As the weather warms, it's time for Monarch butterflies to make their way through our region. But they're not around in the numbers they used to be - not by a long shot. By some estimates Monarch populations have dropped by 90-percent over the past twenty years.
In the first of our two-part series from WYEP in Pittsburgh, The Allegheny Front's Julie Grant looks at what's driving the declining numbers of these iconic butterflies.
Jerry Wiedman is counting butterflies. He's a retired chemist, and today he's holding a clipboard, and a butterfly net with a pole almost as tall as he is. We're walking around a park that overlooks Lake Erie in northeast Ohio.
"That one's pretty."
"Yeah, that's a cabbage white."
This isn't just a casual walk. This path through meadows and woods is what's called a butterfly transect. It's about one and a half miles, and is split into sections. Wiedman and others set it up. During butterfly season, he or someone else walks it weekly.
"And we count butterflies within 7.5 feet on either side of us."
As we walk through each section, he jots down how many butterflies and what species we've seen.
"There's your red admiral, see him?"
Wiedman has been fascinated with butterflies since he was a kid.
For many young people, Monarch butterflies are the first to get their attention. Their large, orange and black wings are easy to spot. And their migration story is a mystery of nature. Each spring, these tiny, fluttering creatures fly thousands of miles. They leave their winter homes in forests high in the mountains of Mexico. The females lay eggs on milkweed plants in the southern U.S. Most Monarchs live only a few weeks. So the new butterflies continue the journey started by their parents. It can take five generations to complete one migration to Canada.
Some years, Wiedman has personally counted hundreds of Monarchs migrating through Ohio.
But that's changed.
"We don't get the the numbers we did in the late 90s or early 2000."
His counts show fluctuations in the Monarch population, but it's a downward trend.
It's the same story around the country.
"Hi, I'm Chip Taylor, director of Monarch Watch at the University of Kansas."
Taylor says Monarch numbers started to plummet in the early 2000s. That's when new farming technology - known as Roundup Ready seeds - became popular. Farmers used to spend long hours tilling the soil, or targeting herbicides to kill only the weeds. But with Roundup Ready seeds, they could now spray entire fields with herbicide. The weeds would die, but the crops were fine.
Most farmers loved it. Fields looked cleaner, with less work. But it killed off the Milkweed, and that's the only food Monarch caterpillars can eat.
"You know, I've got really nice pictures of milkweed growing in corn and soybean fields around the year 2000. Then around 2006 you couldn't find milkweed growing in corn and soybean fields anywhere. I mean it was just about impossible."
Around 2007, President Bush made a push for huge increases in corn-based ethanol and other homegrown sources of energy. With the help of Roundup Ready technology, many farmers planted corn and soy on land that had been fallow, or in conservation. This killed off even more Milkweed.
"And the estimate is that we've lost a 100 million acres of habitat just to the adoption of this particular technology."
According to estimates by the Center for Biological Diversity, Monarch populations have dropped by nearly 1 billion since the mid 1990s. They've petitioned the U.S. Fish and Wildlife Service to protect the Monarch under the Endangered Species Act.
Taylor argues against that…
"I don't think they should be listed as threatened, I think that is counter productive. The value of this petition is that it's caught everybody's attention."
Taylor says regulation could set up conflicts between farmers and the federal government.
Still, he sees a need to restore tens of thousands of acres of habitat for the butterflies. He says that's already starting to happen, with many people planting milkweed in their home gardens and teaching children about it in school.
For The Allegheny Front, I'm Julie Grant.
Tomorrow, part two of our series on Monarch butterflies looks at efforts to help save them. To learn more about the decline of the Monarch butterfly population and The Allegheny Front, CLICK HERE.