Newborns measure about 9-12 inches (24-30.5 cm) from nose to base of tail and weigh about 1⅓ lbs (0.6 kg). When they leave the den (where they were born) they weigh in around 22-33 lbs. (10-15 kg.) and by the time they are yearlings, they can weigh 100 to as much as 350 lbs. (45-160 kg.). By two years old (typical time to leave their mom) they may be as large as 400-450 lbs. By adulthood, typically 5 for females and 8 for males, they may be up to 880 (♀) or 1600 (♂) lbs. And measure 4 ft. Tall at the shoulders (that is, on all fours). They can stand up and reach a height of over 10 ft. Tall (the ♂, that is).