Do brown bears hibernate in winter?

In the temperate zone, winter poses a serious challenge for animals. Partly due to the cold, but even more so because in winter, the amount of accessible food is much more limited for many animals. Indeed, it is during winter when more energy is needed for the body to counterbalance the low temperature of the external environment with adequate heat production.

In the animal kingdom, over the course of millions of years, several solutions have been developed to handle the problem. Some animals, primarily migratory birds, move to warmer climates. Others accumulate significant reserves from various foods for times of scarcity. Others, on the other hand, fatten themselves up, so ultimately, they also create reserves, but in the form of a layer of fat accumulated under the skin. Of course, having reserves is not enough, one must also economize: hibernation essentially serves this purpose. The animal in a state of rest consumes less energy, and this allows the reserves to last until the next spring.

The classic winter sleep is actually hibernation. The animal’s metabolism slows down so much, and operates so “economically” that even the body temperature decreases by several tens of degrees Celsius, barely remaining above freezing point. We can observe exactly this in the case of bats, mice, and hedgehogs.

The situation is somewhat different with brown bears, which is interesting because when it comes to hibernation, most people think of bears. However, the brown bears’ winter sleep is not true hibernation. Their body temperature only decreases slightly, and of course their sleep is not that deep, but with this they are much less active, they sleep a lot more, and essentially, they do not eat at all during the hibernation period.
Of course, the brown bears’ propensity for hibernation varies by area. There are already regions where, due to climate change, increasingly warmer winters are prompting bears to be much more active during the winter period.

It is certain that our two brown bears, Csángó and Hargita, will not hibernate this winter. After all, the essence of the winter dormant period is to conserve energy due to the scarcity of food. However, we provide adequate feed for the brown bears in the zoo even during the winter period, so they have no reason to hibernate. This means that the audience will be able to see them even during the winter season.