Rescuing Iced-In Loons

If there’s too much open water and the loons are in good health (as seen here on Lake Winnipesaukee in New Hampshire in January 2022), the birds can easily dive to evade capture – so the first part of many rescues is simply watching and waiting. With the help of Nordic skaters, LPC biologists monitored these loons for a full week before conditions aligned for a rescue attempt. Photo by Harry Vogel / LPC.

Loon biologists have traditionally worked three field seasons: spring, when common loons return to northeastern lakes, as if by magic, within a day or two of ice-out; summer, when nesting and chick rearing take place, along with a flurry of associated research, monitoring, and management activities; and fall, when the birds depart for their open-ocean winter territories and the biologists stow away nest rafts, kayaks, signs, and other tools of the loon monitoring trade for safekeeping.

Over the past two decades, however, a fourth season has emerged. Winter had long been reserved for indoor pursuits (for the biologists) and saltwater fishing (for the loons), but staff and volunteers from conservation organizations such as the Adirondack Center for Loon Conservation (ACLC), the Vermont Center for Ecostudies (VCE), and New Hampshire’s Loon Preservation Committee (LPC) now find themselves skirting snowflakes to rescue distressed loons on inland lakes from November through early March.

For LPC, this fourth season began in earnest on Valentine’s Day 2007, when a group of snowmobilers found dozens of loons stranded on the ice in the middle of Lake Winnipesaukee, New Hampshire’s largest lake. Tragically, by the time they were discovered, most of the birds had frozen to death, but LPC was able to rescue and release five of them along the New Hampshire coast. Since that time, LPC has rescued more than 70 iced-in loons.

The physiological features that make loons superbly suited for swimming and diving also make it difficult for them to take flight in less than 100 yards of open water. The Loon Preservation Committee rescued this juvenile loon from Chase Pond in Wilmot, New Hampshire, where it was trapped in an area of open water just 15 feet in diameter. Photo by Marc Beerman.

Although the ACLC had undertaken occasional winter rescues of individual juvenile loons dating back to the 1990s, they received their first report of multiple iced-in adult loons, trapped together on Lake George, in 2013. They saved those five birds, then went on to perform five more ice rescues in a single week during a sudden cold snap in 2016. Incidents of iced-in loons have since become so frequent that the ACLC now schedules an annual training with their local rescue squad, including time on the ice in survival suits.

In Vermont, 2016 was also a significant year for ice rescues. That February, VCE loon biologist Eric Hanson spent three full days with a team of volunteers retrieving eight loons from an ever-narrowing opening in the ice on Lake Champlain. (Sadly, one additional bird was found dead, trapped under the ice. Another dove during the rescue effort and never resurfaced, underscoring the extremely delicate nature of these operations.) Hanson estimates that he now gets 6 to 12 calls about iced-in loons every year.

Why Do Loons Get Trapped?

For the most part, loons that nest on northeastern lakes and ponds depart inland waters in late fall for the New England or mid-Atlantic coasts. There, they live the life aquatic, bobbing in the surf and diving for marine delicacies such as menhaden and flounder until spring. While afloat, they undergo a significant simultaneous (or “catastrophic”) molt, shedding all their well-worn wing feathers and re-growing strong new feathers in their stead. This process prepares the birds for spring migration, but renders them incapable of flight for about a month while the feathers fill in.

If the area of open water is too large to easily net loons from nearby ice edges, rescuers may use tarps to help corral the birds. Here, a team of volunteers led by Eric Hanson of the Vermont Center for Ecostudies (VCE) prepares to deploy a tarp during an ice rescue on Lake Champlain. Photo by Phyl Newbeck.

Amid boundless open water for fishing and with no breeding territories to scout, establish, or defend, wintering loons usually have no need to fly. However, some loons linger longer on inland lakes – and find themselves in trouble when ice starts to creep close.

The very features that make these pointy-billed piscivores so exquisitely suited for swimming and diving – heavy bones and disproportionately large, webbed feet, with outwardly angled legs situated far back on their bodies – also make it difficult for them to take flight. To achieve liftoff, they typically need a 100-yard runway of open water. When ice shortens this aquatic airstrip, they can become trapped.

While some loons may overstay their freshwater welcome due to injury, disease, lead poisoning, or – for juveniles – inexperience, even perfectly healthy, fully feathered adult birds can get caught unawares by cold snaps and swift-forming ice.

And once they’re in the midst of a catastrophic molt and lose their ability to fly, even a winter thaw won’t free them.

Whatever the reason, when loons find themselves surrounded by encroaching ice, they need help. “They’re doomed if we don’t rescue them,” said John Cooley Jr., a senior biologist with LPC.

How Rescues Work

Conservation groups are still exploring the best ways to aid stranded loons, efforts Cooley described as “evolving and collaborative.” No two rescues are the same, as each involves a unique combination of factors. Weather, location, staffing, equipment, ice thickness, distance from land, and the health of the individual loons all play a role, and timing is everything. If there’s too much open water and the loons are in good health, they can easily dive to evade capture. If there’s too little, they become vulnerable to starvation and predation by eagles. The first part of many rescue attempts is simply watching and waiting for the ice aperture to shrink just enough, but not too much.

Biologists utilize two types of nets for capturing iced-in loons: gillnets (top), which typically require at least two people in proper safety gear to operate; and heavy-duty, long-handled landing nets (bottom), which can be used solo. During this complex rescue of 10 birds on Lake Winnipesaukee in January 2022, LPC biologists John Cooley Jr. (in yellow), Tiffany Grade (in white hat), and Caroline Hughes (in blue hat) employed both. Photos by Robert Kozlow.

“We evaluate each situation very carefully. There are certain situations when we can catch the birds, and others where we can’t,” said Nina Schoch, executive director and director of science and conservation at the ACLC.

Human safety is also a critical consideration. While some programs have cold-water safety gear and year-round staff, others have yet to invest in – or simply can’t afford – such resources.

“I tend to let things play out a little bit longer, mainly for safety reasons,” said Hanson, who does not have access to a survival suit and must therefore wait for the ice near distressed loons to grow thick enough to safely support his weight. (VCE plans to purchase cold-water survival gear this winter.) “In the meantime, I just hope that the loons are able to keep the hole open by swimming, and that an eagle doesn’t get there first.”

Waiting has its advantages. Hanson knows of birds that have defied the odds by eventually taking flight from just 20 feet of open water, their feet scraping the ice as they worked to gain elevation. One of them crash landed at the other end of the lake, waddled into a nearby stream, and was easily rescued from there. (No survival suit necessary.) Two were motivated by the presence of a bald eagle standing at the edge of the ice, eyeing them hungrily from mere feet away. “If they’ve got the gumption and the energy,” said Hanson, “sometimes they can do it.”

But not always. Last year, while Hanson waited for the ice to thicken, eagles predated three of the loons he was monitoring. Others simply disappeared without a trace.

So, when a rescue attempt seems reasonably safe, with decent odds of a good outcome, Hanson and his colleagues move forward.

Methods vary, and the area of open water, thickness of the surrounding ice, number of loons, and number of rescuers must all be taken into account when formulating a plan. When possible, the rescuers will simply walk out onto the ice, pulling a jet sled, canoe, or small jon boat behind them. On large lakes such as Winnipesaukee, which covers approximately 70 square-miles, other transportation may be required.

On Chase Pond, LPC senior biologist John Cooley Jr. disentangles a rescued loon from a gillnet. Depending on the site and the circumstances, rescuers may transport loons to shore via jet sleds, canoes, or jon boats (pictured). Photos by Marc Beerman.

LPC regularly partners with local fire departments, whose expertise with retrieving snowmobilers and fishermen from unreliable ice comes in very handy. During a two-day, six-bird rescue on Lake Winnipesaukee in February 2023, for instance, the Tuftonboro Fire Department sent an airboat and three firefighters to help biologists traverse thin ice more than a mile from shore.

Once rescuers are on site, the first step is to evaluate the amount of open water. If the opening is too large for biologists to net the birds from nearby ice edges, the team may use tarps, secured with ropes and/or ice screws, to help corral the loons.

There are two options for nets: heavy-duty, long-handled landing nets, which a single rescuer can handle; and gillnets, panels of netting that are stretched and dragged across the water, and which typically require at least two people in proper safety gear to operate. Some teams employ both.

Capturing the birds can take many hours and sometimes requires multiple attempts over the course of several days. Once they have the loons in hand, biologists disentangle them from the nets, place the birds in boxes or bins, and tow them back to shore.

In Vermont, if rescued loons appear healthy, Hanson will bring them directly to an open-water section of Lake Champlain for release. If a loon is too weak for immediate release, he’ll take it to the Vermont Institute of Natural Science’s Center for Wild Bird Rehabilitation for evaluation and care.

In New Hampshire, LPC typically collects blood samples from all rescued loons before release to check for lead poisoning, anemia, and signs of infection. They also take the birds to a consulting veterinarian for x-rays, in order to rule out any internal injuries and the presence of ingested fishing tackle.

If the loons are given a clean bill of health, LPC biologists band them, drive them to the coast, and release them back to the wild at the edge of the sea. If the loons are sick or underweight, they are transferred to Wings of the Dawn Wildlife Rehabilitation Center in Henniker, New Hampshire, for feeding, care, and observation. In the past, LPC has also drawn on the specialized expertise of a small-world network of other loon rehabilitators in New England, including Kappy Sprenger in Bridgton, Maine, and Diane Winn and Marc Payne in Unity, Maine.

VCE loon biologist Eric Hanson releases a rescued loon on Lake Champlain. Although conservation groups in Maine and New Hampshire release winter-rescued loons along the coast, in Vermont and New York they’re often brought to an open-water section of Lake Champlain. Photo by Phyl Newbeck.

The goal is to get the loons back on open water as soon as possible, so in most cases the birds are released once they’ve demonstrated that they can swim and fish properly, typically within a day or two of rescue. Occasionally, however, Mother Nature has other plans, such as December 2023, when rescuers retrieved a healthy iced-in loon from Province Lake in Effingham, New Hampshire, but could not release it until a Nor’easter subsided, four full days later.

For loons that have ingested lead fishing tackle – the leading cause of adult loon mortality in New Hampshire – rehabilitation can take weeks and often requires chelation therapy (injections of medicine that help flush lead from the loon’s blood). During the summer months, lead-poisoned loons rarely survive, even with treatment, but in a surprising and hopeful development, LPC is finding that winter instances of lead poisoning seem to respond better to chelation.

Uncharted Waters

Although iced-in loons have been documented as far back as 1874, when a hunter reported in Forest and Stream magazine that “it appeared as if all the loons in the country had assembled in one small hole in the ice” in Calais, Maine, modern-day biologists have noted a marked increase in the need for winter loon rescues in recent years. The exact reasons for this rise are unknown, but several factors may be at play.

First, it’s possible that increased winter recreation – along with a greater public awareness of the availability of qualified rescuers to respond to loons in distress – has simply led to more reporting of a common occurrence that had largely gone undetected in the days before ice sailing, kiteboarding, and Nordic ice skating grew in popularity. When it comes to notifying LPC of loons that might need assistance, Cooley said, “Nordic skaters have become real allies.”

LPC senior biologist John Cooley Jr. runs bloodwork from 10 loons rescued together on Lake Winnipesaukee in January 2022. The analysis showed slightly elevated lead levels for one bird, which was given chelation treatment at Wings of the Dawn Wildlife Rehabilitation Center in Henniker, New Hampshire. Photo by Harry Vogel / LPC.

An increase in the loon population also may be a factor. While the species continues to face many challenges, there are many more loons breeding each summer in the Northeast than there were 20 years ago. With more loons on the landscape, perhaps an uptick in distressed individual birds is inevitable.

Of greatest concern is the threat of climate change and whether some of the climatic cues that prompt loons to migrate in the fall (air temperature, water temperature, ice encroachment) are coming too late in the year, when the birds are mid-molt and therefore unable to fly away – a phenomenon Schoch calls a “molt-migration mismatch.” This mismatch has factored into a number of recent rescues on larger lakes in New Hampshire and New York that did not freeze solidly until midwinter, when the molt was well underway. (According to Hanson, this is less of an issue in Vermont, where most lakes still freeze over by January – at least for now.)

“We think we’re going to see more of these ice rescues over time, and we also expect that things will continue to change over time,” said Griffin Archambault, the ACLC’s research biologist.

The Long View

Thanks to many years of intensive monitoring and management, New Hampshire now has close to four times more territorial loon pairs than in 1975, when LPC was founded. In 2005, with recovery goals met, Vermont removed loons from the state’s endangered species list. In New York and Maine, breeding loon populations are currently considered stable or increasing – but they’re not out of the woods.

Loons continue to face many threats, including shoreline development that encroaches on nesting habitat, recreational pressure that stresses loon families, exposure to lead and other contaminants, and fishing line entanglement. Climate change also looms larger with each passing year. In addition to the phenological mismatch caused by warming winters, extreme summer heat creates physiological stress on nesting birds that can lead to nest abandonment.

Rescuers bring injured, sick, or lead-poisoned loons to wildlife rehabilitation centers, where the birds remain until they demonstrate that they can swim and fish properly. This loon, rescued from Martin Meadow Pond in Lancaster, New Hampshire, in 2014, passed muster after a short stay in the rehabilitation pool at Avian Haven in Freedom, Maine. Photo by Diane Winn / Avian Haven.

Higher temperatures also contribute to the prevalence of illnesses such as avian malaria and fungal diseases. And more frequent torrential rain events – another consequence of climate change – flood nests and decrease water clarity, affecting loons’ ability to hunt for themselves and their chicks.

The average loon pair fledges just one chick every other year, but loons can live upward of 30 years, so losing (or saving) even a handful of adults can make a real difference in the long-term.

Banding data have also shown that winter-rescued birds can – and do – successfully return to their breeding territories. In one high-profile, multiday rescue in January 2022, LPC staff saved a total of 10 loons from Lake Winnipesaukee, releasing all of them along the New Hampshire coast. The following spring, band re-sightings confirmed that six of those birds had returned to lakes in northern and western New Hampshire. Four were part of breeding pairs, and two added to the state’s loon population that summer by successfully fledging chicks.

In addition to buttressing populations, winter loon rescues also contribute to biologists’ understanding of the species. When they’re out to sea, loons are almost completely inaccessible to researchers, making winter a largely unstudied time in the lives of these agile waterbirds. The new fourth season thus holds incredible potential not only for better understanding loons across their full life cycle but also for informing future conservation efforts.

“It’s a humane response to each individual loon, but it’s also a chance to learn,” Cooley said. “With each loon that we rescue, we learn something new.”

And, of course, loon rescues don’t just affect loons. With their primordial wail, striking plumage, and highly visible presence on lakes that people hold dear, loons inspire extraordinary devotion. Summer or winter, lake lovers become invested in “their” birds – and deeply distressed when they see these beloved wild neighbors in peril. At a time when biodiversity loss and the climate crisis weigh heavy on so many hearts, loon rescues offer a tangible expression of hope. “Rescues touch everyone who is involved, and everyone who hears about them,” said Hanson. “It’s amazing what that does to people.”

View the accompanying Web Extra: Loon Rescues on Ice