The Brazilian Merganser (Mergus octosetaceus) is a critically endangered diving duck found in very isolated populations in central-southern South America. It prefers clear, fast-flowing rivers with forested banks, where it preys on small fish and aquatic invertebrates.
Where to spot
Extremely rare and localized. Found in specific areas of Brazil (Serra da Canastra National Park being a key site), Argentina, and Paraguay, typically in remote, pristine river systems.
How to spot
Look for its dark, sleek appearance, long slender bill, and a small crest on the hindcrown. They are highly agile and often swim low in the water. Listen for their distinctive calls, which can help pinpoint their presence in dense riparian vegetation.
When to spot
Year-round in its restricted range. Observation requires dedicated effort and local knowledge due to its rarity and preference for secluded habitats.
Where to spot
Extremely rare and localized. Found in specific areas of Brazil (Serra da Canastra National Park being a key site), Argentina, and Paraguay, typically in remote, pristine river systems.
How to spot
Look for its dark, sleek appearance, long slender bill, and a small crest on the hindcrown. They are highly agile and often swim low in the water. Listen for their distinctive calls, which can help pinpoint their presence in dense riparian vegetation.
When to spot
Year-round in its restricted range. Observation requires dedicated effort and local knowledge due to its rarity and preference for secluded habitats.
Credits:
Wikimedia Commons
Credits:
Wikimedia Commons
Credits:
Wikimedia Commons
Credits:
Wikimedia Commons
Credits:
Wikimedia Commons
Credits:
Wikimedia Commons
This species is one of the most endangered waterfowl in the world, with an estimated population of fewer than 250 individuals, facing threats primarily from habitat degradation and hydroelectric development.
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