'A birdhouse for loons': DNR studying human-made platforms loons can nest in

[LOON CALLING] NINA MOINI: Well, this time of year, Minnesota's beloved loon is settling back onto one of the state's many lakes after wintering between the Gulf of Mexico and along the Southern Atlantic Coast. They're looking for a good place to nest and raise their young over the next few months.

Volunteers with the DNR have spotted fewer and fewer chicks growing up on Minnesota lakes in recent years. It's led the agency to study ways to make raising a loon family on one of Minnesota's lakes more desirable. One option they're looking at are human-made floating homes that loons can nest in. Here to tell us more about that and what else our state bird is up to this time of year is Tim Mitchell. He's the DNR's Loon Program Coordinator. Thanks so much for your time, Tim.

TIM MITCHELL: Thank you for having me on today.

NINA MOINI: Well, you know that we love loons in Minnesota. It's a treasured part of our state. And I think people feel that it's really something they feel ownership. They want to help out. So I'm really glad to have you on the program today so that we can learn more about what's going on. So these floating human-made nests that you're studying, what do those look like, and why are they hopeful for loons?

TIM MITCHELL: Yeah, so what we call them are artificial nesting platforms. And there's a few different designs that make them. But what we're putting out is a PVC structure that floats filled with foam. And we put mud and vegetation on top of it and anchor it offshore. So it's a floating platform nearby where loons might have a history of nesting, and it allows them to nest off the shoreline, which can help with predators like raccoons that might get their eggs, things like that. So it's a birdhouse for loons. It doesn't force them to nest there, but sometimes, they choose to hop up on and create their nest there.

NINA MOINI: And I mean, is it important that it looks familiar to the loons? I mean you mentioned putting some mud on there and trying to make it a desirable spot. How do you make sure that it'll be familiar enough for the loons?

TIM MITCHELL: Well, yeah, that's a good question. So what we do is we put mud from the shoreline right there. So we bring it out and prep it in the site. And then we will cut vegetation from the shorelines and put it right up on the platform. So it grows up naturally. And it takes the loons sometimes a couple of years to warm up to this thing that's unfamiliar with them, so they don't necessarily take to it right away. In our study, we only had about 2% of them used the first year. And then it's gone up each year. So we're up to around 33% in our third year. And we're putting them out for one more year in our study.

NINA MOINI: OK, cool. So tell me about the need for this. It doesn't sound-- a lot of times we'll hear about a population when it's going extinct or things are scary or it's an emergency situation. That's not the case. You're just looking at patterns and trying to be helpful in more of a preventative way. Or what are you seeing within the loon population?

TIM MITCHELL: Well, we're funded from the Deepwater Horizon oil spill settlement. So a bunch of loons were injured in that oil spill. And so this is part of the restoration project that funds this to help the loons recover. So that's where our funding comes from. We work with the US Geological Survey. And so when we were thinking about we're the only inland state that got money from that settlement, and when we were thinking about ways to help loons, there's a few things, but this is a known conservation practice that can help. And so we've been deploying them in lakes that had low loon productivity and hoping that it can help boost that hatching success. Getting more chicks in the lakes.

NINA MOINI: And what about why the lakes have become, I guess, less desirable?

TIM MITCHELL: Yeah, that's a challenging question. We've seen some recent declines in recruitment, but we don't necessarily have a cause. We know there are some direct sources of mortality for loons from people like boat strikes or tangled fishing line, lead sinkers-- things like that. But then there's a lot of indirect effects, like losing shoreline habitat and potentially reduced water quality. So we don't necessarily have a smoking gun for these recent trends, but it could be a little bit of all of the above.

NINA MOINI: That's great. Thank you. That's great perspective. Would you tell us about the regions in the state, within the state that have been seeing fewer baby loons? And you know why that may be?

TIM MITCHELL: Again, we don't necessarily know why we have a Minnesota loon monitoring program, which has six index areas across the north central part of the state. And we've been recently seeing some declines in some of our northern loon populations. And so there seems to be a stable adult population, but we're just seeing fewer juveniles recently in the last couple of years. And so we are trying to look into that more. And it could be any of the topics that I just mentioned, but we're not exactly sure why. And we're going to continue monitoring it. These natural fluctuations can happen as well. So they could be doing just fine. And this is just a natural dip for one reason or another.

NINA MOINI: What about the overall loon population in the state? Is it healthy?

TIM MITCHELL: Yeah, we have the most loons of any of the lower 48. We suspect we have about 12,000 adult individuals that come back here and breed in Minnesota every year. Obviously, lakes are their habitat, and we are the land of 10,000 lakes. So we think we have a pretty robust and healthy loon population. And so we just want to keep it that way.

NINA MOINI: Absolutely. How can our listeners-- I mentioned that Minnesotans love loons. Is there a way that listeners can get involved-- maybe they live near lakes or could be part of monitoring populations? How could people help?

TIM MITCHELL: Yeah, we have a program called the Loon Watchers, which is great for individuals who are consistently on lakes during the summer. And so you can go to our website and figure out how to sign up for Loon Watchers. And that's a program where citizens can go out, and they take some basic animal surveys-- so basic reproductive surveys. They're counting loons, looking to see if they're on nests, if they're producing chicks-- those sorts of things.

NINA MOINI: Cool.

TIM MITCHELL: And a lot of those members then are also a part of their local lake associations and can be voices for conservation right there in their local community.

NINA MOINI: Great. I'm also curious, Tim, just about the life cycle of loons. So they're back in Minnesota now, looking to nest. What's next for them? What happens over the summer?

TIM MITCHELL: Yeah, so probably right about now, they are jockeying for their territory. So they're very territorial. And so they're claiming their territories and looking for nests. In the next week or so, they'll be hopping up on nests. They incubate eggs for about 28 or 30 days, and then you'll start seeing chicks show up. So usually late June and into early July, we see a lot of little fluffy chicks that hatch out, and then it's a full-time job for those parents feeding those chicks, making them grow quickly enough so that they can make a migration back south before our lakes freeze over in the fall.

NINA MOINI: Cool. And just lastly, Tim, how and where can folks see loons this summer, but from respectful distance in a way that will be helpful?

TIM MITCHELL: They are pretty well distributed across our lakes in central and northern Minnesota. So they eat fish. So you got to find lakes that are large enough to support fish. But more often than not, you can get out there on the water, and you've got a good chance of seeing loons.

NINA MOINI: All right, Tim, thank you so much. I learned a lot. Really appreciate your time.

TIM MITCHELL: Yeah, thanks a lot.

NINA MOINI: That was Tim Mitchell, the DNR Loon Program Coordinator.