Goosander Vs Red-Breasted Merganser: Key Differences Explained

The waters of the United Kingdom are home to two remarkable diving ducks: the Goosander (Mergus merganser) and the Red-Breasted Merganser (Mergus serrator). These elegant members of the sawbill family share fascinating features, including their serrated bills perfectly adapted for catching fish.

Did you know that the Red-Breasted Merganser holds the record for being the fastest duck ever recorded, reaching an astonishing speed of 100 mph? Or that Goosanders only began breeding in the UK relatively recently, with their first recorded breeding in 1871?

Let’s learn more about the key differences between these two remarkable species in this article!

Table of Contents

Key Takeaways

Goosanders are larger, measuring 58-66 cm compared to Red-Breasted Mergansers at 52-58 cm
Male Goosanders have a plain green head, while male Red-Breasted Mergansers sport a distinctive spiky crest
Goosanders prefer freshwater habitats, while Red-Breasted Mergansers are more commonly found in coastal areas
Goosanders nest in tree cavities, while Red-Breasted Mergansers nest on the ground
Red-Breasted Mergansers are more vocal during courtship than Goosanders
Goosanders weigh more, ranging from 900-2,100 g compared to Red-Breasted Mergansers at 900-1,350 g
Goosanders typically lay 8 to 12 eggs, while Red-Breasted Mergansers usually lay 8 to 10 eggs

What Is The Difference Between A Goosander And A Red-Breasted Merganser?

While both species belong to the same genus (Mergus) and share similar fishing adaptations, they differ significantly in their appearance, habitat preferences, and behaviour.

Visual Differences

The most noticeable visual differences lie in their head shapes and plumage patterns.

Male Goosanders have a sleek, glossy green head and a striking blood-red beak, with a clean white body that shows a salmon-pink tinge during the breeding season. Their backs and wings are black, creating a sharp contrast.

Male Red-Breasted Mergansers are distinguished by their spiky crest and dark green head, along with a distinctive rusty-coloured breast band. Their sides are handsomely marked with black and white patterns.

Female Goosanders have a gingery-orange head with a clear delineation from their grey body. Female Red-Breasted Mergansers have a rusty head but show more mottled plumage patterns overall.

Differences In Habitat

Goosanders show a strong preference for freshwater environments, particularly during the breeding season. They frequent upland rivers, lakes, and reservoirs across the UK, occasionally moving to sheltered estuaries during winter.

Red-Breasted Mergansers are more versatile in their habitat selection. While they breed near both freshwater and coastal areas, they show a stronger affinity for coastal waters, especially during winter. They are commonly seen along the UK coastline during the colder months.

Nests & Eggs

These species exhibit distinct nesting preferences and egg characteristics.

Goosanders are cavity nesters, typically choosing tree holes or large nest boxes near water bodies. They lay 8 to 12 cream-coloured eggs in a nest lined with down feathers plucked from the female’s breast.

In contrast, Red-Breasted Mergansers are ground nesters, creating their nests in sheltered locations close to water. They often choose sites with good cover from vegetation, helping to protect their eggs from predators. The female typically lays 8 to 10 eggs that are coloured buff to olive-brown. Like Goosanders, they also line their nests with down feathers.

Both species’ eggs are incubated solely by the female, and the incubation period is similar for both species, lasting around 30 to 32 days. Once hatched, the ducklings of both species are precocial, meaning they can swim and feed themselves shortly after hatching, though they remain under their mother’s protection.

Bird Calls

Both species are relatively quiet outside of breeding season, but their vocalisations differ when they do call.

Goosanders produce a low, harsh croak, with males occasionally emitting a soft whistle during the breeding season.

Red-Breasted Mergansers are more vocal during courtship. Males produce a distinctive meowing sound, while females make a rasping call. Their flight call is characterised by a harsh gruking sound.

Size & Weight

Goosanders are the larger of the two species. They measure 58 to 66 cm in length with a wingspan of 82 to 97 cm. Males weigh 1,300 to 2,100 g, while females are lighter at 900 to 1,700 g.

Red-Breasted Mergansers are notably smaller, measuring 52 to 58 cm in length with a wingspan of 70 to 86 cm. They weigh between 800 to 1,350 g, making them more streamlined than their larger cousins.

Frequently Asked Questions

Which is more common in the UK, the Goosander or Red-Breasted Merganser?

Both species are resident in the UK, but Goosanders are more commonly seen inland on freshwater bodies, while Red-Breasted Mergansers are more frequently observed along coastal areas.

How can you tell a Goosander from a Red-Breasted Merganser?

The easiest way to distinguish between them is by looking at the head shape and breast colouring. Goosanders have a smoother head profile and clean white breast, while Red-Breasted Mergansers have a spiky crest and rusty-coloured breast band.

Do Goosanders and Red-Breasted Mergansers compete for food?

While both species feed primarily on fish, they often avoid competition by utilising different habitats, with Goosanders preferring freshwater environments and Red-Breasted Mergansers favouring coastal waters.