Monarch butterflies are known for their bi-annual migrations. Traveling from Mexico all the way to Canada, this species of butterflies is showing up in Michigan sooner than anticipated, but in lower numbers than previous years.
The monarch butterfly migration is tracked through an interactive map on Journey North, maps.jorneynorth.org, a website for the public and for researchers to track wildlife migrations. According to the map, monarch sightings began in southeast Michigan as early as April.
Now in June, monarchs have been reported as far north as Sault Saint Marie. Northern Michigan counties such as Alcona, Presque Isle, and Crawford have already reported sightings.
David Mota-Sanchez is an entomology professor at Michigan State University. He has started a monarch conservation program in Mexico that he also works on in Michigan. He said temperature changes and wind directions influence the monarch’s migration times, and that their behavior is identical in both Mexico and Michigan.
Mota-Sanchez said he uses the Journey North map in his own research and found that this year’s migration to Michigan is occurring a little sooner than usual, but that butterfly numbers are lower.
“If you check the map, you’ll see that (the numbers are) a little bit lower than last year,” he said. “But you have to remember we’re only in the beginning of June. It’s lower this time of year.”
Mota-Sanchez said the change could be minor, as the butterflies tend to make more of an appearance in late June and July. He said their migration times have gotten unpredictable as the climate changes, and research suggests this could cause the monarchs to return to Michigan even earlier in the future.
“We’re in an unpredictable situation because of the weather,” he said. “Maybe they will continue to return early in the U.S.”
This sooner migration has been noticed by butterfly monitors as well. Ronda Spink is the coordinator for the Michigan Butterfly Network, a network of citizen scientists who monitor butterfly populations across the state. Spink said she monitors butterflies for work and for pleasure.
“They’re my solitude and my happy place,” she said. “I would much rather be out chasing butterflies than pretty much doing anything else.”
Spink said she spotted her first monarch butterfly of the year on May 12. She said this sighting was earlier than last year’s, which was May 22. Spink said the network has been getting reports from across the state, though some are few and far between.
“We are seeing adults, but there’s not very many,” she said. “It’ll pick up, but I think this year may be a slower year for them.”
Additionally, Spink said the number of all butterflies has been decreasing in the state. She said the rates have been “slowly going downhill” for the last two years.
“But that’s the way it is with butterflies,” she said. “It’s up and down, and it varies every single year. That’s the exciting part about it.”
For those who have not spotted a monarch butterfly yet, both Mota-Sanchez and Spink said there is still time. May is breeding season for monarchs, and they both said sightings will be more common as the summer months progress.
