# Pink River Dolphin — Facts, Threats & Conservation

*Inia geoffrensis*

> A pink river dolphin (Inia geoffrensis), also called the boto or Amazon river dolphin, is a freshwater toothed whale native to the Amazon and Orinoco river systems of South America. It is the largest river dolphin, named for the pink colouring adults often develop, and is classed as Endangered by the IUCN.

**IUCN status:** Endangered (IUCN, 2018) — assessed as one species with three subspecies  ·  **WARN range:** Brazil, Colombia

## Quick facts
| Fact | Value |
| --- | --- |
| Lifespan | Up to ~30 years (recorded in captivity) |
| Weight | Up to ~185 kg (males); females ~100 kg |
| Length | Up to ~2.5 m (males); largest of all river dolphins |
| Diet | Carnivore — 50+ fish species, plus turtles, crabs, small caimans |
| Gestation | About 11 months |
| Young per birth | 1 calf (~80 cm at birth) |
| Baby name | Calf |
| Group name | Pod (usually seen alone or in small groups of a few individuals) |
| CITES | Appendix II |
| IUCN status | Endangered (2018) |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla (infraorder Cetacea)
- **Family:** Iniidae
- **Genus:** Inia
- **Species:** Inia geoffrensis (Blainville, 1817)
- **Note:** Three subspecies are usually recognised: I. g. geoffrensis, I. g. boliviensis and I. g. humboldtiana; some authorities treat the Bolivian form as a separate species, Inia boliviensis.

## Conservation status
- **Status:** Endangered
- **Population:** No reliable rangewide estimate; thought to number in the tens of thousands
- **Trend:** Decreasing
- **Assessed:** 2018
- **CITES:** Appendix II
- Reclassified from Data Deficient to Endangered in 2018; a 22-year study in Brazil's Mamiraua Reserve recorded an annual decline of about 5.5%. The species is also listed on CMS Appendix II.

## Key facts: Pink River Dolphin
- The pink river dolphin is the largest freshwater dolphin on Earth, reaching about 2.5 m and up to roughly 185 kg.
- Adults, especially males, turn pink — the colour comes largely from scar tissue built up through rough play and fighting, intensified by exertion.
- Unfused neck vertebrae let it turn its head nearly 90 degrees to hunt fish among submerged tree roots in the flooded forest.
- It is Endangered (IUCN, 2018), with a long-term study in a protected reserve recording an annual decline of about 5.5%.
- Main threats are drowning in gillnets, deliberate killing for use as catfish bait, and mercury contamination from illegal gold mining.
- There is no reliable rangewide population estimate; numbers are thought to run into the tens of thousands but are decreasing.

## Why it is endangered
Once thought to be naturally protected by local taboos, the boto is now in steep decline across much of its range. A 22-year monitoring study in Brazil's Mamiraua Reserve — one of the better-protected parts of its range — recorded the population falling by roughly 5.5% every year, a rate fast enough to halve numbers within little more than a decade. On the strength of evidence like this, the IUCN reclassified the species as Endangered in 2018, having previously listed it as Data Deficient. Because the dolphins are spread thinly across vast, hard-to-survey river networks, there is no trustworthy global population figure — the honest answer is that no one knows exactly how many remain, only that the trend is downward.

## Behaviour and ecology
Botos are superbly adapted to murky, obstacle-filled freshwater. They navigate and hunt by echolocation, emitting clicks to find prey in water where eyesight is almost useless. Their stocky bodies carry a low ridge rather than a tall dorsal fin, and uniquely flexible, unfused neck vertebrae let them twist and reach into flooded forest to take fish, river turtles, crabs and even small caimans — one of the widest diets of any toothed whale. During the annual flood season they swim among the trees, dispersing through the forest before returning to main river channels as waters fall. Calves are born singly after about an 11-month gestation, measuring around 80 cm, and stay with their mothers for a year or more.

## Threats
The boto's decline is overwhelmingly human-driven. Many drown after becoming entangled in nylon gillnets, while others are deliberately harpooned to be used as bait for piracatinga, a scavenging catfish. Layered on top is mercury pollution: illegal gold mining releases the metal into rivers, where it accumulates up the food chain into these long-lived top predators. Dams fragment populations and block movement, and extreme events tied to a warming climate add new dangers — in 2023, scores of botos died in a single Amazon lake during a record drought and heatwave. Together these pressures make the freshwater habitat itself the front line for the species' survival.

## What rescue and protection involve
Protecting botos is mostly about protecting rivers and the people who share them. Practical work includes removing or modifying deadly gillnets, supporting fishers to abandon the bait-hunting trade, monitoring mercury levels, responding to stranded or entangled animals, and safeguarding key stretches of flooded forest. Because the dolphins cross national borders, lasting gains depend on locally led teams who know the waterways and can build trust with riverside communities — the kind of frontline partners that conservation funders increasingly back rather than parachuting in from outside.

## Pink river dolphin vs the grey tucuxi: two Amazon dolphins compared
| Feature | Pink River Dolphin (Inia geoffrensis) | Tucuxi (Sotalia fluviatilis) |
| --- | --- | --- |
| Family | Iniidae (true river dolphin) | Delphinidae (oceanic dolphin lineage) |
| Adult length | Up to ~2.5 m | Up to ~1.5 m |
| Colour | Grey turning pink with age | Grey above, paler below; never pink |
| Dorsal fin | Low ridge, no true fin | Distinct triangular dorsal fin |
| Neck | Flexible, unfused vertebrae | Stiffer, fused neck |
| IUCN status | Endangered (2018) | Endangered (2020) |

## What WARN does
WARN CIC is a registered global not-for-profit animal welfare organisation that funds local partner shelters, sanctuaries and rescue teams in Pakistan, Indonesia, Malaysia, Brazil and Colombia. The pink river dolphin's range spans six South American countries, but two of them — Brazil and Colombia — sit squarely within WARN's funded focus. There, WARN's model is to channel support to in-country partners working on river-dolphin safety: reducing gillnet bycatch, discouraging the bait-hunting trade and protecting flooded-forest habitat. Across the wider Amazon and Orinoco basins, WARN's contribution is education and awareness, amplifying the work of those closest to the water rather than overstating a presence it does not have.

Botos live or die by the health of their rivers. A gift to WARN helps fund the local partners in Brazil and Colombia working to clear deadly gillnets and protect the flooded forests these pink dolphins call home.

## Frequently asked questions: Pink River Dolphin
### How long do pink river dolphins live?
In captivity, healthy Amazon river dolphins have lived to around 30 years; lifespans in the wild are thought to be broadly similar but are not precisely known.

### What do pink river dolphins eat?
They have one of the most varied diets of any toothed whale — more than 50 species of fish, plus river turtles, freshwater crabs and occasionally small caimans, located by echolocation in murky water.

### How big do pink river dolphins get?
They are the largest of all river dolphins. Males reach about 2.5 m long and up to roughly 185 kg; females are noticeably smaller.

### Are pink river dolphins dangerous to humans?
No. Botos are not considered dangerous to people. They are curious and sometimes approach boats, and steep in local Amazon folklore, but there are no records of them harming humans.

### How many pink river dolphins are left?
There is no reliable rangewide count. Numbers are thought to run into the tens of thousands, but monitoring shows the population is declining — by about 5.5% a year in one well-studied protected reserve.

### Why are pink river dolphins pink?
Adults, especially males, develop a pink tone largely from scar tissue built up through rough social play and fighting; the flush can deepen with exertion and warmer water.

### What is a baby pink river dolphin called?
A young pink river dolphin is called a calf. Mothers give birth to a single calf, about 80 cm long, after a gestation of roughly 11 months.

## Sources
- [IUCN Red List — Inia geoffrensis (Amazon River Dolphin), 2018 assessment](https://www.iucnredlist.org/species/10831/50358152)
- [CMS — Inia geoffrensis species profile](https://www.cms.int/en/species/inia-geoffrensis)
- [Oryx (Cambridge) — Amazon river dolphins are on the path to extinction in the heart of their range](https://www.cambridge.org/core/journals/oryx/article/amazon-river-dolphins-inia-geoffrensis-are-on-the-path-to-extinction-in-the-heart-of-their-range/2CB21F19C8D566AD79B3AE5DF77F26D9)
- [PLOS ONE / NCBI — Sustained population declines of two Amazonian cetaceans over two decades](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5931465/)
- [Animal Diversity Web — Inia geoffrensis](https://animaldiversity.org/accounts/Inia_geoffrensis/)
- [SeaWorld / United Parks — Boto (Amazon river dolphin) facts](https://seaworld.org/animals/facts/mammals/boto/)
- [WWF — A new categorization for river dolphins in IUCN's Red List](https://wwf.panda.org/es/?341231/A-New-Categorization-for-River-Dolphins-in-IUCNs-Red-List)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/pink-river-dolphin