The winters in northern climates are too cold for loons. They depend on fish to eat and since the lakes freeze over during the winter they must move south to find food. Loons mostly eat fish such as yellow perch, trout, and minnows. They will also eat mollusks, insects, frogs, and crayfish. Loons are terrific divers and their bodies have adapted to their aquatic lifestyle.
Most birds have hollow bones to reduce weight to make flying easier.
Loons have solid bones, which makes them denser than water therefore making it easier to dive deep into the water. Loons breed in the summer and both parents spend equal time sitting on the nest incubating the two brown eggs. Their nests are on a mound by the water's edge. Both parents help raise the chicks and for the first three weeks the chicks spend most of their time riding on their parents' back. They do this to avoid hungry predators like fish and turtles.