Extras

Video thumbnail: Nature Killer Whales Attack Pod of Narwhal

Nature

Killer Whales Attack Pod of Narwhal

Killer whales pin down an entire pod of narwhal in shallow water.

Killer Whales Attack Pod of Narwhal

Video thumbnail: Nature Invasion of the Killer Whales | Preview

Nature

Invasion of the Killer Whales | Preview

Airs Wednesday, November 19, 2014 at 8:00 p.m. ET/PT. Check your local listings.

Invasion of the Killer Whales | Preview

Video thumbnail: Nature Polar Bears Try to Catch Salmon

Nature

Polar Bears Try to Catch Salmon

Polar bears are forced to try their luck hunting salmon as arctic ice sheets dissappear.

Polar Bears Try to Catch Salmon