BA recent article on a study of monarch butterflies raised in captivity has a lot of people aflutter. On June 24, National Public Radio shared a story on social media of a graduate student at the University of Chicago who ordered monarchs from a breeder and “made an accidental discovery: the butterflies had likely lost the ability to migrate” [1].
The article continued to report that the student chose a breeder that supplies butterflies for educational settings with the goal of speeding up her experiments. They discovered the breeder’s butterflies had rounder, smaller top wings similar to non-migratory butterflies. When they were put in a flight simulator, unlike the wild North American butterflies they’d been raised alongside, they did not orient south. They concluded the captive-bred butterflies were unlikely to migrate. The findings were published in the Proceedings of the National Academy of Sciences (PNAS) journal [2].
Beaver Creak Reserve has been raising monarchs for nearly 10 years. Each year we train more and more community members how to raise monarchs in their own home to help increase the population. Because of this article, many people have questioned whether their own citizen efforts are potentially producing non-migrating monarchs, so we asked our own specialist. “I think it’s quite likely that some captive-raised monarchs may lose their ability to migrate,” explained Jim Schwiebert. “Especially those that are sourced from places in the southern United States, Florida in particular, where the majority of the monarch ranchers exist.” Monarchs are able to overwinter in Florida and even parts of southern California due to the year-round mild climate.
Schwiebert continued, “I think our records at Beaver Creek show pretty strongly that our monarchs do make it to Mexico, considering we’ve had 10 tag returns in the 20 years that we’ve been tagging. So I don’t think this article is directed at home hobbyists, or small-scale operations like Beaver Creek, who only raise native monarchs from wild collected stock and then release them.”
For anyone interested in raising monarchs, it is best to live catch caterpillars or eggs and then release them as soon as the butterflies emerge from their chrysalis. But don’t worry if the Monarchs that emerge in June, July and even Early August don’t immediately head south. Those early generations stay here to breed and then die. It’s the generation of monarchs hatching in mid to late August and September that migrates south.
Brianne Markin, Marketing and Development Coordinator at Beaver Creek Reserve, finds the generational migratory patter of these butterflies simply fascinating. She said, “When we release the later generation of monarchs into our butterfly house ahead of tagging them, they mostly congregate on the southern side of the house. After they are tagged and released, they head south instinctively.”
Monarchs, as well as many other pollinators, have declined in drastic numbers primarily due to the use of pesticides and habitat loss. Monarch butterflies will only lay their eggs on one plant: milkweed. The caterpillars will only eat one plant: milkweed. So if there is no milkweed, there are no monarchs. Use of pesticides in areas along the migration route has also contributed to a population decline. By raising monarchs from either an egg or a caterpillar we can give them a much better chance at surviving to adulthood in order to reproduce.
If you are concerned about the plight of the monarch and want to help, but maybe aren’t ready to make the leap to raising them yourselves, there are still plenty of things you can do.
Plant milkweed.
Plant more milkweek by educating others to plant milkweed or nor mowing ditches or other areas where milkweed grows.
Help Beaver Creek by finding eggs or caterpillars.
If you have milkweed growing on your property, bring it to us to feed our hungry horde. The bonus is that our trained volunteers will often find eggs and caterpillars on it as well!
Donate to Beaver Creek Reserve, Journey North or another organization working to preserve Monarch habitats.
https://www.pnas.org/cgi/doi/10.1073/pnas.1904690116