the great outdoors, bear and human paths cross so often, providing useful reminders about wilderness planning and everyone’s safety.
Biologists and other scientists have become increasingly interested in how we and other creatures make their way through our environment in recent years. And while some preliminary answers have started to emerge as to why we choose to move and navigate the way we do, the results are not, on the whole, particularly flattering.
A growing body of research suggests that we humans, as a species, are likely to be physically lazy, with a wired inclination to avoid all activity. In a revealing neurological study from 2018, for example, brain scans indicated that volunteers were much more drawn to images of people on chairs and hammocks than of people in motion.
This seemingly innate preference not to move made sense to us once, a long time ago, when hunting and gathering required intense effort and plentiful calories and resting under a tree didn’t. Being inactive is more of a problem now, with food everywhere.
But the extent to which we share this penchant for physical ease with other species, and whether these predilections affect the way we and they travel the world has been unclear.
So, look out for grizzly bears, especially those that live at the Washington State University Bear Center, the nation’s premier grizzly bear research and conservation center. University biologists affiliated with the center study how animals live, eat and interact with humans.
Now, for the new study, which was recently published in the Journal of Experimental Biology, they set out to explore precisely how much energy grizzly bears spend when moving in different ways and how those and comparable numbers might. affect behavior in real life, not just of bears but of us and other animals.
To start with, they built a sturdy enclosure around a treadmill originally built for horses. With modifications, it could rock up to 20%, while still managing the size and weight of a grizzly. On the front of the enclosure, scientists added a power box with a built-in rubber glove.
Then they taught the nine male and female grizzly bears at the center – most residing at the center since birth and sporting names like John, Peeka and Frank – to climb on the treadmill and walk, while quietly accepting slices of hot dogs and apples as a reward. .
“Grizzly bears are very motivated by food,” says Anthony Carnahan, a doctoral student at Washington State University who led the new study.
By measuring changes in the composition of the air in the enclosure, the researchers were able to track each bear’s energy expenditure at varying speeds as it ascended and descended. (The bears have never run on treadmills, due to concerns for their safety.) Using this data, the researchers determined that the most efficient pace for the bears, physiologically – the one at which they used the least. oxygen – was about 2.6 miles per hour.
Finally, scientists gathered available information on the movements of wild bears, using GPS statistics of grizzly bears in Yellowstone National Park, along with map data and comparable figures from previous studies of people and others. animals roaming the natural landscapes.
By comparing the data, scientists found that wild grizzly bears, like us, appear to be born to laze. Researchers expected wild bears to move at their most efficient speed whenever possible, says Carnahan. But in reality, their average pace through Yellowstone was a mile an hour and physiologically inefficient.
They also almost always took the less steep route to get anywhere, even when it required extra time. “They did a lot of side-hilling,” says Carnahan.
Interestingly, these speeds and routes resembled those of people when choosing routes through the wilderness, the researchers noted.
Taken together, the results suggest that the innate urge to avoid exertion plays a bigger role in how all creatures, large and small, behave and generally navigate than we might imagine.
The study does not rule out, however, that grizzly bears, like other bears, can move with sudden and staggering speed and ferocity, when they choose, Carnahan points out. “I saw a bear running through a mountain meadow in six or seven minutes, whereas it took me all afternoon,” he says.
Likewise, the results do not tell us that we humans are doomed to always walk slowly, staying in apartments, but only that it may require mental and physical effort and goal setting to avoid choosing the right ones. easiest routes.
Finally, the study is a strengthening reminder that we share the outdoors with large apex predators who may naturally choose the same routes as we do. You can find helpful information on staying safe in grizzly bear country on the Interagency Grizzly Bear Committee website.