Each fall the monarch butterfly travels thousands of miles to spend the winter in the forests on 12 mountaintops in central Mexico. The monarch migration is the most spectacular two-way migration carried out by an insect.
The forests provide unique microclimatic conditions that allow monarchs to survive the winter. Forest degradation is putting this amazing migration in peril.
The abundance of monarchs shows a discouraging downward trend over the past 20+ years. Click on the graph to enlarge and on this link to read how the numbers were obtained.