There never was a more Minnesotan bird. The Loon’s call is part of the North Woods soundtrack, or the wilderness at large. Folks are most familiar with the geometrically patterned summer plumage in black and white, with red eyes, though in winter they’re gray above and white below. They’re often found in pairs swimming and diving together on lake waters, agile divers that catch small fish in underwater chases. They come ashore only to nest.
Most Common Loons breed in Canada, but some breed in Minnesota and Northern areas of the Great Lakes. Then they migrate through the lower 48 states to Pacific and Atlantic shores. The tremolo call is an aggressive response to boaters or predators, and signals distress or presence at the lake. The yodel is a territorial call to other loons, and each male has his own signature yodel. The hoot is a call of curiosity, happiness, or a little love note to chicks or mates. Hear these calls here.
They are excellent indicators of water quality as they require crystal-clear lakes (which makes it easier for them to see prey underwater) with abundant populations of small fish. Their diet consists mostly of fish, particularly perch and sunfish, on their northern lakes. If fish are scarce or water is too murky for fishing, they will catch crustaceans, snails, leeches and even aquatic insect larvae. Underwater, they’re like torpedos, able to do flip-turns on a dime by extending one foot laterally as a pivot brake and kicking with the opposite foot to turn 180 degrees in a fraction of a second.
Loons also perform a territorial display of lifting their body upright and flapping their wings vigorously, and males signal vocally with a yodeling call. Loons are monogamous, and pair bonds typically last about 5 years. If one year one of the mates doesn’t return, the other will quickly pair up with another mate. Courtship consists of swimming in circles and synchronous dives.
The male selects the nest site. Loons nest in quiet, protected, hidden spots of lakeshore,. Nests are made with vegetation from the lake edge. Loons can’t walk well on land, so nests are built close to a bank, often with a steep dropoff that allows the bird to approach the nest from underwater. They also use artificial nesting platforms, which people have offered as alternative habitat on lakes with extensive shoreline development. Many times a nesting pair of loons will reuse the same site the following year, refurbishing their old nest instead of building a new one. A clutch is 1 to 2 eggs. Loon chicks are often seen riding on their parent’s backs.
Common Loons require clear, unpolluted lakes and can be harmed by pollution and disturbances. Regional declines have occurred at the southern edge of their range. In the Midwest, loons have disappeared from breeding sites in Illinois, Indiana, Iowa, and Ohio, and are only found in northern areas of Minnesota, Wisconsin, and Michigan. Their range has retracted in New England as well, though loon populations have rebounded there thanks to restoration efforts. Lead fishing sinkers, which loons ingest when they scoop up pebbles off the lake bottom to store in their gizzards, have been a significant cause of loon deaths from lead poisoning. Mercury, from the burning of coal, can build up in lakes through rainfall, and this has led to poor reproductive success for Common Loons in Canada, New England, and Wisconsin. Common Loons are often caught inadvertently by commercial fishing nets, both on the Great Lakes and in the ocean. Acid rain can acidify lakes, reducing fish populations that loons depend on. Human activity, particularly motorboats, can disturb loons on breeding lakes. Ocean oil spills can cause die-offs on loon-wintering waters.
Original mixed media on raw stretched canvas with maple float frame. Alternative hardwood frames available upon request.
Sources: All About Birds and Audubon Society.