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What is a Common Merganser (Mergus merganser)

The Common Merganser (Mergus merganser) is a striking and fascinating species of diving duck, known for its distinctive appearance and exceptional diving abilities. In this article, we will explore the biology, taxonomy, behavior, and distribution of this captivating waterfowl, providing a comprehensive understanding of its unique adaptations and ecological significance.

Common Merganser (Mergus merganser) Overview

The Common Merganser, also known as the Goosander, is a large, fish-eating duck belonging to the family Anatidae. These ducks are well-adapted to life in both freshwater and saltwater habitats, showcasing a range of specialized features that enable them to efficiently hunt and consume aquatic prey.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Aves
  • Order: Anseriformes
  • Family: Anatidae
  • Genus: Mergus
  • Species: Mergus merganser

Size and Body Description

Common Mergansers are sizeable birds, with males typically measuring between 58-72 cm (23-28 inches) in length and females slightly smaller at 51-62 cm (20-24 inches). Males are easily recognizable by their dark green head, bright red beak, and white body with black accents, while females sport a reddish-brown head, greyish body, and a red beak with a serrated edge. Both sexes have long, slender bodies and powerful wings, which enable them to dive and swim efficiently underwater in pursuit of prey.


The primary food source for Common Mergansers is fish, making them adept piscivores. Their serrated beaks enable them to firmly grip slippery fish, while their excellent underwater vision allows them to effectively hunt in both clear and murky waters. Occasionally, they may also consume crustaceans, mollusks, and aquatic insects.


Common Mergansers are monogamous, with pairs forming in late winter or early spring. Nesting occurs in tree cavities, nest boxes, or sometimes even in abandoned burrows of other animals. Females lay an average of 8-12 eggs and incubate them for about 28-32 days. Once hatched, the ducklings are precocial, able to swim and feed themselves almost immediately. They fledge within 60-70 days after hatching.

Where Found

These adaptable birds are found across North America, Europe, and Asia, typically residing near freshwater lakes, rivers, and streams. During winter months, Common Mergansers may migrate to coastal areas, estuaries, and other ice-free bodies of water.

How Long do Common Merganser (Mergus merganser) Live

Common Mergansers have a relatively long lifespan for a duck species, with some individuals living up to 13 years in the wild. However, their average lifespan is typically around 5-7 years, due to various factors such as predation, disease, and habitat loss.

The Common Merganser (Mergus merganser) is an intriguing and highly specialized diving duck, playing a vital role in maintaining the balance of aquatic ecosystems. With their captivating appearance, fascinating hunting abilities, and wide distribution, these ducks offer a remarkable glimpse into the beauty and complexity of the natural world. By understanding and appreciating the Common Merganser’s unique characteristics, we can better contribute to their conservation and ensure their continued presence in our world’s diverse aquatic habitats.