Canada’s second-most iconic bird is in danger: What you can do

A new study has found evidence that common loon populations in Canada may be facing a substantial decline. Researchers analyzed breeding and population data gathered by various monitoring projects over the past few decades, which spanned nine provinces, five states, and 3,421 total lakes.

What they found was an overall decreasing trend in the number of fledglings successfully reared by mated loons, referred to in the study as “productivity.”

While decreased productivity doesn’t always correlate with population decline, the researchers say it does sound an alarm that we may be seeing the early signs of a major decline in the near future.

Common loon breeding range in North America, along with points showing each lake that monitored loons used in the study. (Fuirst et al./FACETS (CC BY 4.0))

Prairies and Atlantic Canada show evidence of steepest declines

Decreased productivity was observed across all of Canada’s provinces and was categorized between provinces based on the strength of evidence.

Strong evidence of a steep decline in loon productivity was found in Atlantic Canada and the Prairies, where data showed 74 per cent and 65 per cent declines, respectively, between 1992 and 2023.

Moderate evidence of decline was found across Ontario, where a 45 per cent decline was recorded between 1981 and 2023. While that number seems comparable to Atlantic Canada or the Prairies, it’s important to note the longer timeframe. In actuality, the data shows an approximate 1.08 per cent decline per year in Ontario, compared to the 2.39 and 2.09 per cent yearly decline in Atlantic Canada and the Prairies.

Meanwhile, British Columbia had weak evidence of productivity decline and Quebec showed near-stable levels, although leaning on the negative side.

Map showing the overall loon productivity trend in per cent per year across the regions studied. (Fuirst et al./FACETS (CC BY 4.0))

Climate change, land-use among possible causes

There is no single cause of this reported decline in loon productivity and population growth, however, researchers are confident that climate change and human activity play a significant role.

One hypothesis the study authors proposed is that increased storm frequency and severity around loon breeding habitats may cause damage and flooding to nests. This may result in the breeding loons abandoning their nests, or in hatched chicks being killed by the extreme conditions.

Increased rainfall may also result in lower water clarity in lakes, preventing loons from successfully foraging for food for their young. This hypothesis can be backed up by a study from 2024 that was published in the journal Ecology.

Loons often carry their offspring on their backs to protect the babies from predators and to help conserve energy. (Credit: Kevin Clarke)

Another hypothesis that was proposed suggests human shoreline development has contributed to decreased productivity in loons through destruction, contamination, or general disturbances from human activities.

Other possible causes listed in the study include:

• Increased chick predation by raccoons and eagles

• Increased black fly populations

• Increased lake acidity

• Lead poisoning from fishing lures

• Methylmercury contamination from increased pollution

What you can do to help your local loons

If you want to play an active role in protecting Canada’s second-most iconic bird, you can volunteer in the Canadian Lakes Loon Survey. This annual event is dedicated to monitoring loon populations and breeding across Canada, as well as sharing observations and acting as a steward for our lake-dwelling avian friends.

Repeated flood events or increased blackfly populations may cause a loon pair to abandon their nest. (Credit: Kevin Clarke)

However, if you’d rather play a more passive role in supporting loon populations, there are plenty of other things you can do, such as:

• Slow down when boating near wetlands or shorelines

• Keep a respectful distance away from loons on the lake

• Use lead-free fishing tackle

• Opt for a naturalized shoreline

• Clean up litter along the shoreline

More tips and resources about how you can help support your local loons can be found at Birds Canada.

Thumbnail image courtesy of Seth Macey.

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