ENEndangeredPartial review

Giant Otter

Pteronura brasiliensis

Two giant otters (Pteronura brasiliensis) in the water.

Giant otters (Pteronura brasiliensis).

Image: Charles J. Sharp, CC BY-SA 4.0, via Wikimedia Commons.

At a glance

IUCN category
EN · Endangered
Animal group
Mammals
Population trend
Decreasing
Last verified

Conservation overview

The giant otter is the largest otter in the world, a social river predator of tropical South America. It is assessed as Endangered.

Family groups are noisy and conspicuous, fishing together in rivers and oxbow lakes of the Amazon and Pantanal.

Range & habitat

Rivers and wetlands of tropical South America, centred on the Amazon basin and the Pantanal.

Major threats

Threats below are drawn from the authoritative sources listed on this page. For the current, complete assessment, see the IUCN Red List.

  • Habitat degradation and deforestation
  • Historical hunting for pelts
  • Pollution including mining-related mercury

Why it matters

As a top predator of South American waterways, the giant otter reflects the health of those freshwater systems.

Giant otter eating a fish in a Brazilian river.

A giant otter feeding — Endangered in the wild.

Image: Giles Laurent, CC BY-SA 4.0, via Wikimedia Commons.

Sources

Sources for Giant Otter

Frequently Asked Questions

Why is the giant otter Endangered?
Published assessments cite habitat degradation, historical hunting for pelts, pollution, and conflict with fisheries.
How big is a giant otter?
It is the longest member of the weasel family, noticeably larger than the otters familiar from Europe and North America.

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