Over the last seventy years, northern Wisconsin has experienced increasing development. Housing density maps from 1940, 1990, and 2010 clearly show cumulative density throughout the decades, particularly in the lakes regions. What does this mean for loons? Loss of habitat, declining water quality, and increased recreational use of lakes influences loon presence and survival.
For so many people who visit or live in the north woods, loons are an integral part of the lake experience. So why do some lakes have loons and not others? Loons need healthy aquatic ecosystems with good water quality, abundant prey, irregular shaped shorelines or islands with native vegetation, and nursery habitat with little to no human disturbance.
Therefore loons are considered to be an indicator species, meaning that the presence of a loon may indicate that a lake they live on or frequently visit is healthy. Here are some things you can do to help protect the habitat and loons on your lake.
Practice Good Loon Etiquette
- Watch loons from at least 200 feet away. Get a powerful lens for your camera, use binoculars or a spotting scope, and never explore a loon nest site. Close encounters can be deadly for swimming and nesting loons.
- Avoid exploring or camping on islands before July 15 of each year. Loons prefer islands for nesting. Disturbance can cause a loon to abandon its nest.
- Dispose of household garbage at a collection site. Garbage draws raccoons, foxes, gulls, and eagles, which prey on loon eggs. Trash can also ensnare wildlife, including loons.
- Be an ethical angler. Never fish or cast near loon nests or swimming loons, properly dispose of extra bait and trash, and pick up monofilament line.
- Keep dogs and cats away from loons and nests. Pets disturb nesting loons and can destroy loon eggs.
- Be a responsible boater. Never chase loons or run motorboats or personal watercraft over areas where loons have been seen. Loons and loon chicks have died from being hit by boats and propellers. Boat wakes and waves may also wash eggs off of nests.
- Practice and teach wildlife stewardship…always!
Protect and Restore Loon Habitat
- Protect native vegetation on all shores. Loons nest on natural shorelines and use natural materials to build their nests. Native vegetation also protects water quality by slowing and absorbing runoff materials from entering the lake.
- Use only phosphorus-free fertilizers on shorelands, and only if needed. Fertilizer that runs off into lakes increases aquatic plant growth, making it difficult for loons to swim and find food.
- Protect loons from your pets. Keep dogs and cats away from loons and nests. Pets disturb nesting loons and can destroy loon eggs. And please clean up your pet’s waste—pet waste can also contribute unwanted nutrients and bacteria to the water.
- Pollutants from fertilizers, pesticides, streets, and rooftops are contaminating your lakes and rivers. If heavy rains collect in pools and puddles in your yard, the easiest way to help water infiltrate into the ground rather than run off into storm sewers is by creating a rain garden and using rain barrels to collect rain water from your roof gutters.
- Loons need good water quality, healthy lake habitats and ecosystems to survive and thrive. Local government agencies do not have the capacity or resources to monitor the water quality on all Wisconsin lakes; therefore, volunteer monitoring is a vital component to determining the water quality of our state’s lakes and rivers. Learn about Wisconsin’s volunteer water quality monitoring.
- Make sure your septic system is functioning properly. When septic systems don’t work properly, they pose serious risks to human, animal, and environmental health by releasing contaminants, including harmful bacteria and chemical pollutants, into the groundwater and into surface water—lakes, rivers, marshes, and streams.
Reduce Your Energy Consumption
- Sources of mercury in the United States include: 40% from mid-western power plants, 40% from New England power plants and incinerators, and 20% from global sources.
- Most, if not all, mercury entering the Earth’s surface waters comes from the atmosphere. Particles generated by power plants are emitted into the atmosphere, and raindrops form around these particles.
- Mercury, like many toxins, bioaccumulates. This means that as mercury moves up the food chain, it becomes more concentrated.
- Loons have no metabolic means for eliminating the toxin so it accumulates in their bodies. Adult loons can pass mercury on to the egg. This can cause lack of motor coordination in chicks and other effects on the nervous system. These chicks will most likely not survive into adulthood.
- The Deepwater Horizon oil spill has had and will continue to have an impact on loons and many other water birds. In three months, it released 4.9 million barrels, about 205 million gallons, of crude oil into the Gulf of Mexico.
- Posing the largest risks to wildlife in the area of the spill are petroleum toxicity, oxygen depletion, and the presence of oil dispersants.
- Loons eat almost exclusively fish, which will hide under oil slicks as they would under floating vegetation or sea foam. The birds will be covered in oil when they surface and will ingest the oil when preening or while eating contaminated fish.
- Internal exposure to oil can lead to ulcers, pneumonia, liver damage, or other life-threatening conditions.
- Oil causes birds’ feathers to mat and separate This causes the bird to lose buoyancy and the ability to regulate body temperature. It will also cause the bird to lose its ability to keep its down, insulating feathers dry, resulting in hypothermia. Contact with oil on the skin or face can cause lesions.