Painted Lady Migration

November isn’t exactly butterfly weather, but the topic today is painted lady butterflies.

Most everyone is familiar with the painted lady because they are among the most widely distributed butterflies in the world. They are two to maybe three inches long with the upperside of the wings an orange-brown with dark bases. The forewings are black with a white bar on the leading edge, and the apex black. On the hindwings are four small submarginal eyespots. They look like a smaller and more mottled form of a monarch with black at the outer corners of the forewing, which contains some white spots.

Although we see painted ladies during the summer, they likely do not survive the winters here in North Dakota. Similar to that of monarch butterflies, the painted lady is known to come northward during the summer months, perhaps all the way from Mexico. Population eruptions in Mexico are known to occasionally result in large concentrations of painted ladies migrating northward. These migrating painted ladies may be observed in some areas in extremely large numbers over several days.

Perhaps like you I have occasionally watched butterflies such as monarchs or painted ladies flying in the summer breezes and wondered how they can possibly migrate that long a distance with the often strong and variable winds here in North Dakota as well as elsewhere.

Painted ladies are also native to Europe, and recent research on their migrations between northern Africa and Europe has led to some interesting discoveries. One study was recently summarized in “Science NOW” on the website of the American Association for the Advancement of Science. Using radar to help track insect movements, the researchers discovered that painted ladies would fly upward to around 500 meters or 1600 feet to ride fast moving winds. This allowed them to travel more than 30 miles per hour, or double their normal speed. That would also save them a lot of energy!

To my knowledge this phenomenon has not been documented in North America, but the painted lady and other North American butterflies may also fly at higher elevations to take advantage of air currents in their migration. Who knows? But next summer when temperatures are warm and the butterflies are dancing in the North Dakota breeze, those delicate aviators may have just had the ride of their lives.

Chuck Lura

Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Minot State University-Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.