The animal featured on the cover of Information Architecture for the World Wide
Web ,Second Edition,is a polar bear (Ursus maritimus ).Polar bears live primarily on
the icy shores of Greenland and northern North America and Asia.They are very
strong swimmers,and rarely venture far from the water.The largest land carnivore,
male polar bears weigh from 770 to 1400 pounds.Female polar bears are much
smaller,weighing 330 to 550 pounds.The preferred meal of polar bears is ringed
seals and bearded seals.When seals are unavailable they will eat fish,reindeer,birds,
Polar bears are,of course,well adapted to living in the Arctic Circle.Their black skin
is covered in thick,water-repellent,white fur.Adult polar bears are protected from
the cold by a layer of blubber that is more than four inches thick.They are so well
insulated,in fact,that overheating can be a problem.For this reason they move
slowly on land,taking frequent breaks.Their large feet spread out their substantial
weight,allowing them to walk on thin ice surfaces that animals weighing far less
would break through.Because food is available year-round,most polar bears don't
hibernate.Pregnant females are the exception,and the tiny 1 t 1-1/2pound cubs are
born during the hibernation period.
Polar bears have no natural enemies.Their greatest threat comes from hunting,but
in the past 15 years most governments have placed strict limits on the hunting of
polar bears.Their population has more than doubled in that time,and is now esti-
mated to be between 21,000 and 28,000.They are not considered to be endangered.
They are extremely aggressive and dangerous animals.While many bears actively
avoid human contact,polar bears tend to view humans as prey.In encounters
between humans and polar bears,the bear almost always wins.