Loon

A primitive-looking diving bird of northern lakes with a haunting yodeling call, awkward on land but exceptional underwater — the official bird of Ontario and a symbol of northern wilderness.

A bird of bones

Most birds have hollow bones to reduce weight for flight. Loons have solid bones — a major exception that aids deep diving by reducing buoyancy. The trade-off is that loons are heavy fliers; they need long water runways (up to 90 m) to take off and can’t lift off from land at all.

If a loon lands on wet pavement (mistaking it for water), it’s stranded — unable to take off without a long water run. Wildlife rescue calls for stranded loons happen periodically across northern North America after rainstorms.

Underwater specialist

Loons are among the most accomplished diving birds:

Diving depth typically 60 m, with records over 75 m.
Can stay submerged for up to 3 minutes, occasionally over 8 minutes.
Use feet (not wings) for propulsion underwater — feet are positioned far back on the body for maximum thrust, which is why loons are so awkward on land.
Dense feathers compress under pressure, reducing buoyancy further.

A loon underwater is a focused predator — chasing fish through clear lakes with sustained agile pursuit.

Vocal repertoire

The loon’s haunting calls are among the most recognizable sounds in northern wilderness. The four-call vocabulary is documented:

Wail — a long, mournful, two-note rising whistle, used for long-distance contact between mates.
Tremolo — a wavering “laugh” used as an alarm call.
Yodel — a complex rising call given only by territorial males.
Hoot — a soft, short call used between family members.

Each loon’s yodel is individually distinctive — researchers can identify specific birds by their yodels.

Plumage transformation

Breeding-season loons in summer have striking black-and-white checkered backs, glossy black heads, and red eyes — one of the more dramatic plumages in North American birds. Winter loons are drab gray, almost unrecognizable as the same species. The breeding plumage is what most people recognize as “the loon.”

Mercury accumulation

Loons sit at the top of freshwater food chains and accumulate mercury and other persistent pollutants in their tissues. Loon populations are routinely monitored as bioindicators for water quality across northern North America. Reduced reproduction in some populations has been linked directly to mercury contamination from coal-fired power plants.