Monarch Butterflies

The climate of Central Mexico’s fir forests is just right for monarchs: not cold enough for the butterflies to freeze, but cold enough to keep their systems dormant until spring. However, global warming is causing more cool-weather precipitation in these areas, which is bad news for the butterflies since they can freeze to death if temperatures drop too low. Increased cool weather precipitation also spells trouble for monarchs because their wings must remain dry to stay warm—when rain follows a cold front, butterfly mortality can soar

The striking monarch butterfly is tougher than it looks. This tiny flier undertakes an incredible 2,000 mile journey every winter in search of a few specific mountaintops in the fir forests of Central Mexico. Amazingly, the epic migration to and from the fir forests spans the life of three to four generations of butterfly, meaning no single individual ever makes the entire journey. Yet the species as a whole instinctually knows where to find these isolated mountaintops year after year.