WCS North America

Common Loon

The Common loon is an iconic symbol of the expansive open waters and wilderness of the Northern Forest.  The worldwide population of Common loon is estimated at 500,000-700,000 individuals, with a breeding range across Canada and the northern U.S. states. A declining trend along the southern range limit in the mid-twentieth century was reversed in the 1970's and 80's, and loon populations in these regions now appear relatively stable.Northern waterways are not the pristine nursery that they appear to be, however, and loons face threats such as mercury contamination and lead pollution, interfering with their health and their reproductive success.Mercury and acid emissions from coal-fired power plants detrimentally affect both human and ecological health.Loons are also adversely affected by degradation of habitat and human disturbance. To understand the impacts of these threats and provide science-based information and conservation solutions for this species and these aquatic habitats, WCS has been studying loons in the fresh water lakes of the Adirondack Park since 2001.

A Species of Special Concern in New York, the Common loon is a powerful tool for understanding threats to aquatic ecosystems and the relative impacts of toxins such as mercury and other heavy metals, which have disproportionately large impacts on these top predators. Mercury, a byproduct of coal-burning power plants and trash incineration, is transported to the Adirondack landscape through prevailing winds and deposited in lakes and ponds in the form of rain or snow. Along with acid rain, mercury enters lakes, where it is converted into a more toxic form called methylmercury, which accumulates in the aquatic food chain. Top predators like humans and loons are most affected by this concentration of toxins in the food chain. To minimize the impacts on human health, state health departments issue warnings about the amount and type of fish people should consume.  For loons subsisting entirely on a diet of fish and other aquatic animals, the neurotoxins concentrating up the food chain can impact behavior and reproduction, leading to changes in population size over time.

Few other iconic species in the northeastern U.S. provide such extensive opportunities for viewing and observation of natural behaviors, and few other species have garnered such intense levels of public interest and engagement in monitoring and conservation activities. WCS is engaged in loon conservation in order to connect people to nature, address key threats to our ecosystems, and ensure the protection of this magnificent species and its aquatic habitat.


Adirondack Loon Conservation

Since 2001, WCS has been engaged in research and education efforts to ensure the conservation of the Common loon in the Adirondacks. Read More >>


Adirondack Communities and Conservation Program
Wildlife Conservation Society 132 Bloomingdale Avenue, Suite 2, Saranac Lake, NY, 12983 USA
(518) 891-8872