CHESTERFIELD, Mo. – The International Union for Conservation of Nature, or IUCN, listed the Monarch butterfly on their red list as an endangered species for the first time Thursday. 

Each year, Monarch butterflies travel from Canada all the way to Mexico over the course of their migration and back and there are many factors working against their population. 

“They specifically listed the North American migrating population of the Monarch butterflies as being imperiled and endangered, said Tad Yankoski, the Senior Entomologist at The Butterfly House. “Across their entire range, they’re dealing with many different things, ranging from habitat loss to drought or climate change, increased uses of pesticides herbicide.” 

Yankoski said Monarch butterflies have decreased over time.

“Depending on which data you want to look at their number has decreased by as much as 90 percent over the last three or four decades,” said Yankoski. 

One problem is the availability of milkweed. 

“That’s the only food you’ll find in Missouri that they’ll eat and it’s incredibly important for their life cycle. If they don’t have milkweed they can’t survive,” said Yankoski. 

Yankoski said people can help the butterflies by planting native milkweeds and wildflowers. 

“Have a garden that is part of the ecosystem. If you are planting plants that aren’t being eaten, that you aren’t finding caterpillars on that are not attracting butterflies and pollinators, you’re not part of the ecosystem,” said Yankoski. 

Make sure to have flowers that bloom in the spring, summer, and fall when they head back to Mexico. 

“Along the way, they need to be drinking lots of flowers in the fall, so they can be fueling up for the 2000-plus mile journey all the way down to central Mexico,” he said. 

Yankoski said Monarch butterflies are facing difficulties on many fronts and we must look at the big picture. 

“We need to be restoring their habitat. We need to be reducing our use of pesticides and herbicides, working with the authorities in Mexico to protect their over-wintering grounds,” said Yankoski. “We always tell people if you’re planting flowers, you’re doing your part, that’s great. But it’s a much bigger picture than that.” 

U.S. Fish and Wildlife are monitoring the Monarchs closely, but as of last year declined to add them to the endangered species list. They said they acknowledged it was potentially warranted, but they were going to focus their resources on other species and they’ll revisit it in the future.