Volunteers Help Scientists Track Michigan's Butterflies
More than one species of butterfly has seen its numbers drop – in some cases plummet – in recent years. The monarch is doing better than some.
But scientists who track it say it’s been in decline for more than a decade.
They want to keep a close eye on it, which means they need to know about how many are out there, and where. And that’s where trained volunteers – citizen scientists – can offer a lot of help. Together with gardeners, they’re making important contributions to butterfly conservation in southwest Michigan.
Ilse Gebhard is well known in the Kalamazoo area for her work to preserve the monarch. On a morning in late May, she stands by a table of seedlings in her yard in Alamo Township.
“Those are butterfly weeds,” Gebhard says. “This - pink flowers – that’s orange flowers – and those are also the swamp milkweed.”
Some stand a foot high. Others barely reach the top of the pot.
“This is what they look like when they’re bigger, and then here we have common milkweed in these little pots.”
Milkweed happens to be the only plant the caterpillar of the monarch butterfly will eat. And that’s why Gebhard grows it. She says monarchs have fascinated her since a day when she was chopping down invasive honeysuckle bushes.
“I found a Monarch chrysalis on one. So I brought it inside and out came the butterfly and I was just hooked,” she says.
The last fifteen years have been tough on Midwestern monarchs. They’ve lost food and habitat because of an agricultural trend that began in the late 1990s.
Farmers started to grow crops that, thanks to genetic engineering, could tolerate herbicides like Roundup. But Milkweed – like most plants – is no match for Roundup.
Gebhard says growers are squeezing in corn crops even on “marginal land” to meet the demand for ethanol.
And people who cultivate short green grass don’t help either, she says.
“They move out in the country and they buy five or ten acres and they put it into lawn, and lawn is absolutely – doesn’t do anything for any insects,” she says.
Conservation biologist Ashley Anne Wick says last year’s figures on the monarchs that migrate from the U.S. to Mexico for the winter were particularly dismal.
Wick studies butterflies at the Kalamazoo Nature Center. Today she’s at the Center’s field station in Alamo Township. She says last year, biologists recorded the “lowest number ever” of migrating monarchs.
It was a big drop “even from the previous years where we had said ‘this is the lowest number ever,” she says.
“And we keep having these lowest number evers.”
Wick says the volunteers she trains to count butterflies and record the data make a “huge contribution” to her field.
“The tagline for citizen science is ‘no PhD, no problem.’ You don’t have to be an expert to help us collect valuable scientific data,” she says.
This weekend she’ll finish a course for volunteers she’s instructing in a technique called the Pollard method. Her students learn to note all butterflies they observe within five meters on either side of a set path.
“We set them up with a route that is one to three miles long, and they just walk it slowly six times throughout the year and count the butterflies that they see,” she says.
The idea is to monitor common species to make sure their populations are holding up – before they pass a critical point.
And that’s why Gebhard, who focuses on monarchs, will also be leading a workshop this weekend, at the Kellogg Bird Sanctuary.
She’ll teach volunteers a method for tracking larval monarchs – that is, eggs and caterpillars.
“They check the milkweed in that site once a week for eggs and larva that they find. And then they enter the data online on the database so that it can be analyzed,” she says.
It will be analyzed by scientists at the University of Minnesota. They run the Monarch Larva Monitoring Project, which gathers input from volunteers around the country.
Gebhard says the monarch, with its bright colors and recognizable pattern, makes an excellent “showcase insect” for naturalists.
“A lot of people know what it looks like. They don’t know what all the little other insects are. So you can use the monarch as an educational tool,” she says.
“Because whatever you do for the monarch is going to be good for other pollinators and all the other insects.”
Wick says once a butterfly’s numbers are so low it’s endangered, you don’t want to show people where they are, because you could further disturb them. And it’s harder to judge their condition.
“It gets to the point where we can’t really do much investigation into looking into its decline when there’s not really enough left to study,” she says.
Wick studies two butterflies whose numbers have dropped much further than the monarch’s. Both have spent more than 20 years on the federal endangered species list. One is the Karner Blue, which, like the monarch, also saw its worst numbers ever last year. The other is the Mitchell’s satyr. That’s satyr as in the half-man, half-beast of Greek mythology.
“The satyrs are these little brown butterflies. Some people would call them drab but I like to call them chocolaty brown,” she says.
Several clusters of Mitchell’s Satyrs used to live in Kalamazoo County. But they’ve disappeared. Wick is working with several groups and the U.S. Fish and Wildlife Service on plans to reintroduce them. She says they’re “up against a lot” when it comes to bringing back endangered butterflies.
But she adds that since moving to Kalamazoo a little more than a year ago, she’s been impressed with how many people want to grow native plant species.
At her property, Ilse Gebhard has been doing exactly that – killing off patches of lawn with mulch and replacing it with things like milkweed and prairie grasses.
“You want to plant native plants because that attracts the native insects. And they develop together over the years. I have one butterfly bush which is not native and nothing eats it,” she says.
Gebhard will give away most of the milkweed plants she’s raised to people who want to attract monarchs.