# Sperm Whale — Facts, Threats & Conservation

*Physeter macrocephalus (Linnaeus, 1758)*

> The sperm whale (Physeter macrocephalus) is a Vulnerable deep-diving toothed whale — the largest brain of any animal — hunting squid in abyssal depths after centuries of commercial whaling depletion.

**IUCN status:** Vulnerable (IUCN)  ·  **WARN range:** All deep oceans — from poles to equator

## Quick facts
| Fact | Value |
| --- | --- |
| IUCN status | Vulnerable |
| Type | Largest toothed whale |
| Brain | Largest of any known animal |
| Dive depth | 2,000–3,000 m |
| Diet | Deep-sea squid and fish |
| CITES | Appendix I |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Family:** Physeteridae
- **Species:** Physeter macrocephalus

## Conservation status
- **Status:** Vulnerable globally due to historic whaling depletion; populations recovering slowly in some regions.
- **Population:** Roughly 100,000–300,000 mature individuals
- **Trend:** Increasing slowly in some areas; data poor globally
- **Assessed:** 2008
- **CITES:** Appendix I
- Pre-whaling population may have exceeded one million individuals.

## Key facts: Sperm Whale
- Sperm whales have the largest brain of any known animal — up to nine kilograms.
- Moby-Dick immortalised sperm whaling; industrial hunting killed an estimated one million.
- Females live in lifelong social units; mature males roam solo or in bachelor groups.
- Echolocation clicks stun prey and communicate across kilometres.
- Deep-sea plastic and chemical pollution accumulates in long-lived predators.
- Whale-watching and conservation tourism support protection in Azores and Dominica.

## Head, oil and deep diving
The sperm whale's head comprises up to one-third of body length, housing the spermaceti organ — a wax-filled chamber once mistaken for sperm. Whalers hunted sperm whales heavily for oil used in lamps and industry until petroleum replaced it.

Dives typically last 30 to 60 minutes, reaching depths where pressure exceeds 200 atmospheres. Collapsible lungs and rib cages prevent barotrauma. Prey includes giant squid, colossal squid and deep fish — often bearing circular sucker scars on whale skin.

The lower jaw is narrow and studded with conical teeth; suction feeding may supplement biting.

## Social structure and culture
Females and calves form clans of roughly 15 animals in tropical and subtropical waters, babysitting and nursing communally. Mature males migrate toward poles, growing far larger and eventually leaving natal units.

Clans share distinct click dialects — cultural markers passed socially. Some researchers argue sperm whale culture rivals cetacean complexity outside humans.

Stranding events sometimes involve entire family groups, suggesting strong social bonds that complicate rescue.

## Whaling legacy and modern threats
Industrial whaling peaked in the nineteenth and twentieth centuries, removing perhaps one million sperm whales globally. The IUCN assessed the species as Vulnerable in 2008 with hundreds of thousands remaining — far below pre-whaling abundance.

Modern threats include ship strikes, entanglement in longline and gillnet gear, ingestion of marine debris and noise from seismic surveys interfering with echolocation.

International Whaling Commission moratoria protect sperm whales; Japan historically took limited numbers under objection provisions. CITES Appendix I bans commercial international trade.

## Sperm whales and people
Literature, film and museum skeletons keep sperm whales in public imagination. Ethical whale-watching in the Azores, Dominica and Sri Lanka generates income when boats maintain respectful distance during nursing groups.

Deep-sea mining proposals threaten abyssal ecosystems sperm whales depend on — a frontier conservation issue.

Readers support sperm whales through marine protected areas, reduction of plastic pollution and advocacy against renewed commercial whaling.

## Related WARN guides
Sperm whales are deep-diving toothed giants — read WARN's blue whale guide for baleen comparison, orca and dolphin pages for other odontocetes, and the whale hub for cetacean overview.

Giant squid prey links sperm whales to octopus guide readers exploring ocean depth.

Whaling legacy informs modern ship-strike and sonar threats every cetacean faces.

## What WARN does
WARN's educational reach includes Brazil and Colombia — nations with Atlantic waters where sperm whales migrate. Free guides connect deep-ocean predators to the habitat protection mission shared across our partner countries.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

## Frequently asked questions: Sperm Whale
### Are sperm whales endangered?
The IUCN lists sperm whales as Vulnerable globally — depleted by whaling but not facing immediate extinction. Recovery is slow due to long lifespans and low birth rates.

### What do sperm whales eat?
Mainly squid, including giant and colossal squid from deep water, plus deep-sea fish and occasional sharks.

### Why is it called a sperm whale?
Whalers named the spermaceti organ in the head; the waxy oil was thought to resemble semen. The organ likely aids buoyancy and echolocation.

### How deep do sperm whales dive?
Beyond 2,000 metres routinely, with recorded dives approaching 3,000 metres — some of the deepest mammal dives known.

### Where do sperm whales live?
All deep oceans worldwide. Females prefer warmer waters; large males range into polar feeding grounds.

### Is Moby Dick a sperm whale?
Yes. Herman Melville's novel centres on a white sperm whale, reflecting nineteenth-century American whaling that targeted the species heavily.

## Sources
- [IUCN Red List — sperm whale](https://www.iucnredlist.org/species/41755/160983780)
- [Smithsonian Ocean — sperm whale](https://ocean.si.edu/ocean-life/marine-mammals/sperm-whale)
- [Encyclopaedia Britannica — sperm whale](https://www.britannica.com/animal/sperm-whale)
- [Wikipedia — Sperm whale](https://en.wikipedia.org/wiki/Sperm_whale)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/sperm-whale