In this deleted scene from North America, starving bison struggle to survive when winter sets in, and a bison calf succumbs to the elements.

A chipmunk gathers nuts for the winter, amassing about 6,000 of them by end of fall. But he needs to keep an eye out for pickpockets...

An old bighorn sheep and a young contender collide head-on in a fight for mating rights. Their thick, shock-absorbing skulls can withstand 800 pounds of force.

An acorn woodpecker guards its carefully stashed nuts from a very hungry and persistent squirrel.

The adorable collared pika is as cute and cuddly as they come, that is unless you're a bird that's blown off course in the Alaskan wilderness...

Go behind the scenes of the alligator sequences with North America Cinematographer Sophie Darlington and Assistant Producer Ben Wallis.

A team of Harris hawks work together to chase down a cottontail rabbit in the Sonoran Desert, weaving in and out of cacti as they home in on their prey.

In Mexico's Gran Desierto de Altar desert, a fringe-toed lizard outruns a sidewinder rattlesnake.

This one-pound bunny, called a pygmy rabbit, gets into a high-speed chase with a long-tailed weasel.

North America's incredible sights and sounds come to life in our split-second highlight reel.

The amazing sights and sounds of North America's savage coasts come to life in our split-second highlights real.

The MythBusters take on a scene from the '80s classic Real Genius: What happens when you fill a house with popcorn ... then make it all pop (with explosives, in this case)?

The MythBusters take on a scene from the '80s classic Real Genius: What happens when you fill a house with popcorn ... then make it all pop (with explosives, in this case)?

During the MythBusters Comic Con 2009 panel, Adam Savage addresses why the team won't debunk myths like Big Foot, UFOs and crop circles.

The MythBusters take on a scene from the '80s classic Real Genius: What happens when you fill a house with popcorn ... then make it all pop (with explosives, in this case)?

The MythBusters take on a scene from the '80s classic Real Genius: What happens when you fill a house with popcorn ... then make it all pop (with explosives, in this case)?