chicks

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I have started to call it “the Great Void”. It is the period between a chick’s first autumn and the point — at 2 to 4 years of age — when it has matured, molted into adult plumage, and returned to the breeding ground to look for a territory. Why “void”? Because we know almost nothing about loons during this period.

The Great Void used to be a nuisance. It was frustrating to think that our birds were passing through so many critical life stages without us knowing where they were or whether they were alive. But we have now pinpointed high mortality of young adult loons as the greatest threat to the loon population of Wisconsin and, more recently, Minnesota as well. “Nuisance” no longer captures the depth of our frustration. We now have to admit that we know least about our loons during the time when it matters most. So I think we need to begin to describe the Great Void as a grave concern.

Yet we are not completely in the dark. We get a glimpse into the Great Void now and then. Here is the story of one glimpse we got in March of 2024 from the wintering grounds.

As soon as he spotted it, Jim “Crater” Anderson could see the bird was in trouble. Seabirds in Panama City, Florida do not lounge on the beach in late afternoon sun like tourists from Ohio. And this one was looking especially out of sorts. It was well above the high tide point, sitting in dry sand. Crater did not think twice about interrupting his daily 10,000 steps to come to its aid.

“That is not how a duck should sit”, Crater thought, looking at the bird. Indeed, with legs splayed right and left of its body and belly in the sand, it was a curious sight. The animal skootched awkwardly across the beach and flapped frantically as he approached to within five yards, making him wonder if its legs were broken. At that moment, he felt strongly that he must capture the bird and take it to someone who could help. He removed his grey hoodie and, crouching low to the ground to appear less threatening, crept still closer. “It’s okay, I am going to get you to someone who can fix you up”, he murmurred reassuringly.

The bird was not mollified by Crater’s soothing words. Now that he was within six feet, it whipped its head around and eyed him suspiciously. He steeled himself and grabbed it, enduring its painful nipping at his arms and hands. As quickly as he could, he swaddled the bird in his hoodie to calm it and walked briskly to Rick and Sheila Harper’s house. “They have parrots”, he reasoned. “They’ll know what to do.”

The bird he was carrying was bigger and heavier than he had thought it would be – much larger than any duck he had handled. Its bill was thick and dagger-like. Its legs were not broken, just connected at the very end of its body. And – this was the biggest surprise of all — someone had placed four brightly‑colored bands on the bird’s legs. “What is that all about?” he thought.

When he arrived at Rick and Sheila’s, Kim Youngbeck was also there. The four friends placed the bird in a cat carrier that was snug but secure and set about trying to learn what kind of bird it was and how they could help it. Sheila’s parents are birdwatchers who live in Park Falls, Minnesota. She sent them some photos in hopes that they could help with the ID. “That’s a loon!”, they announced with equal parts excitement and concern.

The Florida Fish and Game contact they spoke to informed them that a loon would not do well in captivity and that they should return the bird quickly to where they had found it. Dutifully, the friends walked back to the beach. Night had fallen in the hour or so since Crater had first captured the loon. Knowing that coyotes and raccoons prowled the beach at night, they decided to place it higher in the dunes than it had been at first. That seemed safer.   

Still, they worried about the loon sitting exposed in the darkness. The bird had not tried to get away from them after they placed it back on the sand. And when they went back to check an hour later, it had not budged. At that point, Kimberly volunteered to take the bird for the night.

Back at home, Kimberly wracked her brain to think what was wrong with the animal. Was it weak from hunger? Knowing that its diet was mainly fish, she offered it the only fish she could – some tilapia filets from the fridge — on a small plate. The loon showed no interest. She looked at the clock and realized that it was 10 p.m. Whatever they were going to do for this loon would have to wait until the next day. She turned the lights out, draped a sheet over the carrier, and hoped it would get some rest.  

The next morning Crater and Kimberly strategized again about the bird. It looked pretty healthy and fiesty, they agreed. They could see no reason to hold onto it any longer. Together they decided to return it to the ocean.

The two friends took the carrier to the beach and removed the loon. This time, though, they let it go at the water’s edge, where the waves were breaking on shore. With furrowed brows and hands on hips, Crater and Kimberly watched as the bird bravely faced the waves and began to crawl towards the ocean. It was not pretty. On five occasions, a wave caught the loon and hurled it backwards several yards towards the beach. Kimberly was reminded of videos she had seen of tiny sea turtles heroicly battling the surf to reach the sea after hatching. The bird did not give up, however. Eventually it was able to take advantage of a lull between waves, reach water deep enough for a dive, and plunge beneath the crashing surf. Kimberly and Crater cheered to see its head pop up thirty yards from shore, well beyond the surf zone.

After a late March sojourn with beach-going humans, the loon, which we had banded the previous summer on West Twin Lake in north-central Minnesota, was back where it belonged — and looking none the worse for wear. We have no idea what brought this nine-month-old to shore.

We got a second, more sobering glimpse into the Great Void in late August 2025.

Battered by stiff winds and high waves from Hurricane Erin, the loon sat within the surf zone on Rockaway Beach in Queens, New York, twelve miles southeast of the Statue of Liberty. Waves crashed over it — even submerging it entirely on occasion. Susan Garman and her ten-year-old son Justin had made a quick trip to the shore to gawk at the surging whitecaps. But when they spotted a large bird that was being pummeled by waves and seemed unable to help itself, their light-hearted jaunt to marvel at nature’s fury took a serious turn.

They hurriedly shed their shoes, waded into the surf, and approached the bird. It looked as bad as Susan had feared it would: dazed, bedraggled, and water-logged. Worse still, the bird showed little fear of Susan and her son when they approached it. “You’re hurt, aren’t you?” she said to the animal, a comforting, motherly tone in her voice. “We are going to help you”.

Yet after she had gathered the bird up, Susan’s concern deepened. She had hoped to feel a smooth, reassuring mass of pectoral muscle when her fingers reached around its chest and belly, but instead, she encountered the sharp protruding keel of its sternum. So it was also emaciated. “Oh, buddy, I am so sorry!”, she whispered. It lifted Susan’s spirits slightly to see that the bird had four bright color bands on its legs. Her mind now racing, she reasoned that the person who had marked this bird would surely wish to help them save it.

She and Justin carried the bird to their home to do what they could. They nestled it in some blankets in the kitchen; it made no objection. Susan Googled “injured bird”, and found some local rehabbers and veterinarians, but no one that she reached could or would help. Justin submitted a photo of the bird to Google Lens to try and identify it. Lens came back with: “The bird in the image is a Common Loon.” “A loon!”, Susan repeated, trying to square her recollection of that glamorous northern species with the unsightly mass of soaked, tousled feathers on her kitchen floor. She and Justin were cheered by their ability to identify the bird they had rescued. They finally seemed to be getting somewhere.

But the loon was very weak and slipping away. “We are here with you”, was all she could muster, her voice softer and breaking from sadness and frustration. Finally, the loon stretched its head forward for a moment, pulled it back again to rest on its chest, and let out its last breath. Crushed by the loss herself, Susan looked for a positive to share with her distraught son. “At least it did not die alone”, she offered.1

We will have to record many more encounters of our young marked loons before we can shed much light on the alarmingly high mortality of loons during their first few years of life. Meanwhile, I am keeping my fingers crossed that other loons of ours who are in need of aid find such generous, compassionate people as these two youngsters did.

1 – We had banded the loon that Susan and Justin found as a chick on Upper Hay Lake, near Pequot Lakes, Minnesota, in July of 2024. So it was just over a year old when it perished. From the work of Kevin Kenow and his team, we know that loons from the Upper Midwest that winter off of Florida make their way up the Atlantic coast to spend the summers of their first and second years of life as far north as the Gulf of St. Lawrence. Thus, this young bird was probably on its way back to the wintering grounds in Florida.

Our paper on the Silver Spoon effect in loons has just been published online. You can read it at:

https://link.springer.com/article/10.1007/s00442-025-05836-8?utm_source=rct_congratemailt&utm_medium=email&utm_campaign=oa_20251124&utm_content=10.1007/s00442-025-05836-8

The top photo is of the loon from Panama City Beach, Florida. Photo by Jim Anderson.

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Following a long summer of capture, marking, and field observation, we have a new tranche of loon data from Wisconsin and Minnesota. The picture in Wisconsin does not change greatly from year to year. There we already had 32 years’ worth of research findings before 2025. But each successive year in Minnesota — where our research began in 2021 — increases our understanding of that population immensely. And with our improved knowledge of Minnesota loons, the status of the loon population across the Upper Midwest is coming into focus.1

Three demographic parameters together dictate whether a population of animals is increasing, decreasing, or stable, These factors are: 1) survival of breeding adults, 2) reproductive success, and 3) young adult survival. Recent measurements have shown us that the Wisconsin population is declining. And we know very well which of these parameters is responsible for the decline. If we compare our growing dataset in Minnesota to the trove of data we have from three decades of research in Wisconsin, we can learn whether or not Minnesota loons are headed in the same direction.

First, let’s look at survival of adult breeders. It should not be surprising that the most important single indicator of population dynamics (i.e. whether a population is stable, increasing or decreasing) is the rate of survival of its adult members. There is good news from the Wisconsin Study Area. The survival rates among territorial females and males both have been stable for the past three decades (Figure 1). This finding implies that once loons reach adulthood, they survive and hold their territories well. The decline that we are seeing in the Wisconsin population, then, must come about because of problems that occur before loons settle on territories.2

Figure 1. Annual survival rates of adult breeders on territories.

What about survival of territorial breeders in Minnesota? From measurements in 2022, 2023, and 2024, it appeared that adult survival in Minnesota might be lower than that in Wisconsin (look at these years in Figure 2, below). However, each year we get a better “read” on these numbers because our sample of loons becomes larger and more representative of the overall population. So the 2025 adult survival numbers are the most reliable ones we have to date. As you can see from Figure 2, there is no evidence for a

Figure 2. Survival rates of adult breeders in Wisconsin and Minnesota from 2022 to 2025. (Sample sizes are shown above each bar.)

difference in survival rates of territorial adults between Wisconsin and Minnesota. Minnesota, like Wisconsin, is seeing good adult survival. Again, this is good news!

Now let’s turn to reproductive success in the two states. Since we learned recently that the silver spoon effect is strong in loons, we know that we must look both at quality and quantity of loon chicks produced to get a good sense of how well a population is reproducing.

First let’s look at quantity. As Figure 3 shows, chick production in each region fluctuates greatly from year to year according to ice out date, severity of black flies, water clarity

Figure 3. Chicks fledged per territorial pair since 1995 in the Wisconsin Study Area and from 2021 to 2025 in the Minnesota Study Area. (Dotted line shows the trend in Wisconsin.)

in July, and other factors. Overall, however, chick production has decreased significantly in Wisconsin during the past three decades. Adult breeders are simply not producing as many offspring now as they did 30 years ago.

While Wisconsin data show a clear decline in number of chicks produced, it is too early to discern a trend in Minnesota. Chick fledging rate simply bounces around too much from year to year to see a pattern. We can say that chick production is at a similar level in the Wisconsin and Minnesota study areas. However, note that 2025 was a banner year for chick production in Minnesota and a poor one in Wisconsin.

Next we need to look at the quality of loon chicks that Wisconsin and Minnesota are producing. Our recent work has shown that chicks that fledge at low weights are much less likely to survive to adulthood and produce chicks themselves than are their heavier peers. Chick body condition has been falling for the past few decades in Wisconsin (see Figure 4, below).

Figure 4. Average body condition (mass divided by age) of chicks in Wisconsin from 1998 to 2025 and in Minnesota from 2021 to 2025. (Trendline shows Wisconsin pattern.)

The five years of data we have on body conditions of Minnesota chicks are not as many as we would like, but the numbers are consistent. Chicks fledge in Minnesota at similar — or even slightly worse — body condition than those in Wisconsin (Figure 4). We can infer that Minnesota is suffering from the same challenging chick-rearing conditions that have plagued Wisconsin (probably declining water clarity).

The third and final piece of the puzzle that we need to understand population dynamics is the survival of young adults. These birds are the breeders of the future that have not yet settled on territories. They range from three to about six years of age.

If you have been following my blog closely, you know that young adult survival of Wisconsin loons has seen the most dramatic decline among the three critical population determinants. That is, adult survival has held steady, and chick production has fallen somewhat, but the return rate of young adults to the breeding grounds has been abysmal — far below what it was a quarter century ago (see Figure 5, below).

Figure 5. Return rates of chicks to the breeding grounds 2 to 4 years after being banded as chicks in Wisconsin. (Data are missing for 2000 and 2007.)

We have been on pins and needles to see if this distinctive and rather alarming Wisconsin pattern is present also in Minnesota. Fortunately, our understanding of young adult survival has grown by leaps and bounds in Minnesota this year. Why? Because: 1) we started banding Minnesota chicks in 2021 and have done so every year since then, 2) most young loons return to the breeding grounds at three or four years of age in adult plumage, and 3) we regularly record identities of these young birds as intruders and loafers within our study areas. Thus, 2024 gave us our first glimpse at young adult survival in Minnesota using the crop of 26 chicks banded in 2021. And 2025 provided an even better window onto young adult survival there, since we could look at the return rate of 64 banded in 2021 and 2022 combined.

What do our findings show so far? In 2021, we banded 52 chicks in Wisconsin. Of these, 7 had returned as of 2025 (13.5%). We marked 28 chicks in Minnesota during 2021, and only one has so far been spotted as an adult (3.6%). For chicks banded in 2022, the numbers that have returned in Wisconsin and Minnesota, respectively, are 5 of 44 (11.4%) and 4 of 36 (11.1%).

These numbers tell a clear story. The percentage of young adult loons returning as adults in Minnesota is well short of that expected in a healthy population (a rate of about 41%). That percentage is also far below what we have seen in the past in Wisconsin (note the return rate in the 1990s and 2000s in Figure 5). In fact, the low return rate of young adult loons in Minnesota closely mirrors the dismal rate in Wisconsin.

In summary, it has taken five years to be confident of how the loon population in the Minnesota Study Area is faring. But our data now show that loons in Minnesota — at least those in Crow Wing and Cass counties, where we work — exhibit the same set of quirky demographic patterns that typify loons in Wisconsin and have set in motion a decline in the overall population there: 1) strong and stable adult survival, 2) poor reproduction in terms of both number of chicks and body condition at fledging3, and 3) a massive and diagnostic plunge in the survival rate of young adults (which are future breeders).

We have work to do.

1Thanks to Sheila Johnston, who took this photo of a molting adult loon on Gull Lake, which is just south of the Minnesota Study Area.

2I know. I just published a blog post in which I mourned the losses of many male breeders in the Wisconsin Study Area. I am still concerned about these losses. But in the long-term, which spans over three decades, adult males and females both have survived well. So I am hoping that the loss of several old, established male breeders this summer in Wisconsin was a blip.

3As noted earlier, it is too soon to tell from our data whether the number of chicks fledged is declining in Minnesota. We will gather those data over time. But we already know that Minnesota loon chicks are fledging in poor condition, just like Wisconsin loons. It is worth noting that the Minnesota Loon Monitoring Program, which has counted chicks across the state since 1994, reports a long-term and statewide decline in chick numbers.

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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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I am a nervous traveller. The day before I am scheduled to leave, I start to worry what could go wrong. Could I miss my flight? What personal items will I forget to pack? Which tasks on my to-do list will I leave unfinished?

So it was two days ago as I drove from the house where I had been staying to meet up with my Minnesota field team before flying home to California. I had spent the morning collecting data on territorial loon pairs — six on Ossawinnamakee, and one each on Fawn and Pig Lake. I relish every moment spent with loons, especially when I am on my own. But anxiety about getting my field work done, entering my data, and tidying up the place before my departure gnawed at me all day.

I tried to work backwards. Arrive at Brainerd Airport at 5:15, so leave from storage box at 4:30. Be at storage box by 4:00 to pack up canoes and check banding supplies for next month. Arrive at tech’s lodging by 2:30 to review field procedures and check in before my trip. Finish entering data in online database by 1:30. Tidy up lodging by 1pm. Leave my last study lake by noon.

When I set off to visit my techs on Ossie, I was still on schedule. As I began to round the hairpin curve on County Road 39 next to the Ossie boat landing, I thought: I just might make my flight. In a brain-staggering moment, though, I spotted an adult loon sitting on the shoulder on the east side of the highway displaying a clear intention to cross. “Oh no!”, I screamed, as I pulled to the side of the road and flicked on my emergency flashers. I ran across the highway and placed myself in the middle of the northbound lane, intending to block any traffic from passing close to the loon. As I crept cautiously toward this adult, I noticed two newly-hatched chicks huddling against it, trying to shield themselves from my view. “Oh no!”, I repeated.

Despite my shock at the loons’ predicament, I understood immediately what was happening. Six hours earlier Keith and Dawn Kellen had given me a tour of the six breeding pairs on Ossie. The Ossie-Muskie Bay pair had stumped us all spring. The Kellens had seen them together early in the year, had seen only one out on the water on multiple occasions thereafter, and yet neither they in their pontoon nor my team in our canoe could find a nest in the far east bay of the lake, adjacent to County 39. The pair had simply vanished. The sudden appearance of an adult and two small chicks told me that they had not nested on Ossie, where we had been looking for them, but on Rat Lake,

Location on County Road 39 where I found the adult male and two small chicks.

across the highway from Ossie’s eastern end. Thus, the Muskie Bay pair was in the awkward situation of seeking to nest on one lake and raise their chicks on another. That ambitious plan set them up for a difficult land crossing.

I had stumbled upon the loon family at the most dangerous point of their overland journey. The adult wailed and tremoloed as I stood in the highway 30 feet away. A southbound car and truck slowed down to rubberneck but continued by despite my frantic waving for help. My mind raced. I could not handle all three loons. If I picked up the adult, its flailing might injure the tiny chicks. Furthermore, the chicks might decide to strike out on their own across the road without their parent to guard them. I was not sure that I could discourage them from putting themselves in harm’s way while holding the adult.

Knowing that the field techs were a few minutes away, I pulled out my phone. “Call Owen”, I demanded of Siri. Owen answered in his calm baritone. But I screeched, “Drop everything and come to the Ossie boat landing. There is a loon here in the road, and I need your help!”. “On my way”, he responded.

While I waited for Owen, more southbound vehicles came by, each carrying a driver wearing a puzzled expression. But no one stopped. As I was debating the odds of getting help from a stranger, the panicked adult abruptly turned, lined himself up with the roadway, and began to run down the highway with wings flapping, leaving his chicks with me. I watched and listened in horror as his feet repeatedly thwacked against the hard pavement during this takeoff attempt and was relieved when he aborted it and skidded to a stop about 40 yards away in the southbound lane.

At that desperate moment, Mitch Carlson arrived in his pickup with his friend, Leo, and stopped in front of the grounded adult. Sensing that the window to save the loon family was closing, I scooped up the tiny chicks and marched hastily in Mitch’s direction (see photo below). He opened his door and looked at me questioningly. “Can you take the chicks?” I asked. “Okay”, he replied quickly, sensing my urgency and smoothly accepting them. He volunteered, “My wife raises chickens!”. I turned my attention to the adult in the road.

After his aborted takeoff attempt, the male loon sits in the southbound lane of County 39 while I approach carrying his chicks. Photo by Mindy Schenck.

Quick, decisive action yields the best results when capturing animals, I have found. When I drew close enough, I lunged at the rearing adult and managed to grasp it. I then folded its wings against its body, held it to my side, and did my best to fend off its bill. Meanwhile, Owen had arrived. I struggled towards the boat landing with him guiding me. Mitch followed with the chicks, while Leo walked alongside, gawking and snapping photos.

The chicks were so small that I was afraid the adult might leave them behind in its haste to put distance between us and himself after release. So I asked Mitch to let the chicks go, waited a moment, and gently

Mitch holds the two newly-hatched chicks moments before we release them at the Ossie boat landing. Photo by Leo Carner.

lowered the adult — which felt like a male based on size and ornery demeanor — into the water at the end of the boat landing. Fortunately, he dove, surfaced quickly, spotted the chicks, and promptly resumed his parenting responsibilities. It was an ample reward for Mitch and me to see them all together so quickly again in the middle of the lake.

The male and chicks reunited quickly after we let them go off of the Ossie boat landing. Photo by Leo Carner.

I will always be a nervous traveler. I do not think one outgrows that. And I need to put a schedule together to convince myself that I can meet a deadline. But perhaps on my next trip I will remember to include 30 minutes of wiggle room for unforeseen events.

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The Silver Spoon Effect occurs when individual animals that experience favorable circumstances early in life — like abundant food — enjoy long lives and produce many offspring when they reach adulthood. In essence, growing up well-fed places a young animal on a track to become successful as an adult.

The Silver Spoon Effect is strong in loons of the Upper Midwest. How do I know this? I have just done a massive analysis of factors associated with return to the breeding grounds among loons banded as chicks. I learned that chick mass (adjusted for age) is the single strongest predictor of both survival to breeding age and breeding success. That’s right: a loon’s mass as a chick accurately predicts how long it will live and how many young it will raise.

This does not mean that a loon chick that grows up without adequate food is guaranteed to die young and raise no chicks. Nor does it mean that a fat, healthy chick is certain to survive to adulthood and have many offspring. After all, it is a statistical pattern. But body mass in chicks is a very strong predictor of lifelong success. The graph below shows the effect.

Loons that did not survive to breeding age tended to be those with low mass as chicks (top row). Loons that survived to return to the breeding ground but never raised young (middle row) tended to be of intermediate mass as chicks. Loons that became successful breeders were mainly those that had been heavy as chicks.

It is hard to know how to feel about the Silver Spoon Effect. On the one hand, it seems cruel. One would love to think that a loon chick could overcome a rough start and turn its life around. But such a turnabout rarely happens. A juvenile that struggles to get enough food in its first month might make its first migratory flight to Florida. However our data show that such a loon has very low odds of surviving beyond its first few years.

On the other hand, loons reared with a silver spoon become the reproductive pillars on which the population’s persistence depends. Take the Pickerel-West male pictured in Hayden Walkush’s photo above. This male — “yellow over white-blue, auric red over silver” (Y/Wb,S/Ar in the table below) — was 8% heavier than average when we captured him on Tom Doyle Lake on August 3rd, 2013 with his parents and younger sister. He was then five weeks old. The momentum that his parents built for him gave him good odds of surviving to adulthood, settling on a productive territory, and rearing young himself. Indeed, he has already fledged six chicks on Pickerel with two different females despite being only eleven years old.

“Yellow over white-blue” is not exceptional. In the table below, you can see the list of all of our recent Wisconsin breeders that were marked as chicks. (Most are males because of the much shorter range of natal dispersal by males.) Pay particular attention to the right-hand column (“% above avg”). A “0” in this column indicates that this loon was of average mass for its age as a chick. If this were a random set of loons, the red numbers would all fall around zero; some a bit negative, some a bit positive. In fact, the table looks like something from Lake Wobegon: almost all territorial breeders in our study area were well above average mass at the chick stage. Sixty-five percent were absolute whoppers — 20% or more above average mass. This is a good illustration of the strength of the Silver Spoon Effect. (The pink-shaded cells show the few current breeders that were of below-average mass as chicks.)

Breeding lake, natal lake, band combination, sex, Chick Mass Index, and % difference from population average for current breeders in the Wisconsin Study Area.

The table shows something clearly. Territory settlers are the cream of the crop. Yes, there are a few overachievers — Harrison Flowage, Manson, Nose, Sherry, Silverbass and Soo. But their small number speaks to the strength of the pattern.

Leaving aside the fascinating and often brutal nature of silver spoons, let’s look at the implications of the pattern for loon conservation in the Upper Midwest. If you recall, the young adult “die-off” that we have found there is the most troubling aspect of the current population decline. Put simply, we are losing the vast majority of all young adults between the time they leave the breeding grounds as juveniles and return to it as adults 2 to 4 years later. This mortality must occur at some stage(s) of the life history of young loons — like migration or winter — that we have not studied well.

Average +/- standard deviation for Chick Mass Index from 1998 to 2020.

Here is the critical point. I have been suggesting that a decline in habitat quality along the migration route or on the wintering ground in Florida might be responsible for the die-off of young adults. But look at the graph above. Chick Mass Index has slid downwards steadily during the past quarter century. This means that the number of loons “fit” enough to survive to adulthood, claim territories, and rear chicks has also declined steadily. So loons are likely not dying because of environmental degradation on the migratory path or in Florida. Rather, loons themselves are of poorer quality than they were 15-20 years ago owing to limited food they received as chicks and can no longer survive the same challenges as well they used to.

Thus, the Silver Spoon Effect forces us to confront an uncomfortable reality: factors on the breeding grounds — during the chick-rearing period — are almost certainly contributing strongly to population decline. We cannot blame Florida.

But the silver spoon has a silver lining. Why? If we can improve lake conditions in Wisconsin and Minnesota so that loon parents can feed their chicks amply each July and August, we can help them raise fit chicks. And those fit chicks will grow up to become robust, successful breeders and strengthen the population.

So the answer, after all, lies in the lakes of the Upper Midwest. And my current push to discover the exact cause of water clarity decline in Minnesota and Wisconsin lakes suddenly takes on even greater importance.

$20,000 Match from a Wisconsin Foundation

If you have already donated to support our work, thank you! If have not yet done so recently, this would be a great time. Earlier this week we learned that a northern Wisconsin foundation will match every dollar raised from other sources up to $20,000. So every dollar that folks are able to donate will add $2 to our 2025 research fund.

DONATE HERE

We would dearly love to take advantage of this opportunity and field a strong research team next year. Thanks in advance, if you can help!

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Almost four years ago, I wrote a blog post about the importance of Florida’s Gulf Coast as a wintering area for loons breeding in the Upper Midwest. I pointed out that 75% of loons breeding in Wisconsin and Minnesota winter along the Gulf Coast of Florida from Pensacola to Fort Myers. And I suggested that conditions in Florida were likely to have substantial impact on the loons we see on our lakes in the north.

My thoughts have returned to Florida of late. Why? Because recent findings suggest that the answer to our greatest riddle might be found there.

Followers of the blog may recall that the single most worrisome pattern related to the Upper Midwest loon decline is the mysterious disappearance of juvenile loons before they reach adulthood. In Wisconsin, the survival rate of juveniles to adulthood plummeted from above 50% to less than 20% between 1993 and 2016, as the graph from our statistical test shows.

The problem has gotten worse since 2016. Only 13 of 209 chicks (6.2%) banded in Wisconsin between 2017 and 2020 have returned as adults. That is a ghastly statistic.

What might be the cause of this massive die-off of young loons? We have good data from the breeding grounds. If juvenile mortality were high during this interval, we would have detected it. Death during migration is another possibility, of course. We do not have good data from that period. But it seems implausible that the varied array of aquatic habitats used by young loons along the migration route have suddenly become a death trap for them.

So it was with increased urgency that I turned my gaze to Florida two weeks ago with our juvenile return data in hand. My hope was to take a second, more thorough look at the likelihood of spotting loons two to four years after we marked them as chicks. I had taken a preliminary glance at this pattern 12 years ago. This time I had: 1) twice as much data, and 2) measurements of physical and biological patterns from ocean water along the Florida Gulf Coast that might help explain the decline. Among physical and biological ocean attributes that I could examine this time were water clarity, temperature, pH, salinity, and concentrations of Chlorophyll A, dissolved oxygen, nitrogen, and phosphorous.

What do the data show? After accounting for observation intensity 2-4 years after banding (which has varied during the study) and location of lake where the chick was banded (because juveniles from central lakes are spotted more often), three variables strongly predict the probability of resighting of a color-marked juvenile loon. In order of decreasing importance, they are:

  • Year — The likelihood of spotting a banded chick as an adult has decreased by an average of 8% from one year’s “crop” to the next. This is the alarming pattern that I seek to understand.
  • Body condition at banding — Chicks that are heavy for their age when banded are much more likely to be resighted as adults.
  • Chlorophyll A level in Tampa Bay in December of the first year — Chicks are much less likely to return if Chlorophyll A levels in Tampa Bay were high in December of their first year (see graph below).

Wait! Does this last finding make sense? First, it is vital to understand that Chlorophyll A is a measure of aquatic phytoplankton — the microscopic algae that can make water appear green to us. A very high concentration of Chlorophyll A can indicate an “algal bloom”, which reduces water clarity and can lead to loss of oxygen and release of toxins. Second, it is important to understand that the negative impact of Chlorophyll A on loons occurs only in December of a loon’s first winter. Return rate of juveniles is not associated with Chlorophyll A levels the month before (November) nor the month after (January). Third, we must be familiar the the migration schedule of juveniles. Juveniles reared in Wisconsin and Minnesota typically reach their Florida winter quarters in late November. Stitching all of this together, the negative impact of Chlorophyll A in December on return rate to Wisconsin suggests that many young loons perish in their very first month on the wintering grounds in Florida if algal levels are high at that time. We would expect these neophytes to be at risk during this period, because they must suddenly find new aquatic prey in wholly unfamiliar habitat. High algal levels add another layer of difficulty to foraging, likely reducing the abundance of prey as well as a loon’s ability to find them.

Of course, this is a hugely important finding. This is the first evidence — to my knowledge — where an occurrence in winter affects a demographic pattern detected on the breeding ground. The effect, moreover, is strong. And the pattern is evident despite the fact that Chlorophyll A data represent only one small part of the winter range (Tampa) that is as far as 350 miles from where some Wisconsin loons spend the winter. We can reasonably surmise that the pattern would be far stronger if we had complete data from all along Florida’s Gulf Coast and could match locations of wintering loons up with Chlorophyll A data from their exact location.

Unfortunately, this striking finding cannot explain the steep decline in juvenile survival rate over the past quarter century. Why not? First, Chlorophyll A levels have remained roughly stable in Florida — maybe even falling slightly — across the two decades or so when juvenile survival has been getting steadily worse. Second, the statistical decline in annual return rate among young adults remains strong even after we have accounted for the effect of Chlorophyll A.

In short, many of our first-year loons do appear to die in Florida, shortly after arriving there. But we are still utterly in the dark with regard to the continuing yearly decline in young adult survival. Young adult loons are future breeders — essential to the stability of the Upper Midwest loon population. It is urgent to learn what is killing them. I will keep looking.

The featured map is from Google Earth. It shows lines drawn between where a loon was banded in summer and where it was recovered or spotted during winter months. Green end points indicate Wisconsin breeders and red indicate Minnesota birds.

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Life is a roller coaster when you pin your hopes to the breeding efforts of a single loon pair. If the male arrives in late April and the female does not show until early May, you fret. If the pair places their nest on the mainland rather than an island, you grit your teeth and prepare for four long uneasy weeks. If black flies hound the male and female on the nest, you curse the flies. And if two chicks hatch after the long ordeal of incubation, you weep sweet tears of joy.

During the decades she has spent pulling for the loons on Deer Lake in Wisconsin, Shirley Lamer has experienced plenty of ups and downs. Deer Lake had three straight years of chicks from 2003 to 2005*, but historically chicks have been more the exception than the rule. In fact, chicks have only fledged from Deer in three years since 2005.

Nesting habitat is part of the problem. It is not abundant on the 150-acre lake. Small marshy coves at the north end are tempting for a nest, but they offer no opportunity for an off-shore site. A permanent island halfway down the west side is, in fact, the most obvious spot. But even there danger lurks. The water between the island and the shore is shallow. Predators apparently reach the island easily when the lake level falls.

This year, all of Deer Lake’s past breeding woes are forgotten. On about June 9th, Sharon and Lonn** (named for Shirley’s parents-in-law) hatched two healthy loon chicks. Week after week Shirley followed the chicks’ development from fuzz ball to adult size. She giddily posted photos and videos of the loon family on Facebook when she encountered them in her kayak or they foraged near her dock. One of her chicks, which we banded in early July, stayed on the lake until the first week of September. The other remained on Deer until mid-September before flying off to feed elsewhere.***

But Deer’s two chicks were not the only cause for excitement on the lake this year. Two juveniles from nearby lakes landed in Deer. Knowing that we marked most of the chicks in the neighborhood, Shirley leapt into her kayak when she spotted these young visitors. Her efforts have paid off.

On September 11, Shirley found that one of two juvies banded on Crystal Lake had landed in Deer to feed. The Crystal juvie foraged loosely with the remaining Deer juvenile and Lonn, the Deer male. Four days later, Shirley identified the Jersey City Flowage chick as a second visitor. While the JCF juvie has gotten no food from Lonn — despite efforts at calling and following him — the juvie apparently found the fishing productive. He remained on Deer on September 16th also.

You might have noticed that I called the JCF juvie “he”. The JCF juvie is clearly a male. How do we know this? Because — as you can see from Shirley’s video below — he

Jersey City Flowage juvenile emits a truncated yodel while visiting on Deer Lake, Wisconsin on September 15. Video by Shirley Lamer.


yodeled during his visit. This is not the first time we have seen a juvenile loon give the introductory note of the male territorial call. In fact, Paul Strong just e-mailed me that the fledged chick on Long Lake in our study area did so as he watched from his canoe a few days ago. And we have observed chicks as young as six weeks of age emit truncated yodels after being released following banding. So we can see that young males — at least some young males — begin to yodel during the first three months.

Between fretting over the nest location, worrying about black flies, rejoicing over the successful hatch, and tracking the growth of chicks over weeks and months, it has been a busy summer for Shirley. She might have been forgiven if she had wrinkled her brow and left it at that when foreign juvies started arriving on the lake for snacks. Thank goodness she kept at it. Her tireless and meticulous loon observations have shed light on both pre-migration feeding patterns of young loons and a truly unknown pattern — behavioral development of the territorial call.

* “Clune”, Linda Grenzer’s and my favorite male loon, first settled on Deer in 2003. He was then only 5 years old. He and his mate reared chicks there in 2003, 2004, and 2005. But after a run of failure from 2006 to 2008, Clune evicted the male on neighboring Muskellunge and settled there.

** It is Lonn (Sharon in the background) who is pictured in Linda Grenzer’s beautiful featured photo.

*** We have learned quite a lot about the movements and feeding patterns of juveniles in the fall months.

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Loon pairs experience many setbacks during the course of a breeding season. Black flies drive them off of nests in May. Eagles take chicks. Intruders force them to expend energy in territory defense or even evict them. Rainfall clouds the water, making it difficult to find food for chicks. It is largely a pair’s ability to bounce back from such adversity that determines how successful they are at fledging young.

The loons at Big Trout-Far West, part of the Whitefish Chain, faced more than their share of challenges this summer. All seemed good in May, as the pair shared incubation duties on their two eggs (see photos above by Karl Olufs*). When they hatched two healthy chicks on June 9th, the veteran male and female breeders seemed poised for a fruitful year. But their luck turned. On June 12 a freak storm dropped golf-ball-sized hail to across much of the Minnesota Study Area. One three-day-old chick took refuge under a camp’s pier, while the second remained out in the chop. Following the storm, the exposed chick was found dead on shore, and only its sibling remained. In a poignant moment, one of the parents left the water and sat on shore beside the deceased chick, before returning to tend its surviving sibling.

Three-and-a-half uneventful weeks passed, and the surviving chick grew. On July 6th, though, the male, who had been healthy the day before, died suddenly and violently, a likely victim of a boat or jetski collision. For a few days, the female cared for the chick alone. But a new unmarked male soon noticed the lack of a male defending the territory and joined the female. Unwilling to rear a chick not his own, the new male grabbed the chick, shook it violently — as a horrified lake resident looked on — and killed it. In a month’s time, the original family of four had been reduced to one.

When Richard Rammer and I visited the Far West pair on July 26th, they were resting quietly in their marshy cove, as if in recovery. The female cooed repeatedly to her new mate, trying to coax him to search for a nest site. He sat quietly a few meters away, unmoved. There was something touching in the female’s stubborn unwillingness to accept defeat. Battered as she was by misfortune, she was looking forward — seemingly determined to lay the groundwork for a successful 2025 breeding season.

As horrid a year as the Far West pair had, they are only one pair. Elsewhere on the Whitefish Chain, the news was better. The pair at Island-Channel, which adopted a doomed chick in June, still had both their biological chick and the fostered one. Despite the apparent vigor of both chicks, I had nagging concerns. Was the biological chick getting more food? Were the chicks still bickering? The scale told the story: both chicks weighed in at a strapping 2.42 kilograms on the night of July 20th, when we caught the entire family.** Their future looks bright. Good news emerged too from a second pair on Island Lake, which abuts the Island-Channel territory. There an unmarked pair have raised a chick to five weeks of age and are likely to fledge it.

Even on Big Trout, where boat traffic is constant and rapid, a glimmer of hope emerged. Big Trout-Central, a few miles east of the ill-fated Far West pair, has raised a chick that recently turned five weeks of age. If it can dodge boats, jetskiers, and eagles for the rest of the summer, it will be the first fledgling from that territory since 2020.

Cross and Rush Lakes each contain three breeding pairs with chicks. The total of eight chicks between the two lakes is mediocre, considering the dozen territories they support. Still, among the chicks is a singleton produced by an all-new Rush-Boyd pair that bounced back from a chickless year in 2023.

Daggett Lake had an off year. Neither the Northeast nor Southwest pair hatched eggs, while the Channel pair hatched two healthy young from an island but lost them in the first two weeks. On the other hand, the Little Pine-Dream Island pair is enjoying their fourth consecutive productive season, raising two enormous independent chicks just north of the channel from Daggett. The news is also good from Pig Lake, where a new pair is raising two huge chicks after an off-year in 2023. The pair on Bertha, chickless for the past three years or more, also has two gigantic eight-week-old chicks. Sadly, the Upper Whitefish-Steamboat pair lost two small chicks in the same freak storm that cost one of the Far West chicks its life. But two of four pairs on Lower Hay (Northeast and Southeast) have chicks that are fit and strong. By raising a chick this year, the Northeast pair broke a slump of at least three years without young.

Loons in the Outing/Fifty Lakes section of the Minnesota Study Area, like those on Cross and Rush lakes, were only moderately productive. Roosevelt and North Roosevelt, between them, yielded only two fledged chicks this year. West Fox and East Fox pairs looked good early in the year. But the disappearance of the East Fox-South male resulted in loss of two chicks, in spite of the heroic efforts of the female to rear them alone. Furthermore, late loss of a large chick on West Fox-Stone Man whittled down the productivity to three chicks between the two lakes. Eagle Lake, similarly, yielded only one fledged chick. A mere two chicks emerged from Eagle, Kego, Butterfield, and Mitchell lakes combined this year, in contrast to the six produced in 2023.

There was a pleasant smattering of chicks on small lakes in the Crosslake region. Goodrich-West and -Southeast pairs both raised chicks successfully, and two new breeders on O’Brien beat all odds by hatching a late chick there. Kimble-East was a washout, but Kimble-West, Clear-North and -South, Star, Big Pine, and Grass lakes together raised eight chicks.

Lakes in the southwestern portion of the study area had an especially impressive breeding year. Ossie pairs raised five chicks in all. Pairs on Upper Hay, Nelson, Sibley-North and -South, Fawn, West Twin and the Cullens produced chicks at above-average rates, as did those on Roy-North and Roy-South and Nisswa. Pairs in the Upper Gull area did particularly well, including Mayo Creek, Boathouse, Bass Lake and Margaret-North pairs.

In short, the cruel summer at Big Trout-Far West did not typify the breeding season overall for the Whitefish Chain or the Minnesota Study Area as a whole. Stepping back to view the season from space, it was a decent breeding year. Low and short-lived populations of black flies early in the year helped get the season off to a solid start. Alas, the abundant rainfall we have had this spring and summer means that we cannot count on the continued paucity of these pests in 2025. For the moment, though, let’s shrug off the disappointment at Big Trout-Far West and enjoy the rather productive breeding year for loons in central Minnesota!

* Thanks to Karl Olufs and his sister, Janet, who paddled her kayak out to meet us on July 26th to relate the saga of the Big Trout-Far West pair.

** The male of the Island-Channel pair is an interesting loon in his own right. Hatched in 2016, he is among the handful of loon chicks marked with silver numbered bands by Kevin Kenow of USGS. Upon his capture, we read the number etched into his band and discovered that he was raised on the Big Island territory on Upper Whitefish in 2016. Thus, he is a whippersnapper at 8 years of age. He is the first known-age loon to settle in the Minnesota Study Area.

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Sibling rivalry is a fascinating but intellectually thorny behavior pattern. Why would a young animal hurt its own flesh and blood? To put it scientifically, why would an animal harm its full sibling when that sibling shares half of its genes and when the ultimate goal of animal behavior is to increase the abundance of one’s genes in the next generation?

But normal rules do not apply when food is limited early in life. If the food supply is inadequate to keep all members of a sibling group alive, then the only sound evolutionary strategy for each sibling is to battle mercilessly and become a survivor.

Such is often the case in loon families, especially those living on small lakes. Even with only two chicks to care for, loon parents are all out to keep them alive. This scenario creates the haves — chicks that hatch two days before their siblings and use their size advantage to pummel them and gain a greater share of the limited food that parents can find — and have-nots.

What of the have-nots? To avoid beatings from an aggressive older sib, a typical younger sib lags behind its family and, as a result, receives fewer feedings. It becomes weaker over time, is less able to defend itself, suffers more beatings, and begins to avoid its family altogether. Unable to escape this downward spiral, most beta chicks perish from starvation. Some undoubtedly fall prey to eagles.

But not all starving beta chicks die quietly on their home lakes. Sometimes a chick in such dire straits abandons its home and kin and strikes out over land in hopes of finding a new family of loons that will feed and protect it. If it sounds preposterous that a weakened, helpless loon chick would trek through the woods in hopes of being welcomed by a foreign loon family, it is. Only the prospect of certain death at home could induce a chick to make such a reckless, fanciful journey. And yet such “chick odysseys” happen commonly at this time every year.*

We are four weeks into the chick-rearing period in both Minnesota and Wisconsin study areas. So this is the time when a small cohort of starving second-hatched chicks from small lakes across the Upper Midwest are abandoning their abusive older siblings to seek a better life elsewhere.

A two-week-old chick in north-central Minnesota took this desperate approach. A good samaritan stumbled upon the brown puffball on a roadside and carried it a rehabber. But the rehabber had no future to offer the chick. Only loons can raise loons. In fact, only adult loons who currently have chicks of their own are (sometimes) willing to accept these waifs.

It is a chancy business to match a parentless chick with a foster family already rearing a chick. The chief danger is lack of acceptance by the biological chick. If the natural chick attacks the chick you are trying to add to the family, you are back to square one. Folks who attempt fostering of this kind report a success rate of about 35%.

The loon pair of Island Lake on the Whitefish Chain had a single two-week-old chick — very close to the size of the chick found on the roadside. As shown in the video below, the homeless chick quickly joined and bonded with the Island family. After an initial tussle with its new sibling ended in a draw, the biological chick seemed to resign itself to the new addition. Both chicks remained peacefully together this afternoon, three days after the introduction.**

Introduction of rehabbed chick at Island Lake, Whitefish Chain, Minnesota.

We have no idea what the future holds for the adopted chick. Starvation, predation, a boat strike, or fishing entanglement might end its life before it reaches fledging age. Yet a chick that was a longshot to survive two days ago is suddenly ensconced with a protective new family. And this former have-not now stands a decent chance of reaching adulthood. It is hard not to feel good about that.

* Though these journeys are the most desperate of long-shots, they do not always fail. In fact, we had one case where a chick that fled across land reached a new lake, gained two new siblings, and lived happily ever after.

** The top photo shows the Island Lake pair and their two chicks as of June 28th at 1pm. Evrett Fiddian-Green, who took this photo, reports that both chicks are being fed by the parents. Most important, the chicks are not fighting.