Every season brings challenges to the survival and procreation of bears.

As spring temperatures begin to inch upward, their subcutaneous fat is depleted and they feel a pang of hunger. The first plants are out and it’s time to leave the warm den, despite the occasional show flakes drifting across the still chilly air. But the den is so cozy that after a day’s foraging for food, the bear comes back for a good night’s sleep in the first week or two.

In April, all they’ve got for food are last year’s wild apples, dog roses and ants, so a bear has to work hard to earn its keep.

In May it’s already warmer, nicer and there is plenty more to eat. However, this is also the season in which hikers venture out into the mountains, so bears need to make themselves scarce. To stay out of sight, they set up temporary lairs, using young twigs for bedding and cover.

As summer sets in, there comes the mating season.

In August, its wild berry season, with bilberries, raspberries and other forest fruits providing bears with a delicious and satisfying meal. The woods would be a bear paradise - if it weren’t for humans who often beat them to the prize and strip the bushes bare.

Come autumn, the bear is heavier than ever and there are still plenty of wild fruits around. Only in October, with food growing scarcer, are bears forced to roam longer distances for their meal. With the first snow, they start looking for a den, where they will lie down and hibernate without food until next spring.

Video: