A massive migration across Oklahoma, Arkansas, and Kansas this week resulted in the most spectacular sightings of the season. Most miraculous was the mile of clustering monarchs discovered on Sunday in a sunflower field in Kansas. Just think…It’s the first week of October and migrating monarchs are still being spotted across the north.

Unlike most other insects in temperate climates, monarch butterflies cannot survive a long cold winter. Every fall, North American monarchs fly south to spend the winter at roosting sites. Monarchs are the only butterflies to make such a long, two-way migration, flying up to 3000 miles in the fall to reach their winter destination. Amazingly, they fly in masses to the same winter roosts, often to the exact same trees. Their migration is more the type we expect from birds or whales than insects. However, unlike birds and whales, individuals only make the round-trip once. It is their children’s grandchildren that return south the following fall.

To test their ability to reorient themselves, Dr. Taylor has moved butterflies from Kansas to Washington, D.C. If he releases them right away, he said, they take off due south, as they would have where they were. But if he keeps them for a few days in mesh cages so they can see the sun rise and set, “they reset their compass heading,” he said. “The question is: How?”