Several types of animal in the Boreal Forest hibernate in order to survive the winter without food. This is an example of... -animal behavior
-fitness
-adaptation
-environmental pressure

This is an example of adaptation and enviromental pressure.

Explanation:

Say you were to move to somewhere where the climate is nothing like you are used to. You would have to adapt to the new climate. The animals in the Boreal forest have to adapt to the climate and know they don't get food in the winter.

The cold weather forces them to do this, honestly. So this is also an example of enviromental pressure bc nature is pressuring them to do this.

Hope this helps