For bears, the beginning of the human calendar year has little meaning, ensconced as most are in their dens during the month of January. The true start of the bear's 12-month calendar is the moment when a new bear life begins.
Bear cubs are born in the dark, brutal winter months of January and February, while the weather still rages outside the warmth and safety of the den that pregnant female bears retired to in earlier months. No other North American mammals give birth during this harsh, wintry time of year. Moreover, only the young of marsupials are born in as immature a state as bear cubs.
Cubs enter the world at a fraction of the massive weight they will one day achieve. Black bear cubs weigh a mere 10.5 ounces, while brown bear cubs weigh slightly more. They are covered in only a fine coat of hair, so fine that is almost invisible. Their legs cannot support their weight; their eyes remain sealed shut for the first month. They are in no condition to leave the security of the den, and this is where they will remain until spring begins to make a timid appearance in March or April.