By Chris Healy

It is mid-August and the appetite of the Sierra Nevada black bear is about to take a dramatic swing upward. Motivated by signals from nature known as zeitgebers, the bears will spectacularly increase their daily caloric intake from 3,000 calories per day to upwards of 25,000 calories per day.

This physiological wonder is known as hyperphagia. Nature’s dinner bell is ringing.

“Hyperphagia is a period where bears eat as much as they possibly can so they can put on as much fat as possible to carry them through winter hibernation,” said biologist Carl Lackey. “Nothing much gets in the bear’s way when they are this hungry.”

Bears in Tahoe sometimes like to forage for people food. Photo/Janice Eastburn

Armed with that big appetite and motivated by zeitbegers like decreased daily sunlight and cooler morning temperatures, the bears will search far and wide in the hunt for food. Those 25,000 calories are the human equivalent of eating about 50 cheeseburgers per day over the next three months.

The moon will be full or nearly full for 10 days beginning this weekend (Aug. 17-24) just at the time that the bears begin to ratchet up their appetites.

“They will eat up to 20 hours per day during a full moon period as they pile on the fat,” stressed Lackey. “People living in bear country should not be tempting these already hungry bears with easy access to garbage, bird feeders, bowls of pet food or ripened fruit falling from trees.”

Areas most at risk of attracting bears by granting access to garbage and other attractants are the Lake Tahoe Basin (especially Incline Village), west Carson City and the foothill areas of Douglas and Washoe counties.

Nevada has had two dry winters in a row and the natural foods that the bears desire are not in abundance in the wild lands.

“Plants that create nuts and berries like manzanita, squirrel tail, snowbush, desert peach and rosehips are highly desired but not always abundant in dry years,” Lackey said. “It will be a busy next three months in bear country.”

People needing to report nuisance bear activity can call the NDOW’s Bear Hotline telephone number at (775) 688.2327. For information on living with bears, go online.

Chris Healy works for the Nevada Department of Wildlife.