Crazy for Loons

A summer presence on Canadian lakes, loons and their soulful songs are deeply immersed in this country’s collective identity

With its iconic appearance, haunting calls and cross-country presence, the loon has become a beloved symbol of Canadian summer. It is so emblematic of this country that it lends its identity to the one-dollar coin and recently beat the snowy owl and the Canada goose by a landslide in a vote for Canada’s national bird. “They’re a symbol of our wilderness,” says Kathy Jones, volunteer manager of the ongoing Canadian Lakes Loon Survey being conducted by Birds Canada. Not surprisingly, one of the very first Hinterland Who’s Who videos, created in the early 1960s and rediscovered only a few years ago in a private collection in Vancouver, features the common loon and its distinctive calls.

The black-and-white, spotted-and-striped common loon, also known as the great northern diver because it spends long periods underwater hunting for fish or evading its enemies, has a unique physiology: small wings and a heavy body due to solid bones (many birds have hollow bones) that reduce buoyancy. The loon’s muscular legs, positioned

far back on the body, splay out to the side when paddling, making it an extremely agile and strong swimmer. Before diving beneath the surface — as deep as 60 metres in a few seconds and for as long as three minutes — a loon compresses itself, emptying its lungs and forcing out any air trapped in its feathers. To stay so long below the surface, it has a remarkable physical reflex that slows the heart, decreases oxygen demand and relies on a metabolism that has evolved so that muscles can function anaerobically until the bird resurfaces.

Experts disagree on why adult loons’ eyes seem to glow red: one school maintains that a red retinal pigment filters light beneath the water’s surface, affording excellent vision in pursuit of prey in murky depths; another theory suggests it has to do with being attractive to loons of the opposite sex, which is supported by the fact that their eyes become dull when mating season ends.

Sharp rearward barbs in the loon’s sturdy beak and on its tongue enable it to latch on to a slippery fish before swallowing it whole while still submerged. A family of four will eat as much as 500 kilograms of fish over the summer.

The smallish wings, well suited to underwater travel, mean the loon is unable to glide or soar in flight and needs plenty of runway just to take off. That’s why at launch you see a loon flapping and “running” on the water’s surface for quite a distance, trying to develop extra lift by heading into the wind. (It is also why loons tend to prefer nesting on long narrow lakes with longitudinal prevailing winds.) Despite the challenges, once airborne, loons can reach speeds of more than 100 km/h and travel for several hours straight, impressive given that they cannot glide, soar or otherwise rest in mid-air.

Loons are migratory. More than half of the world’s 620,000 adult loons come north or head inland in early spring to breeding sites across Canada, the majority to Ontario and Quebec. They head south or to the coasts in late October or early November. Loons in the West head for the Pacific coast, settling anywhere between the Aleutian Islands of Alaska all the way to Baja California in Mexico. Those in central Canada tend to winter on the Gulf of Mexico or the Florida panhandle. Loons from eastern Canada migrate to the Atlantic coast, anywhere from Newfoundland to Florida.

Life on land is hard for the loon. The aft position of its legs means it is ill-suited to walking: unable to cover significant distances, a loon even has difficulty just standing upright (you might see a loon leaning forward on its chest to maintain balance). In fact, the name “loon” is derived from the Swedish and Icelandic words for “clumsy.” Loons go on land only to mate and to nest. For this reason, nests are positioned right by the water.

As Jones points out, the fact that loons live on the water makes it easy to appreciate them. It also makes them easy to hear. Loons have four distinct calls for different occasions — the best-known is probably the wail, a long call used to find an absent mate. (See sidebar “Four Songs of Summer” on page 20.)

For many Canadians, loon calls have come to evoke summers of lake trips and cottage vacations, of time spent outdoors and at ease. Canadians love their loons, and they’re willing to do the work to protect them. The Canadian Lakes Loon Survey started in 1981 as an Ontario-specific operation, Jones says, and expanded to a Canada-wide annual survey in the early 1990s. She has been running the program since 1995. Over that time, she has seen the children and even some grandchildren of the original survey participants take on the duties of checking up on local loons. Some families have been with the program longer than she has. It now has between 600 and 700 volunteers. (At press time, it was suspended temporarily due to COVID-19 as people maintained social distance and stayed home. But the association website says the program will be brought back when it’s safe to do so.)

“It’s a really cool survey because you can do it in conjunction with your play on the lake,” she says. When out at the cottage, camp or cabin enjoying things like kayaking, fishing or lounging lakeside, it’s easy to check on the loons, she says.

“We ask volunteers to go out and identify the loons at three stages of life,” Jones says. In June, participants check if their loons have come back. Loons aren’t totally monogamous, the way geese are, but they do remain paired for multiple years. Those pairs return to the same lakeside nesting sites again and again, and good nesting sites are the subject of fierce and often bloody competitions.

If the couple hasn’t returned, that might mean the worst has happened and one or both have died. Then again, they might have been pushed out. Loon life is like a soap opera, says David Evers, executive director and chief scientist at the Biodiversity Research Institute and leader of its loon program. “Male and female loons on a territory are bonded to that territory,” Evers says. The loons pair up with one another, sure, but the territory is the primary thing. Because loons need spots close to the water’s edge, on a given lake, good nesting sites are limited. “Loons that are not on a territory will fight a territory holder,” he says. “It’s always

a same-sex conflict — a male fights a male, a female fights a female.” The winner takes the territory — and the mate.

Good territories are hotly contested. “If you follow individuals over time, you find that on average they’re on a territory about six or seven years,” he says. “Eventually, they tire out and are outcompeted by another territory holder.” When that happens, the loons are like defeated streetfighters — they join a band of common loons that sort of drifts from site to site, honing their skills and gaining body mass. Then they challenge territory holders for a new territory, and the whole cycle starts again.

All of this unfolds before the next survey check-in: central and eastern Canadian participants look in again around the Canada Day weekend (a popular cottaging time in any case) to check if the nest has hatched. In western Canada, the hatch schedule is a week or two later, Jones says.

A third check-in takes place in August to see if the new loons have made it to six weeks of age. If the birds have not died of exposure, undernourishment, drowning or attack by an invading loon or other predator, Birds Canada has “considerable confidence that they’ll survive in the lake and fledge in the fall.”

“We have them collect those three numbers and populate a form and send it back to us,” Jones says. That data has helped scientists and policymakers understand the last 40 years of unprecedented change and pollution on Canada’s lakes. Because of their high visibility, their site loyalty and the fact they eat huge quantities of fish, loons are a great bioindicator species: their well-being reflects the larger environmental problems that plague both their home lakes and the wider systems these lakes make up. Despite decades of concerted action on acid rain and mercury reduction, pollution continues to be a significant threat, affecting loons’ reproduction and lifespan.

Migration presents other threats. When loons stop in a lake for a day or two to refuel and rest on their way to and from breeding sites, it’s called staging. Migration always has perils for birds — starvation, predation and deadly encounters with human infrastructure being three — but another, growing problem is having a huge impact on staging loons today, Evers says. Botulism.

Botulism is a neurotoxin produced by a bacterium, and it “outright kills a bird. After it gets it in its system, it kills it within a few days to a week,” Evers says. A majority of eastern Canadian loon population stage in three of the Great Lakes: Erie, Ontario

LOONS PAIR UP WITH EACH OTHER, BUT THE PRIMARY LINK IS TO THEIR TERRITORY. THEY ARE BONDED TO IT FOR YEARS

and Michigan. All three of those lakes have had botulism outbreaks every fall, and sometimes in the spring, for the last decade. “The reason why it’s a problem now is because of introduced species into the Great Lake system,” says Evers. Before the coming of species like zebra mussels and quagga mussels, loons and other animals might have gotten a small amount of botulism in their system, but it wasn’t a big problem. Now, however, Evers says the invaders “concentrate the botulism that’s in the water column.”

Loons eat fish, not shellfish, but the freshwater goby — another invasive species, which the birds will happily eat — eats the mussels. In that way, botulism works its way up the food chain into the gullets of the loons, who ingest lots of gobies, and lots of botulism along with them.

“I’ve walked the beaches in New York in the fall, and every fall for the last 10 or 15 years, it just keeps happening. You have these fresh loons, there’s nothing else wrong with them, just lying dead on the beach,” he says. He estimates between 5,000 and 10,000 adult loons die of botulism each fall. Out of a total population of less than a million, that number is huge.

The common loon is currently classified as a species of least concern on the International Union for Conservation of Nature’s list of endangered species. It was last assessed by the IUCN in 2018. But common loons are

Wail

The wail may be the common loon’s most iconic vocalization. Wistful and eerie, the wail comprises two or three long, rising notes, with a dip in pitch toward the end. Loons send these enchanting calls across long distances to neighbouring lakes, sharing locations with their mates and other loons. If a loon is in a high-stress situation and perceives its chicks to be threatened, it may produce a wail intercut with more frantic-sounding calls, such as tremolos or yodels, to alert its mate of distress. (If you hear this up close, back away and give the loon some space.) Wails are frequently produced during night chorusing, often offered in answer to another loon’s tremolo.

Yodel

A common loon’s yodel, produced exclusively by males, serves as a territorial claim. Each is unique to the individual; yodels are known among ornithologists as a loon’s vocal fingerprint. Most yodels begin with three rising notes, followed by several dipping pitches, but even this basic pattern differs from loon to loon. When a male loon moves to a new lake, he will adjust his yodel to the new environment, making sure not to copy any neighbours’ or even predecessors’ yodels. These calls are often used to scare off an intruder or when a male needs to protect his territory from an encroaching bird. When a loon yodels, he may flatten his neck parallel to the water and arch his wings, making the yodel louder and making himself appear larger.

Hoot

A common loon’s hoot is a staccato, single-note and usually quiet call, most often made by a parent loon to locate their young or by mates to one another. This vocalization is the only call meant to be carried only across short distances, rather than across lakes. When a loon is particularly frantic about a family member’s whereabouts, the hoot may be accompanied by a “toot,” a higher-pitched version that conveys a sense of urgency. You’re less likely to hear the hoot in the spring, a time when most loons tend to stay close to their partners and do not yet have chicks.

ALWAYS LEAVE LOON’S NESTS ALONE. IF YOU APPROACH ONE, YOU WILL BE PUTTING THE CHICKS AT RISK

accumulated mercury (deposited by volcanoes and other natural processes and held within the permafrost) could be released into the water system over little more than a decade. In addition, the disturbance created by the thawing may release huge quantities of soil into freshwater systems, clouding the water, reducing the fish populations that loons rely on for food. More research is needed to understand how these climate changerelated issues will affect loons and make a plan to ensure the species’ survival, Evers says. And there are likely other issues yet to be discovered.

Still, says Kathy Jones of the Canadian Lakes Loon Survey, there’s plenty humans can do to help ensure loon survival — whether or not you spend time on a lake. Some things are common sense: try to reduce your carbon footprint so you contribute less to climate change, and responsibly dispose of things like packaging that have a way of ending up in waterways.

Protecting their habitat is another key, says Jones. “The wilder the shoreline, the better it is for the loons and the fish they feed on.” If you want to help, consider supporting (through volunteering or by donation) any other local community efforts across Canada focused on “rewilding” shorelines and ensuring infrastructure projects include efforts to protect loons and other wildlife. And finally: enjoy the loons on the lake but, as with all wildlife, stay away. If you’re in a boat, Jones says, give loon families a respectful distance and try not to split them up. If you’re on land, leave their nests alone. “Anytime humans interact with loons … you’re putting the chicks at risk,” she says.

The loons we enjoy today are a symbol of a successful environmental movement to clean up Canada’s lakes and stop creating acid rain. But they still need our help in the era of climate change and mass extinction. With care and attention, there’s hope that these beautiful Canadian icons and their haunting calls will be setting the lakeside mood for generations to come.1

To learn more about the loon survey, visit

birdscanada.org/loons.