capture

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A three-hour tornado watch haunted us as we prepared to scout Middle Cullen Lake for capture at 9:10 p.m on July 24th. There was little wind, and conditions seemed oddly tranquil. But the crew — Richard, our 70-year-old captain, two young techs, Korben and Taylor, and myself – had agreed beforehand to watch the skies closely, check radar, and return immediately to the boat landing at the first sign of foul weather.

Distant lightning 50 minutes later put us on edge. By that time, though, we had confirmed that the Middle Cullen-Rushes pair still had their chick in tow but that two other Middle Cullen pairs, East and Central, were newly chickless.* These losses were a blow; in both cases, the chicks had reached at least four weeks of age and seemed out of the woods.

After pausing a few minutes to confirm that the lightning did not indicate harsh weather near at hand, we proceeded westwards. I was determined to use what little light remained to look for the two 8-week-old chicks cared for by a fourth pair on the lake, Middle Cullen-West. At length we found the West pair just east of the south-facing point by the huge resort. Yet no young were evident nearby. I groaned as Richard coasted us to a stop thirty yards from the relaxed duo. “These two have been snakebit”, I said, making no effort to hide my frustration. “They had chicks in 2022, and nothing since. But they are a sweet pair, and frankly, I refuse to accept that their two big youngsters could simply vanish. It is just too horrendous that three out of four pairs with chicks on Middle Cullen could lose them”. My comment contained a desperate plea to which no one knew how to respond. The team fell silent.

Several minutes passed, and still the West male and female sat contentedly near our boat, ignored us, and gave no sign that they had young in the vicinity. Taylor glanced over at me expectantly, waiting for me to render my official decision that the chicks were gone. “Let’s wait a few more minutes”, I said weakly, more out of denial than anything else.

A pall descended over the boat. What I wished to regard as expectant watchfulness began to feel more like a vigil. Hoping perhaps that I could will the chicks back into existence with intense effort, I stood in the bow and scanned the lake in all directions with my binoculars. Three 360-degree sweeps, though, revealed nothing more than the calm breeding pair just west of us. “I don’t see any chicks”, Korben announced, his tone intending to convey that he was looking hard and hoping for the best but that we were reaching the point at which no reasonable observer could conclude that the chicks were still alive.

Moments before I yielded to the inevitable and pronounced the West chicks gone, I spotted two dark forms in the water 150 yards east of us. They were close enough to an extensive patch of bulrushes that I was tempted to dismiss them as mallards, but the failing light and distance made it impossible to be sure. Korben followed my gaze with his binoculars. “Those might be loons…..I think they are adults!”, he said excitedly. As we watched the dim, ill-defined shapes, we realized that they were swimming slowly in our direction, and gradually their outlines were becoming more distinct. “Those are chicks!” I half shouted a minute later. Richard started the motor and removed us from our position between the approaching young and their parents. We paused for a moment to look back and enjoy the slow-motion family reunion then proceeded eastwards wearing broad grins. The dramatic, last-minute appearance of the West chicks meant that we could return later that night — if time permitted – to catch and mark them.

Five hours later, we faced a quandary. “There’s no way we’re making it through this channel,” Korben proclaimed, his tone conveying a sense of authority. Though just 22 years old, Korben is the driver of our 16-foot motorboat and the only one of us licensed to operate it in Minnesota. He is experienced and knowledgeable in piloting watercraft, easing them through weedy and shallow stretches, and extricating them from sandbars where they become stuck. Taylor, 21, another tech and our expert spotlighter, agreed with Korben. “Yeah”, she said, “it only gets shallower up ahead”. She illuminated the sandy spot off of our bow to emphasize her point.

We had already had an eventful night. Following our weather scare, the receiver for our trailer hitch had been stolen right out of the back of Richard’s truck at around midnight. Our return to the boat landing on account of worrisome lightning had spooked the thief, whose truck raced off with tires squealing just as we set foot on the dock. But that misadventure had cost us an hour and a call to Terri, who drove half an hour to reach us and bring a new receiver.

Curiously, our hair-raising night was also our most efficient evening of banding all year. After shifting to Lower Cullen boat landing – much more public than that at Middle Cullen – and leaving Richard in the truck to ward off the thief if he returned, the two techs and I had quite magically found, caught, and marked the only three territorial pair members on the Cullens that had remained unbanded — in three separate pairs. And we had bagged three big chicks to boot. We were on a huge roll.

At a few minutes past three, we sat at the northeastern corner of Lower Cullen, having just caught and banded the Lower Cullen-Northeast female. We were separated from the Middle Cullen-West chicks we had seen at dusk only by a three-minute boat ride and a trip through the short channel that connects Middle and Lower Cullen lakes. With only one hour of darkness left, moreover, passage through the shallow channel offered us our only opportunity to capture the West chicks before daylight.

I responded to Korben’s pessimism about the channel with a call to my techs’ adventurous spirit. “Let’s give it a shot!” I said cheerfully. Recalling the thrilling sight of the West chicks at dusk, I added, “We have a date with those two big chicks!”.

Korben humored me. He raised the motor as high as he could and eased slowly towards the narrow opening. We ground to a halt 15 yards short of the channel. “It’s six inches deep!” Taylor objected. “There is no way, Walter.” But her pessimism and Korben’s only strengthened my resolve. “Let’s hop out to lighten the load,” I suggested. I shed my shoes and slid in stocking feet into the warm, shin-deep water. The techs exchanged a look of disbelief but grudgingly followed suit.

With the entire loon capture team now in the lake, the boat floated much higher. The bow found the sandy bottom again as we entered the channel, but we discovered that the three of us could nudge it forward little by little to reach and then pass through the opening. Three minutes later the motorboat was afloat again, and we clambered back aboard. The motor pushed us out of the channel and into Middle Cullen Lake. For a moment, I imagined that we had achieved a feat that comparable to that of Humphrey Bogart in “The African Queen”. But the comparison fails under close scrutiny; our lake water was clear, our passage short, and we took on no leeches.

I savored the victory quietly. I was delighted to think that — after all the adversity we had faced — we were now in a position to cap off our huge night of capture by placing colored bracelets on the monstrous Middle Cullen-West chicks. But my first task was to restore goodwill. “You guys were amazing!” I said, touting the lake crossing as a team victory rather than the near mutiny that it had in fact been. “I really appreciate you hanging in there!”. Korben and Taylor’s grouchiness gave way to elation soon after, although it was thanks to the loons, not me. The two West chicks we had discovered five hours earlier were not difficult to capture, and we all gawked at their size, adult-like plumage, and docility. “There you go!” Taylor said to the larger one as she placed it gently over the side of the boat after banding and watched its colorful legs pump alternately as it swam away. “Have a good life…..and come back to see us!”

* — The featured photo shows the capture team scouting territories for loons shortly before nightfall. Photo by Sharon Gibbons.

Below you can watch a video of Taylor releasing a chick almost as large as the one she let go on Middle Cullen-West. This one, though, was from Kimble-East.

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There are several moments each year when I find myself out on a lake at night during capture season and suddenly think I must be insane. One such moment occurred at about 2 a.m. last night in Minnesota. Richard was driving the motorboat; Owen and I were perched in the bow scanning for loons. We swept the spotlight back and forth, back and forth across the dark surface of East Fox Lake. But we spent very little time in contact with loons. Our spotlight mostly caught dense, swirling tendrils of fog hanging in the air. Occasionally we broke free from this suffocating cloud for short intervals and the spotlight suddenly gave us an unobstructed view of 100 yards in every direction. Fortune was not on our side, however. We saw no loons in parts of the lake that were free of fog.

Loon capture — even loon-spotting — seemed highly improbable under these circumstances. I looked back at Richard behind me and Owen to my left. Their presence somehow reassured me that what we were doing — trying to locate a family of diving birds in total darkness and pea soup fog on a 241-acre lake so that we could lure them close to the boat with imitated calls and scoop them up in a muskie net — qualified as rational behavior. We searched on, fruitlessly. “Kill the motor Richard”, I said finally. “Let’s try playbacks.” Yet the loon pair at East Fox-South and their two 7-week-old chicks did not give away their position by vocalizing in response to our crisp recordings of wails from Maine and yodels from Michigan. Maybe it was regional bias.

We continued stalking the silent loon family. I directed Richard to steer right or left, so as to remain within the loon pair’s favorite part of the territory. Fifteen, twenty minutes passed. As our hopes of finding the family were beginning to fade, we caught sight of two black loon heads ten yards apart, partially obscured by a fog bank. “We need the unbanded male”, I reminded Owen. “Okay”, he whispered good-naturedly. With the two adults separated, we could not determine which was larger, forcing a split-second decision. Owen spotlighted the nearer adult. As we drew close to the bird, however, we realized our mistake. “Banded!” we both shout-whispered simultaneously. Owen swiveled the light quickly to the male we wanted. We crept up to him, while I imitated the scratchy whistled call of chicks in an effort to freeze him on the surface. At first, we were hopeful. The male did not shrink from the spotlight, as many loons do, and he was interested in the chick call. Alas, though, he was an unpredictable diver. He remained near the surface where Owen could track him with the spotlight, yet he swam first at — then underneath — the bow of the boat. I could not get the net in the water to catch him. After a minute or so, he vanished into the mist.

Moments later, the female wailed to our left. “Let’s go for her”, I told him, and soon after I had scooped her into the boat and — with Richard’s help — Owen had tucked her neatly into a padded, ventilated box. “Maybe the male will find the chicks”, I said hopefully. It was a reasonable expectation. We had seen the sole parent seek out the chicks many times before, once we had removed its mate from the water. And an adult swimming with its chicks is usually highly protective of them and less apt to dive. But we did not blunder into the male and chicks after that first encounter, despite 20 more minutes of puttering around in a cloud.

We gave up, motored to shore with the female, took a feather sample and blood drop, weighed her, and released her off shore. It had been a frustrating middle of the night boat ride on East Fox. We had failed to catch the bird we had targeted on the South territory. Yet we had banded four new chicks earlier in the evening — including two on socked-in East Fox Lake — and recaptured three adults. That brought our two-state tally to 40 unmarked adults newly banded, 88 chicks banded, and 27 adults recaptured. Looking back, we had quite a lot to show for our labors this July, considering that we face variable weather conditions, unpredictable study animals — and engage in an enterprise that seems to verge, at times, on outright insanity.

Pictured are Cora from the Minnesota team and Korben from the Wisconsin team.

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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.