Fauna
Mammal

Giant Otter

Pteronura brasiliensis

Also known as Giant River Otter, River Wolf

Giant otters are the top aquatic predators of South America's rivers and wetlands, easily recognized by their massive bodies, velvet-brown coats, and unique throat patches that act like individual fingerprints. Living in highly vocal, cooperative family groups led by a dominant breeding pair, they hunt fish continuously throughout the day using keen vision and sensitive whiskers. Their territorial river banks feature cleared campsite areas and communal latrines, which serve as vital social signaling hubs.

DiurnalAquaticSocial
Giant Otter reference1 / 7
Charles J. Sharp / CC BY-SA 4.0 · cc-by-sa
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EndangeredConservation statusIUCN Red List categoriesLCNTVUENCREWEXEndangeredRed List categories, explained →
Key facts
Diet & preyCichlids, Characin Fish, Catfish
Predators
  • Black Caiman
  • Jaguar
  • Green Anaconda
ThreatsHabitat loss, water pollution from gold mining, human encroachment, and historical pelt poaching
HabitatsTropical freshwater rivers, streams, slow-moving creeks, and flooded forest lakes
Life span8–12 years in the wild (up to 17 years in captivity)
Classification
  1. OrderCarnivora
  2. FamilyMustelidae
  3. GenusPteronura
  4. SpeciesPteronura brasiliensis
Range & activity
Native
Safe observation
Interaction riskHigh
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is high
Capable of delivering powerful, dangerous bites when protecting young or territory; maintain a safe distance from boats.
Why it is dangerous
Equipped with extremely powerful jaws and sharp teeth designed to crush thick fish scales and bones, capable of inflicting severe wounds.
How to recognize a risky encounter
Look for a massive brown body reaching up to 1.8 meters, a flattened paddle-like tail, and prominent cream-colored neck patches.
What to do
Always remain in a boat at a respectful distance of at least 50 meters and never attempt to swim near or feed wild otters.
What to notice
Identified by loud percussive chuffing or barking calls along river edges and distinctive cream patches on the throat.
Support conservation
Keep motorized watercraft slow and quiet near active dens or campsites to avoid disrupting breeding pairs and vulnerable pups.
Responsible observation
  • Keep distance: Maintain at least 50 meters between your watercraft and otter family groups to avoid causing stress.
  • Listen carefully: Pay attention to loud chuffs, barks, or hums that signal family location or defensive warnings.
  • Watch campsite areas: Look for cleared riverbanks with flat mud pads where groups rest, groom, and mark territory.
Related species
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