Hooded mergansers often choose tree cavities for nesting, sometimes moving into old woodpecker holes.

Each autumn, the quiet waterways of Oregon, United States, become seasonal waypoints for hooded mergansers—small diving ducks native to North America. They are agile divers, plunging beneath the surface to catch fish and other prey. Males, known as drakes, stand out with their fan-shaped white crests, dark heads and chestnut-brown sides, while females, called hens, are brownish grey with smaller crests. Oregon's lakes and wetlands provide sheltered feeding grounds as these birds migrate or winter across the continent.

Among the six living merganser species, hooded mergansers are the second smallest. They are known for their striking courtship displays, where males raise their crests dramatically to attract mates, creating unmistakable shapes on still water. They nest in tree cavities near wetlands, and soon after hatching, ducklings leap to the ground to follow their mother to water. Classified as Least Concern on the International Union for Conservation of Nature's Red List, their populations remain stable across their range. First described in 1758, their genus name, 'Lophodytes,' means 'crest diver' in Greek—a nod to both their plumage and underwater hunting skill.