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Keeping track of monarchs

Butterflies’ population declining

By Greg Seubert


To some people, it’s an unsightly mess of weeds blocking the view of a lake.

To a caterpillar that will soon become a monarch butterfly, however, it’s home.

Hartman Creek State Park naturalist Lisa Bey is working with the Monarch Larva Monitoring Project to monitor monarchs – including their eggs and caterpillars – in the park this summer.

Jim Motzer and Charles Fowler of Chicago, who were camping in the park’s campground, and Bob Precourt of Stevens Point showed up June 28 at the park’s Allen Lake Picnic Area to find out more about the program.

“We were really intrigued by the butterfly larva count project and thought we would learn something,” Motzer said. “We’ve been on the lookout for monarchs. We know that the population has been declining and we wanted to learn what we could do to try to restore the population. It’s a great feeling to volunteer for an activity like this to help restore the habitat and the population of the monarch butterfly.”

Monitoring milkweed

Bob Precourt of Stevens Point looks for caterpillar eggs and caterpillars on milkweed plants in Hartman Creek State Park’s Allen Lake Picnic Area.
Greg Seubert Photo

Bey, Motzer, Fowler and Precourt examined a small patch of milkweed next to the Allen Lake fishing pier.

“Our count was pretty low today,” Bey said. “We only saw three caterpillars and they were all older caterpillars, which makes me think that they’re probably at the point where they’re going to start pupating soon and we’ll get our next batch (of caterpillars) coming in shortly.

“We did see a lot more caterpillars the first two weeks we did this,” she said. “We did have a big storm last night, so that might have affected some of our numbers today.”

Bey’s plan is to monitor the same area of milkweed all summer.

“When you’re collecting scientific data, you want to have control,” she said. “Our control is that we are doing a very specific site and we are counting the same plants every week. Next summer, if I get more volunteers, we have milkweed all over the park in a lot of accessible spots. You don’t have to go into the tick-infested areas to see it. If people want to come out and do different areas of the park, that would be great. We could even start this year.”

Bey enters the information the volunteers collect on Monarch Larva Monitoring Project website.

“I will enter all of the data we collect all summer long,” she said. “There are people all over the country collecting this data so they can get a really good idea of what’s happening with the butterflies. There are even people in Mexico and Canada doing this as well. We’re going to go all the way into September. I’m going to do it until I don’t see any more butterflies and know for sure that they’ve migrated.”

Population in decline

While common in Wisconsin, monarch populations have dropped by more than 80 percent over the last 20 years in the Eastern United States.

Several factors are behind the decline, according to Bey.

“Habitat loss is probably the biggest one, with people not realizing that the monarchs absolutely need the milkweed,” she said. “It’s an unfortunate name with weed in it, so a lot of people don’t realize that it’s such a beneficial plant. They’ve really lost a lot of their habitat on the pathway where they’re migrating.”

Monarchs migrate each fall to the Sierra Madre mountains of central Mexico. They head north in spring, breed along the way and then die. Their offspring return to their northern starting point, where they lay their eggs on milkweed plants.

“I don’t know much about the butterflies, but we’ve certainly been monitoring their decline,” Motzer said. “One thing we’ve learned here is that most of them live for only one month and the last cycle, they’re the ones that last for nine months and make that journey to Mexico. They’re such a beautiful and small insect and it’s just incredible that they make that kind of journey.”

How to help

Bey said people can help the monarch population.

“Plant milkweed because the monarchs absolutely need it,” she said. “It is the only plant that they will lay their eggs on, it’s the only plant their caterpillars can eat. Just because it might not be the plant you want or planted there, that does not mean it’s not an important plant. Every plant has its purpose.”

Other plans can also help monarchs, she said.

“Native is the key,” she said. “You want to make sure they’re native plants that the adult butterflies can use for a nectar source because that’s their fuel to get them to make the next generation and to make that fall and spring migration.”

Anyone interested in the project can contact Bey at the park office at 715-258-2372 or at [email protected].

“None of this work would get done without volunteers,” she said. “There are only so many paid scientists out there and they would not be able to really know what is happening without all these amazing volunteers.

“The goal is to get more people out interacting and being a part of citizen science and also to get the word out about the plight of monarchs and other pollinators,” she added. “Hopefully, I can get as many people interested in it so they do their part to help these animals.”

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