One event that backyard wildlife enthusiasts look forward to each autumn is the migration of the monarch butterfly. During the fall of the year, these beautiful butterflies stop and feed in our backyards as they make their way to their winter home in Mexico. This epic flight takes a tremendous toll on these gossamer-winged insects.
Ever since it became apparent monarch populations have plummeted to a fraction of what they once were, researchers have been scrambling to learn as much as they can about this fascinating insect. The results of one such study recently conducted by University of Georgia, Odum School of Ecology researchers provide us with answers as to why female monarchs are better fliers.
When the UGA research team compared the wings of male and female monarchs, they discovered some notable differences. It seems the females’ wings are thicker, and somewhat smaller. In addition, their flight muscles are smaller and lighter.
One might think having larger and heavier wing muscles, coupled with thinner and lighter wings would benefit the males. Actually, the reverse is true. The males’ larger and thinner wings are more susceptible to damage. Their wings also forced to bear more weight per square inch than those of the females.
In essence, this means female monarchs are more efficient fliers than males. This, in turn, enhances the chances of the females surviving the autumn migration.
Interesting. I’ve wondered about that for sometime. We’re having about four every day. Even saw a spicebush swallowtail this afternoon. We still have a bed of zinnas and milkweed. Do you think the same ones linger or are they just passing through on their migration route?
Do you still band hummers, Terry?
Thanks for your great articles!
Boy was I surprised to learn this. Never gave it any thought, but, if I had, I would have said that both would have been equal. Love these tidbits.
Interesting. There must be some reasons for the males having thinner wings and stronger muscles though. Maybe it allows them to fly faster and higher when having dominance contests with other males.