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Common Loon

Gavia immer

During breeding season, loons have a distinctive plumage: a black head and bill and a black-and-white checkered back and
During breeding season, loons have a distinctive plumage: a black head and bill and a black-and-white checkered back and "necklace" around the throat. (jackanapes/Flickr)

The common loon is a duck-like sea bird with a thick, pointed bill and a distinctive black-and-white checkered pattern during breeding season. It visits the Chesapeake Bay in autumn and late winter to feed on open waters.


  • Appearance varies depending on the time of year
  • During breeding season, loons have a distinctive black-and-white checkered back and “necklace” around the throat. The head and bill are black.
  • In winter, loons have a mostly blackish black and a pale gray bill. The white throat has an irregular black indentation.
  • Thick, dagger-like bill that it holds straight ahead
  • Large, webbed feet
  • Long body that grows 28-36 inches long. The wingspan reaches an average of 58 inches.


  • Lives on the Chesapeake Bay’s open waters


  • Begins arriving on the Chesapeake Bay in late September after migrating from its northern breeding grounds. By October and November, there are thousands of loons on the Bay.
  • As winter draws near, large flocks of loons leave the Bay and continue flying southward to the Outer Banks of North Carolina.
  • In February and early March, loons return to the Bay. At this time, they are in their distinctive breeding plumage. Soon after their arrival, loons begin their migration back to their northern breeding grounds.


  • Feeds heavily on menhaden and other small fish
  • Constantly hunts throughout the day. It peers below the water’s surface to find prey, then dives below the water to chase it down.
  • Loons feast throughout autumn to hold themselves over during their winter molt, when they cannot swim or fly. When they return to the Bay in late winter, loons once again eat large amounts of fish in preparation for their return flight to the north.


  • Adults have few predators, but may be vulnerable to bald eagles and other large raptors
  • May use its spear-like bill to defend itself against predators


  • In flight, loons have a hunchbacked appearance. They hold their bill straight ahead and their large feet trail behind.


  • Mostly silent in winter
  • Makes several distinct calls during other parts of the years, including a quivering wail

Reproduction and Life Cycle:

  • Breeds in Canada and the Great Lakes region of the United States

Other Facts:

  • Can be confused with the double-crested cormorant. You can distinguish a common loon by its spear-like bill, which it holds straight ahead.
  • Loons are very powerful swimmers, but they are clumsy on land because their legs are located far back on the body.

Sources and Additional Information:

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