Adult males can measure more than nine feet in length and weigh between 770 and 1,430 pounds.The fur is 95 percent efficient in converting ultra-violet sun rays into usable heat. Its transparent hairs have a hollow inner core which scatters ultra-violet light by some unknown mechanism, converting it into heat when it reaches the bear's black skin. Surprisingly, the fur has no white pigment; it is the reflection of the sun that causes the fur to appear white.
