Fact: "... the walrus is sometimes 'caught napping.' Occasionally, when the weather is intensely cold, the hole through which he crawls upon the ice gets frozen over so solidly that, on waking, he finds it beyond even his enormous power to break it. In this extremity there is no alternative but to go to sleep again, and-die! which he does as comfortably as he can. The Polar bears, however, are quick to smell him out, and assembling round his carcass for a feast, they dispose of him, body and bones, without ceremony."
Source: The World of Ice, by Robert Michael Ballantyne.
How far can polar bears swim?
Polar Bear Tracks
Image Source: Mike Dunn, NOAA Photo Library.
Fact: Female polar bears usually give birth to five litters during their lifespan. Though polar bears, Ursus maritimus, are not on the endangered species list (as yet), the fact they have a reproduction rate that is one of the slowest among mammals, makes it all the more important to protect these magnificent creatures before it's too late.
Source: Howstuffworks "Polar Bear Reproduction," by Julia Layton