Spring doesn't burst into full bloom in the regions where bears make their homes. It trickles slowly to life, offering scant relief for bears emerging from hibernation. In many ways, spring is the hardest season of the year for bears — particularly bear cubs. They emerge from their dens to a world that they must share with juvenile and adult bears that have also just surfaced after a long and depleting sleep. They are hungry, but the land is not yet offering an abundance of nourishment.
Adult and juvenile bears will sometimes scavenge the carcasses of bighorn sheep or mule deer that succumbed to avalanches or the cold. But the opportunistic bears do not discriminate when feeling the sharp pangs of hunger, and it is not uncommon for them to turn to cannibalism during the lean spring months.
The cubs are still small — no more than 12 pounds. They are already attractive prey for wolves, lions, lynx, bobcats and even golden eagles. But these predators pose less of a concern than other bears. Some consider infanticide — the killing of one's own young — to be the most common cause of mortality in cubs. This cannibalistic behavior may the result of hunger alone, or it may be related to the ever important objective of reproductive success.
Regardless of the motives, one-third of the cubs born this year will never live to see their first birthday. In addition to those felled by disease and starvation, many will likely perish at the claws of hungry members of their own species.