How and Why Do Fat Bears Get So Fat?

Fat Bear Week started on Wednesday, October 4, and we can’t wait to find out which bear will be crowned the Fattest Bear by the public. The National Park Service says that Fat Bear Week celebrates the success and survival of the brown bear population. But how do fat bears get so fat anyway?

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Brown bears must bulk up before they go into torpor, a state of sleepiness and inactivity, in late November. The grizzly bear’s bulking period is known as hyperphagia, and this helps ensure they can survive the five to seven months they spend in torpor. According to Yellowstone Bear World, Bears will gain three pounds a day before the start of torpor, and they can feed up to 20 hours a day. 

This means that bears need to eat upwards of 20,000 calories a day. 

In 2021, Colorado Parks and Wildlife, North East Region tweeted this photo out to help the public better understand what it would look like for a human to eat 20,000 calories a day. 

Bears go into hyperphagia in the middle of summer into early fall to pack on the pounds so they have enough stored energy to survive the long winter.

Source: https://outdoors.com/how-and-why-do-fat-bears-get-so-fat/