What are two changes during the fall that cause many animals to prepare for winter?

Answer 1

Animals grow heavier, denser coats of fur/hair with guard hairs and a soft, downy undercoat in replace of their much lighter, summer coats. Animals will also do either of the following:

• Stock up on food supplies (squirrels, chipmunks, picas, ground squirrels, beavers, muskrats, etc.)
• Eat high-energy foods to put more fat on their bodies (winter is a time of fasting for most animals) (i.e., bears, all ungulates)
• Begin to migrate south (i.e., many species of birds do this) or down into valleys where more food will be available and the snow won't be so deep to trudge through
• Get their bodies prepared for hibernation or find places to hibernate in (i.e., frogs and turtles bury themselves in mud and allow their bodies to cool to the point of freezing and their hearts to slow down to almost 1 or 2 beats per minute, if that.)

The list goes on, as it really depends on the individual animal and their behavioural adaptations to prepare for the hard times of winter.

Answer 2

Many animals wait for the cold and the sudden lack of food in its environment.