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What can loons tell us about lake health?
Common loons are an iconic sight in local lakes and ponds during the summer breeding season, and their wailing call is unforgettable. These diving birds are also excellent indicators of environmental health in aquatic ecosystems because they are sensitive to changes in water quality, contaminants like mercury, human disturbance, and habitat degradation. As long-lived (20 to 30 years!), fish-eating birds at the top of the food chain, they can accumulate pollutants in their bodies, and their reproductive success reflects the overall condition of a lake.
Coastal Rivers volunteers are actively engaged in loon conservation efforts including installing and monitoring loon nesting platforms and taking part in an annual loon count with support from Maine Audubon.
Loon nest rafts
Loon nests are very vulnerable to boat wakes as well as predation by raccoons and other scavengers whose populations are unnaturally high because of the availability of food from human sources. Shoreline development and human activity along the shoreline can also impact potential nesting locations.
In areas where natural nests are failing, a nest raft may a good option. A floating raft is less likely to be flooded, as it can rise and fall with any waves. Located off shore, it is out of reach of most predators and land-based human disturbance. Adding a cover to the raft offers protection from raptors and other avian predators.
Once deployed, nest rafts are monitored occasionally throughout the nesting season from a safe distance.
Annual Loon Count
Organized by Maine Audubon, the annual loon count takes place on the third Saturday of July. The data, collected by more than 1,600 volunteers in lakes and ponds across the state, provides insight into how the loons are doing.
Coastal Rivers traditionally hosts a breakfast for local volunteers following the count.
Maine Audubon
Learn more about the Annual Loon Count and see results
Interactive data
Filter loon count data by lake or pond, year, or county (Lakes of Maine website)
What you can do to help protect loons
- Loons typically build their nests just inches above the water’s surface, so they are easily flooded. Keep your boat at least 125 feet from loons and make sure to observe no-wake zones.
- A significant number of loons die from lead poisoning when they swallow abandoned lead fishing tackle. If you have any lead tackle, exchange it for a lead-free option (this can be done for free at Coastal Rivers).
- When the water is cloudy, loons have trouble seeing fish when hunting. Keep lakes clean and clear by not using fertilizer on shorefront properties. A generous buffer of native vegetation along the shore will act as a natural filter to keep pollutants out of the water.
- Observe loons from a distance, using binoculars. Learn to recognize their distress calls and behaviors as a sign to keep away.
Resources
Living in Loon Territory
A Maine Audubon publication for residents, visitors, anglers, and boaters
How Close is Too Close?
An overview of loon stress behaviors by Maine Audubon
