Karen Oberhauser on the future of endangered monarch butterflies

CATHY: Minnesota's official state butterfly-- yes, we have one, the beloved monarch-- is now on the Endangered Species list. The International Union for the Conservation of Nature says the monarch butterfly was moved, for the first time, to its Red List of threatened species and categorized it as endangered, two steps from being extinct.

Joining us right now to talk about the future of monarch butterflies is UW Madison Arboretum director, Dr. Karen Oberhauser. Dr. Oberhauser was also at the University of Minnesota, where she was professor and a conservation biologist. Welcome back to the program, Doctor. How are you?

KAREN OBERHAUSER: Thanks, Cathy. It's great to be back here. I'm fine. Thanks.

CATHY: Good. I'm glad you're here. Say, I was a little surprised to hear this news last week because of all the efforts underway to help the monarch. What's happening?

KAREN OBERHAUSER: Well, you're right that a lot of people are doing a lot of things to help monarch butterflies. But the problem is that there are a lot of negative things going on at the same time.

So basically what's happening with monarchs right now is we're holding our own, thanks to the efforts of a lot of people. But holding our own isn't enough. We're not at a number that's going to be sustainable in the long-term for monarchs.

CATHY: What are the main dangers for the monarch butterfly?

KAREN OBERHAUSER: Well, there are two big things that are affecting them, and first is habitat loss. So monarchs need habitat throughout their annual cycle of breeding up here in the summertime and then migrating south to sites in Mexico and then overwintering in Mexico and coming back. So they need habitat available to them over this large, large space.

And the other thing that's a problem for them is weather. Weather conditions during any phase of that annual cycle can be positive or negative. So, for example, in one big storm in Mexico, 60% to 80% of the monarchs can be wiped out. And hot and dry summers are bad for them. And unfortunately, climate change models predict a higher frequency of conditions that aren't so good for monarchs.

So those are the two big things. There are other things that can kill them as well. So, for example, pesticide use is a problem. When people spray insecticides, those insecticides can not only kill the harmful insects, but they can kill other beneficial insects as well.

Monarchs can be in collisions with vehicles when they're flying next to across roads. They can be killed by a lot of predators and parasites. So there are a lot of things out there that can hurt monarchs.

CATHY: Wow. In 2020, as you know, US wildlife officials found that monarchs were threatened with extinction. But they decided not to add them to the Endangered Species list because they said conservation of other species took priority. Well, do you think in hindsight, that was just not the right move?

KAREN OBERHAUSER: Well, no. I agree with that decision. Certainly, what they said is that they weren't listing, and that's correct, that their numbers are declining to the point that the population has a good chance of being wiped out. But like you said, there are a lot of other species that are even worse off.

So well, the Endangered Species Act in the United States would have provided legal protection for monarchs, and this designation doesn't really have any legal protection from the International Union for the Conservation of Nature. This does really clarify the fact to people that monarchs are in trouble and that we need to do what we can to help them.

And I think the other thing that's really important to understand is that when we do things to help monarch butterflies, a lot of other species come along for the ride. So it's not just monarchs that are in trouble right now. It's all of the other species that they share habitat with, or not all, but lots of them. So we really need to do what we can for monarchs to help other species as well.

CATHY: I was going to ask to that end, what happens if the monarch were to become extinct? I mean, maybe some people would shrug and say it's just a butterfly. But what happens if that were to occur?

KAREN OBERHAUSER: Yeah, so that's a really interesting question. Of course, we don't know because it's never happened before. But one thing that we know would happen is that we would lose a species that people really care a lot about.

And this species makes connections between people and the natural world that very few other species do. So when we, as humans, start to lose those things that connect us to the natural world, I think we've lost something really important. And if we do lose monarchs, it really means that we're doing a pretty bad job at protecting the natural world. So I think it would be a symbol that things are really not right in the world if we lose monarchs.

CATHY: What realistically can be done to help the butterfly get off the Endangered Species list? I mean, we've got people who are planting pollinator gardens and letting their lawns go more natural. And that's wonderful, but what else needs to be done?

KAREN OBERHAUSER: Sure. Well, those things are really important. And doing habitat restoration on both small and large scales can really help monarchs. And especially in the face of climate change, if we have lots and lots of habitat that's spread over large areas, it's more likely in any given summer that monarchs will find the conditions that are good for them.

So, for example, last summer, we saw that we had really hot and dry conditions in the West, and things were just burning up literally. The East was pretty cool. And in the Midwest, things were pretty normal. So if we have habitat over large, large swaths of land somewhere, monarchs will be doing OK. So habitat is key.

The other things that people can do are help us study them. There are lots and lots of monarch-monitoring programs that people can join. In fact, we have an International Monarch Monitoring Blitz that's coming up starting on July, 29th. So this is something people can look up online and find out how they can monitor monarchs, whether they're in Canada or the United States or Mexico.

People can support organizations that are working to create habitat. So if people don't have their own lawns or gardens or areas that they can turn into habitat, they can support either monetarily or with volunteer help their local Nature Center or statewide organizations or national organizations.

And finally, people can spread the word. If you're listening to this and you care about monarchs, you can talk to your family and your friends and your neighbors and tell them to do their part as well.

CATHY: You have some good steps there. And I'm wondering, even if those steps are taken, is there any way when you have a species on this list, is there a timeline to when scientists think extinction is possible? How close are we, I guess, in terms of years, perhaps, if that's even possible to look into your crystal ball?

KAREN OBERHAUSER: Yeah. Well, for good or for bad, I don't have a crystal ball here. And sometimes having a crystal ball might get depressing. But I think that really there's a lot of chance events involved.

What the problem is with monarchs is if the numbers are very low and we have a catastrophic event, say, in the overwintering sites in Mexico that kills off a lot of the monarchs, if we go from low to even lower, there's a chance that the monarchs wouldn't be able to recover. So what we want is to get the population back up to the point where there won't be such a big risk of that happening. So right now, holding our own isn't quite enough. We need to do better.

And of course, the goal of putting a species onto the Endangered Species list is that we do things to help it, and we're able to pull it off of that list. And we've seen that happen with the Endangered Species Act in the United States, where species have been removed from the list. Unfortunately, sometimes they go extinct, but in some cases, they stop being endangered. So that's always the goal with this kind of recognition, but I can't give you a timeline for either the good news or the bad news.

CATHY: All right. But I appreciate all the information, though. Thank you. It was great talking to you again.

KAREN OBERHAUSER: Thanks a lot. It was good to talk with you as well, Cathy.

CATHY: Dr. Karen Oberhauser has been with us. She's the director of the UW Madison Arboretum. Prior to that, she was at the University of Minnesota, where she was a professor and conservation biologist.