Found on quiet lakes across nearly every province, the common loon is among the most recognizable of Canada's water birds and, of all the country's wildlife emblems, is perhaps the most familiar. It appears on the one-dollar coin that Canadians now call the "loonie." In its summer plumage the bird wears a glossy black head, a checkered black-and-white back, and a ring of pale markings around the throat, while its eyes turn a striking deep red. Adults weigh roughly two to three kilograms and stretch close to a metre from bill to tail, larger than most of the ducks that share their waters. The loon is built for the water rather than the land, and its legs sit so far back on its body that walking is clumsy, though the same design makes it a powerful swimmer.

The loon is celebrated above all as a diver. Unlike most birds, whose bones are hollow and light, the loon has largely solid bones that reduce its buoyancy and let it slip beneath the surface with ease. Chasing fish, it can plunge to depths of many metres and stay under for a minute or more, steering with its webbed feet and seizing prey in its dagger-like bill. To take flight, a loon needs a long stretch of open water, running across the surface and beating its wings before it finally lifts into the air. These same lakes echo at dusk with the bird's wavering call, a sound so tied to the northern night that recordings of it are used the world over to suggest wilderness.