The penguin dance is generally combined with frantic calls and is one of the last defensive actions available to loons. Anyone observing such a response should retreat immediately. With their young on their backs, the adult loon can provide better protection from predators both above and beneath the water's surface. This is an opportunity for the young to conserve energy and body heat. Loons are believed to mate for life, but more research is needed in this area.
Courtship consists mainly of head dipping and shallow dives.
In spring, loons are frequently observed chasing each other across the surface of a lake. This is primarily territorial behavior, not courtship ritual. The nest consists of reeds, sticks, grasses and muddy vegetation from the bottom of lakes. This material is loosely formed in the shape of a mound, roughly 1.5 feet in diameter, with a slight hollow in the middle. Both the male and female participate in nest building which is completed by mid-May.