Grizzly (Ursus arctos)
Known as the second largest terrestrial carnivore in North America. The average male
weighs 250 to 350 kilograms, females half that.
A full life for a grizzly in the wild is 25 years.Females have their first litter
when they are between five and seven and their last at 20.
The ideal meal is a bellyful of berries, which are critical for building fat deposits
to carry grizzlies through the denning period. In spring, they will prey on newborn
moose, deer, elk and caribou, but 80 to 90 percent of their overall diet is vegetation.
Slumber time begins for females in mid-November, while males den up to a month later.
They aren’t true hibernators but their body temperature drops and they become
lethargic yet can remain semi-active all winter.
Polar bear (Ursus maritimus)
Known as the largest land carnivore in North America. Adult males can weigh as much
as a small car: 800 kilograms. Females are about half as large.
A full life for a male polar bear is 25 years. Females often live into their late
20s. Both genders become sexually mature at four or five, but many males don’t
breed until eight years old or later.
The ideal meal is a ringed seal, but they will dine on marine mammals as large as
a beluga whale. They eat mainly the fat and skin, leaving the meat for scavengers.
Slumber time b egins in mid-October, when pregnant females den. Like grizzlies, they
aren’t true hibernators, but if they have not eaten for a week, polar bears are
able to slow down their metabolism to conserve energy.