Common and yellow-billed loons live on large, clear lakes. In winter, loons generally migrate south, sheltering along the Pacific and Atlantic coasts of North America and Eurasia, on the Great Lakes, the Mediterranean and Black sea regions, and on inland waters. They may also prey on small amphibians, crustaceans, aquatic insects, and other invertebrates along with some plants. Breeding Loons were once thought to form pairs for life. However, studies reveal that they may choose new mates after failed nestings.
Loons return to the same lake and even the same nest year after year.
Red-throated loons may nest in loose colonies, though both parents vigorously defend the territories around their nests from other loons. Other loon species don't even tolerate other loon pairs within sight. A small lake usually hosts just one pair of loons, though more may live on a larger lake, each pair occupying a certain bay or section. Loons challenge intruders with raised neck, alarm or territorial calls, splash-dives and long chases on the water. Red-throated loons also display additional behaviors.