Did you know that monarch butterflies, migrating north from Mexico, live only 2-6 weeks? As they emerge from overwintering in Mexico, the monarchs make their way north, as far as Canada, laying eggs along the way. There will be 3-4 generations of monarchs, each subsequent generation making it a little farther north. The last generation, however, known as the Methuselah generation, can live up to 8 or 9 months. That is because that generation not only flies back to Mexico, arriving in early November, but will overwinter until March—at which time they will begin to journey north to begin the reproductive cycle all over again.
Monarchs are probably our best known and loved butterflies. Not only have they captured the interest of professional scientists who are still learning about their amazing migratory feats, but also of “community scientists” who are helping to raise, monitor, and tag them. Interest in these butterflies continues to grow as their population declines. In 2022 the International Union for the Conservation of Nature (IUCN) classified monarch butterflies as endangered. Below is a graph, courtesy of the Monarchwatch.org, that displays the number of hectares in Mexico, by year, populated by overwintering monarchs. (A hectare is equal to about 2.5 acres.) The graph clearly shows a downward population trend.