Across the USA monarchs soar and glide in the warm sunshine from March through October (depending where they are born), but what happens in the fall when the brisk cold winds set in and winter looms in the air? Monarchs cannot survive cold winter temperatures of the northern states. So what does a monarch do to keep warm? It MIGRATES south and HIBERNATES! This means that it rests, with a very slow heart rate, just like bears in their hibernation caves. Monarchs east of the Rockies migrate 2500 miles to the Oyamel fir trees of Mexico. Monarchs west of the Rockies migrate to southern California to the eucalyptus trees of Pacific Grove and surrounding areas.
The monarch's flight to Mexico has been compared to the migration habits of birds flying south for the winter. It is the only insect that can fly 2,500 miles to a warmer climate. Their unique wing structure and yearly life cycle makes it possible for the fall generation monarchs to travel thousands of miles (on those amazing little wings) to the warm nesting grounds of Mexico and southern California.