The common loon is one of Canada's best-known birds and appears on the country's one-dollar coin, which Canadians fondly call the loonie. A large diving bird of northern lakes, it has a sleek black head, a checkered black-and-white back, and a string of pale markings around its throat. Its wild, wavering call carries far across the water on a still evening and is, for many, the very sound of a Canadian summer. Once common on lakes throughout the south, the loon was pushed out of many of them by shoreline development and pollution before cleaner water and careful protection let it return to much of its former range.
The loon is built for diving in a way that sets it apart from most other birds. Where the bones of a typical bird are hollow and light for flight, many of the loon's bones are solid and dense, which cuts its buoyancy and lets it slip below the surface to chase fish in deep, cold water. Its legs sit far back on its body, driving it powerfully through the water though leaving it clumsy and almost helpless on land. For this reason a loon comes ashore only to nest, choosing a spot at the very edge of the water where it can push off again with ease.
