Minnesota's state bird, the common loon, is considered a symbol of wilderness. Its unique call, heard day or night, signals the return of summer to the north woods and one of the region's most iconic birds.

More at home in the water than on land, loons swim underwater in search of prey. At 8 to 12 pounds, the loon is larger than a duck but smaller than a goose. The bird can be easily identified with its thick neck, long black bill, red eyes, and spotty black and white summer coat. Its legs are set far back on its body, making walking on land an awkward experience.

The common loon has four calls: the tremolo, wail, hoot and yodel. The tremolo is an aggressive call that sounds like laughter. The yodel is used by males guarding their territory. The wail is a long, drawn-out call, while the hoot is a shorter call used to communicate between parents and young.

According to the Minnesota Department of Natural Resources, a loon's diet consists mainly of fish including: panfish, perch, ciscoes, suckers, trout, bullheads, smelt and minnows. They also may eat frogs, leeches, crayfish, mollusks, salamanders, amphipods and insects.

On the other end of the food chain, adult loons are rarely eaten by other animals except bald eagles. Young loons, however, are prey to skunks, raccoons, foxes, snapping turtles, northern pike and muskies.

Human disturbance and pollutants such as lead and mercury also present a threat to the loon population.

Young loons leave the nest within one or two days after hatching and can dive and swim underwater when they are 2 or 3 days old. Young are tended and fed by both parents and when small, sometimes riding on parents' backs. They are capable of flight at about 10 to 11 weeks after hatching.

Minnesota has more common loons than any other state except Alaska. Loons make their summer home across the northern part of many Midwest lakes. In the colder months, loons travel to the Atlantic coast as far north as North Carolina to as far south as the Gulf of Mexico.

Facts about loons

• The bones of most birds are hollow and light, but loons have solid bones.

• The extra weight helps them dive as deep as 250 feet to search for food. They can stay underwater for up to five minutes.

• Because their bodies are heavy relative to their wing size, loons need a 100-to-600-foot "runway" in order to take off from a lake.

• Loons can fly more than 75 mph.

• The red in the loon's eye helps the bird to see underwater.

• Scientists think loons can live for 30 years or more

How to help protect loons

• View loons from a respectful distance of at least 200 feet

• Respect slow or no wake zones and rules

• Don't fish next to a loon

• Use non-lead fishing tackle

• Check your boat for aquatic invasive species

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