**6. Climate change adaptation in animals**

Adaptive evolution of phenotypes to climate change has been the subject of several investigations [26, 39].

Animals react to climate change in three ways: to move, to adapt, or to die. Moving to a new territory is not always a simple solution and can create new challenges (e.g., interaction with unfamiliar species and more competition for food).

Some animals can adapt to changing conditions. An interesting example of adaptation to climate change is the case of polar bears. With the change in climate, polar bears who usually used seal pubs and other marine mammals as food, have started hunting animals available on land (e.g., snow geese and caribou). However, there is no proof that the change in diet can support the polar bear population in the long run. Another example of adaptation to climate change is with migrating birds. As spring arrives earlier, insects emerge earlier. Some migrating birds are laying their eggs earlier to match insect availability for their young.
