Now that September has arrived it is hard not to turn our thoughts toward fall and migration. Invariably we associate migration with birds. However, the plight of the monarch has heightened our interest in the migration of insects such as the monarch butterfly.
Each fall these amazing insects make their way south to their winter home in Mexico. While this is truly an amazing fete, we know very little about how these butterflies accomplish this seemingly impossible task. Recently the results of research conducted by Samantha Knight of the Nature Conservancy of Canada and others filled in another piece of the jigsaw puzzle of monarch migration.
The research team captured and placed tiny transmitters weighing only 300 milligrams on 43 monarch captured near the Canadian shore of Lake Huron. The devices were mounted on the insects in an attempt to track their southbound migration. Fortunately, the biologists were able to retrieve data from six of these butterflies. One of the most interesting findings was one of the monarchs flew 89 miles in a single day. They were also able to determine the monarchs winged their way south at a speed on 7.5 miles per hour. Knight later stated, “[It] was a lot faster than anyone had ever really anticipated.” She went on to comment, “They could likely go even faster without the heavy tags on them.”
The biologists also learned the butterflies flew faster when they were pushed along by a tailwind. This was demonstrated by one butterfly that was clocked flying at a bit under 18.5 miles per hour with the aid of a tailwind.
It was also discovered that monarchs flew faster in warm weather. However, the butterflies were not able to fly until the temperature reached 50˚F and flight speed dropped when the air temperature reached 73˚F.
It is definitely true the more we learn about these stunning insects the more we realize why they are so special.