Why is Chicago such a critical spot for monarchs?

We’re right in the path of the Central Flyway [their annual migration trail between Mexico and Canada], and because of the species’ life cycle, the monarchs that are born here are the ones that actually make it down to Mexico to spend the winter there.

Monarchs have been in steep decline the last couple of decades. Why is that?

Habitat loss. Milkweed is their main food source, and it used to grow everywhere. But people started using pesticides and herbicides that killed all of the nectar sources. The population has fallen from an all-time high of nearly one billion in 1996 to a low of 34 million in 2013.

There was optimism last year that things were improving, though, right?

We had the warmest fall on record [in some parts of the country], and that affected migration—you had monarchs leaving later, in November and December. People were thinking this is great to have extended growing seasons. But if you can’t get to your overwintering spot before winter weather hits, you’re toast.

What is the Field Museum doing?

We need an additional 1.8 billion stems of milkweed to help prevent further population loss, and we were tapped by the U.S. Fish and Wildlife Service to lead this project. That’s a lot of milkweed. The question is: Where are you going to put it? Cities have a much bigger role than previously recognized. We piloted the work in four major metropolitan areas: the Twin Cities, Chicago, Kansas City, and Austin. We’ve started looking at high-resolution mapping data to find any plantable space—anywhere you might put, say, grass, you could put pollinator-friendly plants instead. The biggest opportunity is in people’s front and back yards.

I live in a high-rise. Anything I can do?

One of the biggest questions we get is, “I don’t have a backyard. Can I do these milkweed plantings? Will I get monarchs?” And the answer is yes. You can have containers on balconies. Monarchs do not seem to be impeded by heights. People have seen them as high as 12 floors up.

See fieldmuseum.org/monarchs for more information on creating a monarch garden, making a container planting, and more.