Perched on the bow of a small motorboat in the middle of the night, I sweep a spotlight back and forth across the lake’s surface. My goal is simple. Find any small item resting on the dark water that catches the light. “Buoy”, Claudia proclaims in my ear as I freeze the spotlight on one such object that, at first blush, appears to be a loon. “No”, she barks a moment later, when I find a floating clump of vegetation. But shortly afterwards, the light falls upon something small, fuzzy, and brownish that becomes more and more loonlike as we approach it. I hand the spotlight backwards over my head to her, scooch as far forward as possible on my knees, and glance at the net to confirm it is untangled. Richard slows the boat and turns towards the loon family. “Adult!”, I whisper to Claudia — needlessly, because we had already agreed that we would first attempt to catch the parents. She trains the light on the larger of two adults whose physical features become dimly visible as we pull within fifty meters. On this occasion, luck is on our side; the male and female become alert as we draw near, but neither dives. We net the male without difficulty and, shortly afterwards, the female. The chick dives once after we fix him in the light. Seconds later, attracted by my loon calls, he wheels, swims towards the boat, and dives smoothly into the net that I place in his path. We quickly text Terri so that she can prepare the bands and datasheets on shore. Twenty two minutes later we have marked and weighed all three loons, transported them back to the capture site, and released them. Then it is on to the next lake.
One’s world narrows during loon capture. In the moment, all that matters is whether we netted this or that adult or chick we wished to band. Now that the sleep deprivation and tunnel vision of the capture period has subsided — and our nips and scrapes from loon bills have mostly healed — we can look back at our achievements over the season as a whole.
Between West Fox Lake in Minnesota, where our efforts began, and Oneida Lake in Wisconsin, where we wrapped up our season, we captured and banded 134 loons this year. Terri and Richard saved us in Minnesota with their expert boat-handling and organizational skills. Emily and Danny from the Wisconsin team were essential to our capture there. A huge thank you to all team members, who made 2023 a great year.
The research landscape differs starkly between the two study areas. In Minnesota, breeding pairs on Kego, Mitchell-East, Mitchell-West, Goodrich-Southeast, O’Brien, Clamshell, Kimble-West, Margaret, Big Trout-Far West — and dozens of other territories — got bands for the first time. The return or non-return of these adults in future years will allow us to refine our estimate of adult survival in the region and build the first-ever quantitative population model for the state. Thanks to our growing list of Minnesota partners and friends, who greased the skids for our work there with donations of funds, lodging, field work, lake access, advice, information about loons on their lakes — and moral support!
Having marked almost all adults in the Wisconsin Study Area decades ago, we now focus on marking chicks. Chick mass, we now know, provides a convenient assay of water clarity during the chick-rearing period. While we have already shown that increased black fly populations and falling water clarity have dealt the Wisconsin loon population a devastating one-two punch, there is more work to be done in the state. If we can pinpoint the exact environmental factor that reduces water clarity — our current research target — we might learn how to stem the population decline.
All of our research findings require loon capture. Although it is not foremost in my mind at those moments when I am kneeling in the bow of a small motorboat and inspecting fuzzy brown spots on the water, our work — our ability to learn about loon populations and what ails them — depends critically upon catching loons, weighing loons, and knowing who they are.
Thanks to Barbara Krimmer of South Two Lake in Wisconsin, who took this nice photo of the female (left), male (right) and two big chicks there.