What do we know about the Monarch butterflys migration?
We know that millions of Monarchs that emerge as naive adults in August and September migrate from central and eastern United States and Canada to overwintering roosts in Mexico. The distances covered by the migrants are often more than 2,000 miles, and, remarkably, the roost sites they seek are located on just a few mountain tops in central Mexico. If we look at a map, we can see that these butterflies end up wintering in places that are south and west of where they started their journey. How do they get there? Clearly, not all of the Monarchs can reach the roost sites by simply flying straight south or southwest. What are the questions? The great Monarch mystery is: How do inexperienced Monarchs from Colorado to New England and the Canadian provinces all find the same traditional roosts in Mexico each year? What environmental information is used by Monarchs to guide their migratory flights? Do they use the sun as a compass, are they guided by the earth’s magnetic field, do they follo
