Scott Hall:
Hey, Jim, welcome.
Jim Paruk:
Hey, thank you. Great to be on.
Scott Hall:
Yeah. We're about 15 below here and, and mostly clear skies under a couple feet of snow. What's it like in Maine?
Jim Paruk:
So, we've got 20 degrees, clear skies and we just had about four inches of fresh snow powder. So, the trees are covered and it's quite lovely.
Scott Hall:
Sounds pretty, yeah.
John Latimer:
And the loons have all gone south for the winter?
Jim Paruk:
Well, yeah, you would think so, 'cuz loons are smart. Clearly, most freshwater lakes are iced up, so loons typically migrate. But the loons in Maine, unlike Minnesota, just migrate to the coast. So, they have a short journey, 60-200 miles, while your Minnesota loons to go pretty much to the Gulf of Mexico and to the Eastern Atlantic. So, they're traveling 1500-plus miles. And because of that, [here's] a cool little factoid! Loons are smaller in Minnesota than in Maine by almost by 20-25%.
John Latimer:
Wow.
Jim Paruk:
And the reason for that, we feel, is that if you're going to travel a long distance, it's better to be lighter. You're more efficient. You think about the Tour de France bicyclists: They tend to be lighter, the ones who climb mountains. So, the loons in Minnesota are a lot smaller than the ones in Maine. So, when I came to Maine, I was really surprised just how large loons are in Maine because they don't migrate as far.
Scott Hall:
Now, are you serious?
Jim Paruk:
I'm dead serious.
Scott Hall:
Okay. I... That makes sense to me. So, how long have you been in Maine?
Jim Paruk:
I've been in Maine since 2011 now, so probably for the last 11 years.
Scott Hall:
How'd you get interested in loons?
Jim Paruk:
A college buddy really started me. He was trying to figure out a way how to catch loons to put bands on them for his master's degree. This was in 1987/1988. And I was a good friend of his in 1980, 5-10 years earlier. And I said, "Sure, I'd love to try to help you." So, then I went to a place called Seney National Wildlife Refuge up in Michigan. And Dave Evers was trying to help figure out how to catch loons to put bands on them, so we can actually study them. Because you can imagine- you got two chickadees at a bird feeder or two blue jays. You don't know if [this one's] a male or [that one's] a female, how old they are. [You can't tell them apart.] And that was the same story with loons, because we couldn't identify them as individuals. We didn't know how long they lived. Was it a male, was it a female? And so, by figuring out how to put colored bands on loons, it really allowed us to identify individuals. So then we can track them over time, we can ask, "Do they come back to the same portion of the lake?" For example. "Did they come back year after year?" And that's really how I got started in loons. So, kind of serendipity.
John Latimer:
I'm curious, Jim. I actually worked with Kevin Kenow from the USGS implanting transmitters on juvenile loons. I got to go out and help catch loons with him one night, and it was pretty exciting. I'm curious, if you're banding these loons, where are you putting the bands? Because if they're on the legs, you don't see a loon's leg that often! <laugh>
Jim Paruk:
No, John, that's a great question. And it would be ideal, for example, with California Condors (a threatened bird, and we're trying to study them) they can potentially put a wing marker on, and then you could read it. And on geese, oftentimes you can put a neck collar. But none of those techniques really work with loons. As you identify, the leg band is mostly underwater, so it takes a lot of patience. But, about once an hour, the loon will start preening its body and rolling, and then that's the chance to see the band. But it takes a lot of work to do that.
John Latimer:
I was thinking about that. And I've seen the loons when sometimes they stretch that leg out behind them. I thought, boy, you'd sit for a while waiting for that to happen.
Jim Paruk:
Yeah. Dedication that biologists have.
John Latimer:
Yeah. So let's go on to talk a little bit about the interaction between the loons and the eagles, because that's essentially the focus [of your presentation with Itasca Waters]. And I have been curious about that, because I have both an eagles nest on the lake I live on and loons that nest there. So tell me more.
Jim Paruk:
Well, just to clarify, John, this is more of a discussion with eagles and loons. I haven't really studied them in depth. I've studied other aspects of their biology, but the eagle/loon interaction is relatively new for me as well. Did you have a specific question, or just wondering about eagles and loons?
John Latimer:
Well, what threat do eagles pose to the juvenile loons? I also have trumpeter swans that nest on the lake. And one day last summer, I found a baby trumpeter swan far removed from the lake, in a place where it could not have walked or flown. It was dead and had been carried there. I assumed [it was done] by an eagle, because I don't know what else could pick up a bird that was nearly the size of a mallard at that point. So, what is the relationship between eagles and loons? Are they predating the loon population?
Jim Paruk:
I'll try to give maybe real brief historical perspective as well. Eagles and loons have been around for over a million years. And during that time, clearly they've coexisted and eagles are generalists, right? They're not specialists, they're not preying on loon chicks or incubating adults. They're trying to make a living in the environment. At times, I wouldn't want to be a Bald Eagle. I think it's pretty tough existence for many predators. They're going to perch and wait and be patient, they'll feed a little, scavenge, they'll feed on birds, mammals, fish (of course), and occasional turtles. So, the life of an eagle is pretty tough.
And what we've seen since eagles were listed and DDT was banned in the 1970s, they're now federally delisted, as most listeners are aware. Eagles are doing really well in the state of Minnesota, and all across North America for that [matter]. And so, as you have more eagles, greater eagle densities, they're going to come in contact with loons. And similarly with the ban on DDT, loon numbers have been exploding since the 1970s. And loon numbers are extremely high in most states across the eastern seaboard. So, because eagles and loons both nest on lakes, there's going to just be more interactions and more opportunities for them to interact. And so, many people have seen eagles attack [loon] chicks, eagles attack adults. There's been more observations: there's more people I think, with COVID spending time on the water. And so, there's been many more observations of these predation attempts (and, at some levels, being successful). So, we're seeing more of this. And I guess the question that you're asking, and rightfully so, is, "are they having population level impact?" And a little bit of research that I was able to do is that it seems that it's relatively minor, and that there's other threats to loon populations that really need attention as well.
For example, lead toxicosis continues to be a fairly high mortality factor for loons, not only in Minnesota, in New England, as well in the other Midwest states. And also just boat [collision] trauma seems to be on the increase. Monofilament entanglement will injure or prevent a loon from feeding as well. So I think [in terms of the] eagles: we still have much to learn about this [interspecies interaction]. I think we continue need to keep monitoring these interactions as well. But precursory, I would say it seems to be having small effects, but ones that we should certainly keep an eye out for.
Scott Hall:
So you think it's premature to suggest conservation measures, because we just don't know enough?
Jim Paruk:
Yeah, I feel more comfortable with that. I think as a scientist, we tend to be fairly conservative and we want to see more data. And I think there's more data that needs to be gathered before we can make that statement. But, what I could say, is there's lots of lake associations. If they're using [loon nesting] platforms, there's measures you can take. There are avian guards that have been adopted by some lake agencies that are essentially a camouflage net placed over the loon nest, and that'll deter an eagle from predating on an incubating bird, for example. But it's pretty hard to come up with conservation measures to prevent eagle predation on loon chicks. Loon chicks, we should clarify, are most vulnerable when they're four weeks or younger: When their motor skills are not as developed. And if loon chicks can get beyond that, they seem to be able to survive and make it because they can dive deeper and they're more alert in case there's an eagle predation.
John Latimer:
Jim, that's that's comforting news. And one that I suspect I've always felt internally: that they've been doing the dance together for a long time and they've both been successful. So, I want to close with some comments about a bird that we're familiar with here in Northern Minnesota called the Northern Shrike, and one of my favorite birds. And I understand that you have done a little research on the Shrike as well. Can you talk a little bit about that?
Jim Paruk:
Sure. Northern Shrikes, I would agree: What a fascinating bird. It's a songbird that's turned predatorial. It hunts other songbirds, sometimes birds larger than it itself. Sometimes, they'll impale birds or mammals on thorns, and they can get their name "Butcher Birds" for that reason. It's a prey item that they can return to. So, they have larders that they go out into the field and recover.
It was also very difficult to catch Northern Shrikes. And a woman out in Colorado figured out a way how to do that. And I was working with a DNR biologist in Wisconsin, Ryan Brady, and figuring out how we can adopt [her technique] to catch Northern Shrikes. And so, when I was living in Northern Wisconsin teaching at Northern College, we went out and figured out how to catch Northern Shrikes and band over 90 [of them]. And we were able to get very useful information on territorial size: "Did they act territorial?" "What did they eat?" And there was a fun little six, seven year run looking at wintering Northern Shrikes in northern Wisconsin.
John Latimer:
Do they maintain a summer residence here, or are they migratory north?
Jim Paruk:
Yeah, they're migratory north, so they're up in Canada, mostly boreal forest. They're mostly nesting up in Canada as well, so we don't have any nests on the Northern Shrike.
John Latimer:
So the territory you're talking about is maintained over the winter, and something that they just keep for purposes of gathering food?
Jim Paruk:
Correct. Yeah. And the shrikes seem to return to the same place winter after winter.
John Latimer:
Oh.
Jim Paruk:
And then they'll compete with other shrikes as well to maintain their territory. In the wintertime, they like hedgerows, fields, farmlands, recent burned areas: more open [habitats] with some brushy hedgerows on the side. And Minnesota has a fair amount of that habitat. To give you an example, John, when I came out to Maine... Maine's the most forested state in the lower 48, and there's just fewer openings and gaps, and consequently, there's fewer Northern Shrikes. So, it's been difficult for me to continue my research on shrikes out here in Maine for that reason.
John Latimer:
Well, it's interesting to hear you say that. I was a rural mail carrier for 35 years, and there was a spot on my mail route where every winter I could count on seeing shrikes. And you have described it to a T! <laugh> Old fields and hedgerows. They had a favorite perch on top of a single tree out in the middle of the field. And yeah, they are fascinating birds.
Scott Hall:
Hey, Jim, John and I were talking before we went on with you. How deep can a loon dive?
Jim Paruk:
Over 200 feet, probably 240.
Scott Hall:
Wow.
Jim Paruk:
And I wouldn't be surprised if it's closer to 300 feet, like maximal depth, but we don't have quantitative data for that. But so far, we do know that 240 feet seems to be a very comfortable range for loon to dive to.
Scott Hall:
You mentioned how tough a life eagles have are, do loons have an easier life?
Jim Paruk:
Well, I think they're going after fish. And I think they're so remarkably adapted structurally, anatomically, and physiologically, they're so hydrodynamically designed like a torpedo that they seem to be very successful and efficient predators. So if I had my choice, I would rather be a loon.
Scott Hall:
<laugh>. Okay.
John Latimer:
<laugh>.
Scott Hall:
All right. And you're going to cover a lot of this info about loons in the virtual learning session this Thursday [2/2/23]. But here's a question from a listener: Do loon calls vary a lot? In other words, do they have individualized calls? Because it's such a iconic sound for us here, on our lakes with the open water.
Jim Paruk:
Yeah. So the wail and tremolo calls (which are the ones that were most familiar and associated with loons,) those are not as much individualistic as just very general. And so I think it's difficult to separate loons out by an individual wail or tremolo call. However, the yodel call, the longer call that the males make, that is individualized. And researchers can separate one loon from another just based on its yodel.
Scott Hall:
All right.
Jim Paruk:
That helps you out, hopefully!
Scott Hall:
Yeah, a little bit. Now, your book mentions "uncommon encounters" in the title. Can you tell us one or two uncommon encounters you've had with loons?
Jim Paruk:
Well, yeah, sure. One of 'em is out in the Northern Gulf of Mexico. [We were] probably six miles out in the ocean in the middle of the night, trying to catch loons. And just imagine that, right? There's 'uncommon encounters'! And so, I'm out on this long fishing boat, really small, and there's this large buoy that's being pushed around by the current. The boat captain says, "Hey, sometimes they hunt alligator gar. They'll leave a baited hook out there. I bet you we might find an alligator gar," because this big buoy was moving against the current. So, I leaned off the bow of the boat, raised my hands down into it, and lo and behold, out comes a big sand shark. And now I'm a loon biologist, right? There's a sand shark, literally 12 inches from my face. There were some moments of panic in that case. So, that's one of those uncommon encounters that we've had with the loons.
Scott Hall:
All right. Well, folks can hear a lot more about your book, Uncommon Encounters, as well as ask you questions about what you've learned about loons in Maine and across North America this Thursday. And thanks for giving us a little preview of your program this morning.
Jim Paruk:
Yeah, sure. Thanks Scott and John. Glad to be here.
John Latimer:
Yeah. Thank you, Jim. Just as a quick conclusion here, I'm an open water swimmer, and I find that loons are incredibly curious. If I go out swimming early in the morning, they'll come right up to me. I've been within four or five feet of loons just swimming along beside me to see what's going on. They're really amazing birds.
Jim Paruk:
Oh yeah. Wow.
John Latimer:
And I had one time that swam next to me underwater, and I got a chance to look at how streamlined they are when they're swimming underwater. And I had my dog with me, a Labrador retriever, and she started swimming at the loon, and the loon was absolutely unconcerned. It was like, "this is nothing."
Jim Paruk:
Yeah. Amazing birds. That's great.
John Latimer:
Jim, thanks for joining us this morning. I look forward to hearing more on Thursday. It's going to be a great program. Thanks for coming along.
Jim Paruk:
Okay. Sure thing. Thanks, John. Thanks, Scott.
Scott Hall:
You bet. Jim Paruk joining us from Maine this morning. And he'll be talking about his book "Loon Lessons: Uncommon Encounters with the Great Northern Diver" and some of his research and thoughts about loons and their relationship to eagles. This Thursday [2/2/23] at noon, it's presented by a Itasca Waters and their Water Wisdom Virtual Learning series. It's at noon. And you can register for free this Thursday at ItascaWaters.org.
