Brazilian Merganser

The Brazilian Merganser is a medium-sized duck with a distinctive long, thin, serrated black bill. Its head and upper neck are dark green with a long, shaggy crest. The body is predominantly dark brown above and pale grey below, with darker striping that fades towards the belly.

Males have a more prominent crest and a larger white wing patch than females. Juveniles resemble females but have a duller plumage and a less developed crest.

Brazilian Mergansers are generally quiet birds. Their vocalisations include soft, low whistles and quiet grunts.

During courtship, males produce a series of low, nasal 'rreck-rreck' calls. Alarm calls consist of sharp, high-pitched whistles, often given when disturbed.

• Look for them along fast-flowing, clear rivers with rocky bottoms
• Observe early morning or late afternoon when they are most active
• Listen for their soft, low whistling calls
• Be patient and quiet, as they are easily startled

Brazilian Mergansers primarily feed on small fish, which they catch by diving and pursuing underwater. They also consume aquatic insects, crustaceans, and molluscs.

Their serrated bills are specially adapted for gripping slippery prey in fast-flowing water.

Brazilian Mergansers form monogamous pairs and breed during the dry season, typically from June to August. They nest in natural cavities in trees or rocky crevices near water, often reusing the same site year after year.

The female lays 2-6 cream-coloured eggs in a nest lined with down. Incubation lasts about 32 days, performed solely by the female while the male guards the territory.

After hatching, both parents care for the ducklings, which can swim and dive shortly after birth. The young remain with their parents for several months, learning essential survival skills.

Brazilian Mergansers are excellent swimmers and divers, using their specialised bills to catch fish underwater. They are typically seen in pairs or small family groups, maintaining strong pair bonds throughout the year. These birds are shy and wary, often fleeing at the first sign of disturbance.

The Brazilian Merganser is critically endangered due to habitat loss, water pollution, and dam construction.

Conservation efforts focus on protecting remaining habitats, reducing water pollution, and implementing captive breeding programs to boost wild populations.