A mother grizzly and her cub walk through a meadow in Yellowstone National Park. | Photo by Will Powers / SOPA Images / LightRocket via Getty Images
Yellowstone’s grizzly bears have managed to stay just as fat over the years regardless of growing environmental stressors, according to new research. Fat is life for a bear; it needs lots of fat to make it through months-long winter hibernation and have healthy cubs. That’s why scientists monitoring the bears in and around Yellowstone National Park were happy to find plump grizzlies despite some of their major food sources dwindling.
“We were kind of surprised,” says Frank van Manen, an ecologist with the US Geological Survey who leads the Interagency Grizzly Bear Study Team. Looking back on data collected on the park’s bears over 20 years, van Manen and his colleagues found that body fat levels had stayed roughly the same for bears…
