Mergus – Typical mergansers

The genus Mergus, commonly known as the typical mergansers, includes a group of diving ducks renowned for their sleek bodies and specialized fish-catching skills. These waterfowl are found in freshwater lakes, rivers, and coastal regions across North America, Europe, and Asia. The genus consists of species like the common merganser (Mergus merganser), red-breasted merganser (Mergus serrator), and the critically endangered Scaly-sided merganser (Mergus squamatus). What sets these ducks apart is their slender, serrated beaks, often described as “saw-billed,” which help them grip slippery fish, their primary food source. These adaptations make them efficient hunters in aquatic habitats.

Mergansers are medium to large ducks, with males and females often differing in appearance. Males typically display striking plumage during the breeding season, such as a glossy green head, bright red beak, and white body in the common merganser, while females usually sport subtler colors like gray with a reddish-brown head. This sexual dimorphism helps males attract mates while females remain camouflaged during nesting. Despite their differing looks, both sexes are adept swimmers and divers, using their webbed feet to propel themselves underwater as they chase fish.

These ducks are highly migratory, with many species traveling long distances between their breeding and wintering grounds. During the breeding season, mergansers prefer forested regions near freshwater lakes or rivers with plenty of fish. Females often nest in tree cavities, using their downy feathers to line the nest and keep their eggs warm. After the ducklings hatch, they are remarkably independent, often leaving the nest within a day to follow their mother to the water. These tiny, fluffy ducklings quickly learn to dive and catch small aquatic prey, a skill they will need to survive.