"Wilderness can be appreciated only by contrast and solitude understood only when we have been without it."

- Sigurd F. Olson



Since 1978, the Sigurd Olson Environmental  Institute has recorded information on the common loon.  A loon’s location of breeding, number of adults and young, and time of residence on particular waterways are crucial for determining the loon’s status and survival rate in Wisconsin. In spring and summer, Siguard Olsen Environmental staff and volunteers throughout the state help achieve project goals by monitoring loon populations on lakes and reporting valuable nesting information. It’s not an easy life for the common loon. Nesting sites are gradually being decreased because of shoreline development. Harassment (both intentional and unintentional ) by lake users has regrettably added to mortality. Both air and land pollution have decreased the loon’s chance for survival.


Support Wisconsin Loon Watch.  If you live or vacation in northern Wisconsin, you can volunteer to monitor a lake.  If you do not, you can still help tremendously by making a tax deductible contribution so that Wisconsin Loon Watch can maintain our research and education efforts for the loon.  It is time to take action.  We need to develop protective attitudes so that this symbol of the north country will continue to have aplace to call home.
Your help is needed today.  Please contact: Wisconsin Loon Watch, Sigurd Olson Environmental Institute. Northland College Ashland, Wisconsin 54806 (715) 682-1220.

Things To Remember To Help Protect Loons

View loons from a respectful of at least 200 feet

Do not approach nests, individual adults, or loon chicks.  Do not camp, picnic, or run dogs on islands potentially used as nest sites by loons (esp. from spring ice-out until July 4).  You invite predators to eat the loon eggs and chicks if you flush a loon off its nest or separate the chicks from the adults. Intentional harassment of loons is illegal under the Migratory Bird Treaty Act and carries a fine of $5000 and a 6-month jail sentence.

Respect slow-no wake zones and rules

Because loons nest right at the water's edge, wake from boats and personal watercraft can wash eggs out of the loon's nest.

Don't fish next to a loon

Loons can mistake lures and jigs for their live prey items.  Every year loons die from swallowing lures and entanglement in fishing line.

Use non-lead fishing tackle

Loons, eagles, swans, and other waterbirds die from ingesting lead fishing tackle.  They ingest the tackle when they eat fish that have tackle left inside by anglers or when they pick up pebbles (or in this case, sinkers or jig heads that look like pebbles) to aid with digestion.  Small sinkers and jigs seem to be the biggest problem, and only one lead sinker will kill a loon from lead poisoning.  Of 12 dead loons turned in by the public to DNR for a new loon health monitoring program in 2006, six died from lead poisoning from lead fishing tackle.  Most of the affected birds came from north-central Wisconsin (3 from Oneida County, 1 from Vilas County, 1 from Iron County, and 1 from Door County; Note: The loon from Door County was a known summer resident of Vilas County—must have been found dead on migration).

Check your boat for aquatic invasive species.

Before you launch your boat or after you trailer it, please check the boat propeller, trailer, and other places for invasive plants such as Eurasian watermilfoil and curly-leaf pondweed.  These plants can negatively impact the fish population, lake ecology, recreational use, and ultimately the loon use on a lake.

Leave native vegetation and woody debris on the shore and in the water.

Removal of woody debris from the water has been documented to cause population crashes in perch populations on a lake.  Perch are the primary food for loons so a crash in the perch population may result in less food for chicks and loons abandoning their use of a lake.  Fish populations rely on good aquatic plant and woody debris structure for protection and nursery areas.  Leaving a buffer zone of native plants along the lakeshore will provide nesting cover for loons and other birds.

Use four-stroke motors or no motors at all

Four-stroke motors contribute less pollution to the water and air.  They are more efficient and use less oil-based products compared to older two-stroke motors.  Hundreds of loons (for some states this is equal to their entire population) can die in one oil spill.  Reducing our dependence on foreign oil reduces the chances of oceanic oil spills that can have major ecological impacts as well as catastrophic wintering loon impacts.

Spread the word

about these issues to your family, guests, neighbors, and other visitors to the lake.


What do loons look like?

Loons are powerful, streamlined birds with red eyes, greenish black head, long tapered beak and black and white checkerboard plumage.

How large are loons?

The common loon (Gavia immer) stands approximately 25 inches tall, weighs between 8 and 11 pounds and has a wingspread of 5 feet.

Are there different species of loons?

There are 5 species in the northern hemisphere.  You are missing the Pacific Loon—the North American relative to the Arctic Loon (the Arctic Loon is found in the old-world—arctic areas of northern Europe and Asia.)  So your statement about the other 3 species that breed in Alaska and Canada is incorrect.  It should be 4 species though technically Arctic Loons are very rare breeders in Alaska.

Are loons good swimmers?

Loons are supreme rulers of their aquatic domain. With legs located well back on their sleek bodies, loons are superb swimmers easily capable of catching fish for food.

Are loons good divers?

Unlike other marine birds, loons have dense bones which permit them to dive to depths of 200 feet and remain submerged for 5 to 10 minutes.

Do loons ever come to shore?

Loons do come ashore but only to nest. With legs positioned behind their balance point, loons have great difficulty walking or even standing.  It is not unusual for loons to support some of their weight on land with their chests.

Why are loons eyes red?

The red is caused by a pigment in the retina that filters light when loons dive beneath the waters surface and allows for sight.

How can one determine the difference between the male and female loon?

You can determine sex in some cases.  For example, only the male will yodel.  Also the male is usually larger than the female which is sometimes apparent if you see the male and female of a pair side-by-side.  Otherwise you are right about needing to look at internal organs or by doing a blood test.


Where do loons go during the winter?

We now know that Wisconsin loons winter off the Atlantic and Gulf of Mexico Coasts.  This is known from loons tracked by satellite transmitters and observation of banded loons.

Do loons migrate in flocks?

Yes, in late autumn, generally well before the great freeze, loons congregate on large lakes and fly south together.

Do immature loons return to the North Country after their first migration south?

Young and immature loons are believed to spend two or three years in coastal waters beforemaking their first trip back to the North Country.

How many loons inhabit a lake?

Loons are territorial birds and generally only one pair is found on each lake, except for very large bodies of water where several pairs inhabit a lake.

What size body of water can support a loon population?

Research conducted by Wisconsin Project Loon Watch indicates that loons inhabit bodies of water as small as nine acres.

Why are loons sometimes observed in large gatherings during the summer?

This is a social preparation for migration.

What do loons eat?

Loons feed primarily on fish, frogs, crayfish, mussels, leeches and aquatic insects. By the end of summer the young fledglings are capable of feeding themselves.

Why are loons observed running across the water?

Because of their large size and weight, loons require about 1/4 mile of lake surface to become airborne and thus appear to run across the water before taking off.

Are loons strong fliers?

Once airborne, loons are powerful fliers. Pilots have clocked them flying at speeds up to 80 mph.

How do mates locate each other?

It is assumed that loons return to the same lake every year.  Males claim the same territory and await the female’s return.

Why do loons make so many weird calls?

Loon calls have been identified into four classifications: Wail, Tremolo, yodel and hoot.

  • The wail is perhaps the call most frequently heard.  A loon will wail when it becomes separated from the chick or if its mate fails to return. The tremolo is an aggressive response given when disturbed by a boater or predator. The yodel is also an expression of aggression and is given by the male during a confrontation.
  • The hoot symbolizes a call of curiosity and/or happiness.

The sounds are apparently a learned communication between the birds. To hear the richness of their harmonics is clearly a unique experience.

Why do loons sometimes stand up on the water with their wings extended?

Loons rise up on the water to preen themselves, to stretch their wings or to dry their wings after a drive.

When approached, why do loons sometimes stand up on the water with their wings tacked to their sides, like penguins?

The "penguin dance" is a sign of extreme agitation.  This behavior symbolizes that the loon’s territory has been violated.  The penguin dance is generally combined with frantic calls and is one of the last defense actions available to loons.  Anyone observing such a response should retreat immediately.

Why do chicks ride on their parents backs?

With their young on their backs, the adult loon can provide better protection from predators both above and beneath the waters surface.  This is an opportunity for the young to conserve energy and body heat



Do Loons Mate for Life?

Not really. Banding records show that loons often return to the same lake each year.  However, mates probably don't winter or migrate together and return to the same lake independently.  Loons do occasionally switch mates and seem to be more attached to their lake than to each other.

Do loons have a courtship ritual?

Yes, Courtship consists mainly of head dipping and shallow dives. In spring, loons are frequently observed chasing each other across the surface of a lake; this is primarily territorial behavior not courtship ritual.

What does a loon nest look like?

The nest consists of reeds, sticks, grasses and muddy vegetation from the bottom of the lakes.  This material is loosely formed in the shape of a mound, roughly 1.5 feet in diameter, with a slight hollow in the middle.  Both the male and female participate in nest building which is completed by mid-May.

Where do loons construct their nests?

Because of their difficulty moving about the land, loons build their nests within a few inches of water. When a nesting loon is disturbed, it slips off the nest and submerges to keep the location of its nest unknown.

How many eggs does the female lay?

Soon after construction of the nest, the female lays two eggs.

What size and color are loon eggs?

Loon eggs are roughly 3 1/2 by 2 1/4 in size with a thick shell and are olive green color speckled with brown spots.

How long do loons live?

The common loon may live twenty years or more.

How many loons are there in Wisconsin?

The Wisconsin loon population was estimated at 3400 adults and 800 chicks in 2005.  This is from LoonWatch's Wisconsin Loon Population Survey conducted on one day every five years thus the next survey will be in 2010.