Fewer loons on your lake? It may be due to climate change

Common loons are currently listed as a species of least concern, but decades of slow population decline have researchers worried about the iconic bird’s future.

It lends its name and likeness to our $1 coin, and its calls are synonymous with Canadian summers. But within our lifetime, experts say the common loon could go silent in some regions. 

The iconic bird is currently listed as a species of least concern, but new data from the Breeding Birds Survey, a joint Canada-U.S. monitoring program, shows Canada’s adult loon population dropped nearly 14 per cent between 2005 and 2022, based on reports from volunteer citizen scientists. 

Doug Tozer, director of Birds Canada's Waterbirds and Wetlands program, says their absence on lakes is now being reported across the country.

“Even within a decade or less, it'll get to the point where … ironic as it sounds, the common loon could be designated with some sort of threatened status in Canada,” said Tozer. 

“Which is just unbelievably mind-boggling to me that this is possible this soon, the common loon becoming uncommon.”

Flying south

South of the border, the data paints a more dire picture.

Walter Piper, a biology professor at Chapman University in California, has been tracking loon populations in Wisconsin since 1993 — adding Minnesota in 2021. 

Now monitoring more than 100 loon breeding territories across the two states, Piper found overall adult populations plummeted 22 per cent over 27 years in northern Wisconsin. When looking at “floaters” — young adults who are not yet breeding — it gets worse still.

“About 50 per cent of all the birds that we banded as chicks, we would see them as adults,” said Piper of the mid-2000s. “Now it's down to about 10 per cent of all of the birds that we banded as chicks. So it's absolutely a staggering and alarming decline.”

The breeding range of common loons is expected to shift hundreds of kilometres northwards in the coming decades due to climate change. With the U.S. Midwest at the southern end of that range, Piper projects the overall population there will drop 52 per cent by 2031. “And by 2080, the population will be entirely or virtually entirely gone,” he said. 

What’s taking the ‘common’ out of common loons?

While the specific cause of the declines isn’t certain, a number of factors are likely at play, with climate change taking centre stage.

As of 2022, the species was already producing up to 30 per cent fewer chicks than the early 2000s. “The chick reproduction rate is lower than would be optimal to maintain long-term populations,” said Doug Welykholowa, who has monitored loons at Duck Mountain Provincial Park on the border of Manitoba and Saskatchewan for the last 16 years.

In 2024, Piper’s research found climate change was making water cloudier through more frequent extreme rainfall events. Since loons hunt fish by sight, Piper says it’s meant loon chicks struggle to get enough food, and are an average of 11 per cent lighter than in the early 2000s. 

Due to what he calls the “silver spoon effect,” Piper says the first five weeks of nourishment essentially determine whether chicks survive into adulthood, return to the breeding grounds, and make chicks of their own.

“The die is sort of cast early on for loons,” said Piper. “You know, humans that were born with a silver spoon do better, have a big advantage throughout life. Well, in loons it's a much more serious matter because it's a life-and-death situation.”

Tozer says warmer water means more mercury is winding up in aquatic environments — and since loons feed at the top of the food web he’s also seeing more mercury poisoning in loons. He notes those factors likely also impact loons’ food supply in wintering grounds in the southern U.S.

Since loons nest right by the water’s edge, Tozer says extreme rainfall events, which are becoming increasingly common, can flood nests and create ideal spawning conditions for black flies, causing the birds to abandon their nests. 

“They just give up and wait till next year — no chicks at all,” Tozer said.

What’s a bird lover to do? 

While the figures spell doom and gloom, loons are far from a lost cause.

Piper says if he could solve one problem affecting loons — short of climate change — he would get rid of lead fishing gear. He says swallowing lead tackle is overwhelmingly fatal for loons, as they stop caring for themselves.

Tozer says people can also dispose of fishing line properly, keep shorelines natural and avoid disturbing nests or separating chicks from parents while boating.

“People love loons, and if you tell people ‘this is hurting loons and that's hurting loons,’ perhaps we can encourage them to make some adjustments,” said Piper. “I have some hope that we can turn things around.”

— Martin Halek
 

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Reader Feedback

Last week, we had a story by Jennifer Wilson about public safety power shutoffs, a policy that some electricity companies use to prevent sparking wildfires. We heard back from many readers, including Brenda Andrews, who lives near Kamsack, Sask.: “In fact it was done one October in Saskatchewan several years ago. It was extremely dry, harvest left dry stubble, extremely high winds created a dangerous fire circumstance so power in areas of above-ground lines was shut off across southern Saskatchewan….  Our power was off [for] about 18 hours.”

We asked SaskPower, the main electricity provider in Saskatchewan, whether it had a PSPS policy, and if so, whether it had ever initiated a PSPS outage. Joel Cherry, with SaskPower’s media and communications team, said in a statement that it hasn’t yet needed to “undertake a planned power outage of this nature.” He added: “from the customer’s perspective, a power outage may seem to be in advance of a potential risk but actually the result of damage to equipment some distance away.”

Gareth Williams sent this email in response to the same story: “[I] noted the section about utilities chipping in to get people backup generators/batteries. I believe resiliency is something that isn't talked about enough. Thanks for addressing this. I did have a few additional points you might consider sharing with your readers: Hydro One in Ontario did have a program to offer battery backup for free a couple of years ago but it is no longer being offered. Would be curious if they plan to resume it at some point, maybe you could reach out to someone there? Ontario is also offering a rebate for battery backup and/or solar under its Home Renovation Savings program. The catch is that the program does not allow for Net Metering to sell excess power back to the grid. The ongoing Canada Greener Homes Loan Program (not to be confused with the no longer available Grant program) also provides interest free loans for solar and battery backup.”

Adding to Gareth’s list, B.C. Hydro, the province’s main electricity provider, offers rebates for battery backups to homeowners and businesses. FortisBC, which serves parts of the province and was featured in the story, does not. 

This would also be a good place to note that we should have credited that story to Jennifer Wilson. 
 

Write us at whatonearth@cbc.ca. (And feel free to send photos too!) 

The Big Picture: A fox's smoldering gaze

Maxime Légaré-Vézina was just named Canadian Geographic magazine's Wildlife Photographer of the Year, one of the highest awards for photography in Canada. This striking photo of a cross fox — a variant of the red fox — was one of his submissions to the competition and taken on Quebec's Anticosti Island. "I was basically walking down the beach. It was very, very early in the morning,” he said. "She was actually walking along the coastline trying to find something to eat." A former bank employee, Légaré-Vézina switched careers three years ago to pursue his love for wildlife and photography. He will soon depart for British Columbia for a two-year photography project with the magazine documenting a conservation-related issue.

— Inayat Singh

A Nova Scotia project is raising an insect army to protect hemlocks

Kirk Hillier, a biology professor at Acadia, demonstrates the containers that will eventually house the insect predators meant to control hemlock woolly adelgid.

High in the tops of some of Nova Scotia's largest trees, a black speck no bigger than a sugar crystal is wreaking havoc. 

The hemlock woolly adelgid, first seen in the province in 2017, is an invasive insect moving rapidly through Nova Scotia's hemlock forests, leaving ghostly trees in its wake. By sucking sap from the base of hemlock needles, the adelgid can kill a tree in less than a decade. The insects leave behind a white substance that looks like wool, giving them their name.

On the campus of Acadia University, scientists are investigating what it will take to find a solution. 

A research project led by Acadia is investigating the effects of insecticidal treatment that are being used to control the hemlock woolly adelgid. They're also establishing a biological control facility that will be used to keep adelgid populations in check. 

"For me, the urgency is very obvious," said Kirk Hillier, a biology professor at the Wolfville, N.S., university and lead researcher on the project. "I've seen the dead trees — I've seen what we call the grey ghosts of dead hemlocks. So it's a significant threat."

Researchers say measures needed to counter a fast-moving danger

The project has two elements. First, it is working to assess the effects of adelgid infestation on biodiversity, as well as the impact of insecticides.

Hemlocks are now treated with two types of insecticide, either by injecting it into the tree or spraying it on the bark.

"This is an unfortunate but necessary element to keeping trees alive, because without insecticide protection these trees will perish," said Hillier. 
 

An outbreak of hemlock woolly adelgid, an invasive, aphid-like insect species that kills hemlock trees by sucking sap from the base of their needles. 

In other contexts, such as agriculture, scientists have found potential impacts on pollinators from these types of insecticides. But in Nova Scotia, these potential impacts have to be weighed against the effects of losing the hemlocks entirely. 

To assess this, the research will be trapping insects and birds to determine whether there are changes to biodiversity from trees dying in infested areas, as well as the relative risks of insecticides to birds, insects and salamanders. 

To help guide treatment to where it's needed most, the project is testing funnel-shaped traps to detect the adelgid at very low levels, using molecular tools. 

"Basically what we're looking for is not necessarily the insect, but DNA that comes from the insect," said Martin Williams, genomics research scientist with the Canadian Forest Service, which is partnering on the project. 

"Once you get to a certain point in the infestation, there really is nothing you can do," said Williams. "If you can do early detection, especially in an urban centre, for example, then you can manage … that location, to slow it down."

Long-term biocontrol necessary

In the long term, traps will also help detect hemlock predators — an important step, since scientists say saving hemlocks depends on the hemlock woolly adelgid's natural enemies, including a small, black beetle named Laricobius nigrinus. Since 2023, the Canadian Forest Service has painstakingly collected roughly 12,000 of the beetles in British Columbia and released them in Nova Scotia.

Acadia researchers aim to expand those efforts, using a greenhouse on campus as a rearing and testing facility.

The biocontrol facility will allow researchers to collect a secondary predator that's present in B.C. called a silver fly.

"[The silver fly] really works in concert with the beetles," said Hillier.

This requires using the greenhouse to bring in foliage from B.C. that's infested with the western strain of hemlock woolly adelgid; that foliage also contains silver flies, which will be raised in the lab.

Eventually, Hillier hopes the facility could get to the point of releasing 50,000 to 60,000 predators a year in the province. 

Ultimately, Hillier said, the biocontrol facility will be able to provide predators not just for Nova Scotia, but for other parts of the country, as the hemlock woolly adelgid spreads in other provinces. 

'It's the morally right thing to do'

Donna Crossland, a forest ecologist who's been involved in protection measures for hemlock since first learning about the threat when working for Parks Canada in 2017, said it's important that the project is considering the short- and long-term measures to control hemlock woolly adelgid.

Like many ecologists, she said she was initially fiercely resistant to the idea of using insecticides to protect hemlocks. Over time, she came to see it as a necessary tool, until biocontrol can be implemented. 

"It's a last resort," she said. "We will not receive any benefit from a biocontrol program in hemlock if we don't use some chemical control in the interim."

Laricobius nigrinus beetles are a natural predator of hemlock woolly adelgid but they don’t exist in the province. These two began eating the invasive insect as soon as they were released at Kejimkujik National Park in southwestern Nova Scotia. 

Crossland commends scientists for getting a biocontrol facility started, but said she's concerned the province has not yet made a funding commitment to fund a biocontrol program for the long term.

"We need that desperately," she said.

In response to a question about long-term funding for biocontrol, a joint response from the Department of Natural Resources and the Department of Environment and Climate Change said that the province has committed $3 million to treat high-value hemlock stands, and that Natural Resources is working with Acadia to build the biocontrol facility.

Crossland said government leadership is needed to keep that program running and ensure it doesn't fall through the cracks in the future. 

"It's the morally right thing to do to conserve something that's been here in Nova Scotia for thousands of years, and we're going to lose it at the near blink of an eye."

Hillier said the pace of that change is why he's continuing to push for public awareness, and for operational funding for a biocontrol program, because the longer it takes to get that program established, the fewer trees will be left to save — a reality that has direct resonance for many Nova Scotians.

"I've worked on a lot of different projects in my career, and this one is actually something that is unique for me because I can … walk behind my house, and there are hemlocks everywhere, and I know that many of those trees are doomed. 

“So it's something that is not esoteric at all — it's something that is very fundamental."

— Moira Donovan