Twelve sperm whale facts, fact-checked
The sperm whale (Physeter macrocephalus) is the largest toothed predator alive and the deepest-diving mammal in routine use of the abyss. Full profile in our sperm whale guide.
1. The loudest animal on Earth
Echolocation clicks reach around 230 decibels underwater — powerful enough to be dangerous at close range.
2. The largest brain of any animal
Around 7–9 kg, roughly five times a human brain.
3. They dive beyond 2,000 m
Routinely hunting at depths sunlight never reaches, holding their breath for over an hour.
4. The head is a sound machine
The spermaceti organ focuses and directs clicks, and may also assist buoyancy control during deep dives.
5. Spermaceti drove the whaling industry
Mistaken for reproductive fluid — hence the name — the waxy oil lubricated machinery and lit lamps for a century.
6. They hunt giant squid
Sucker scars on sperm whale skin were the first hard evidence that giant squid existed.
7. Clans have dialects
Distinct patterns of clicks called codas identify clan membership, and clans with different codas avoid associating.
8. They sleep vertically
Drifting head-up or head-down in still groups near the surface, in short bouts.
9. Females and calves stay together for life
Matrilineal units share calf care, while males leave and roam alone in colder water.
10. Ambergris comes from their gut
A rare intestinal secretion, historically prized in perfumery and still valuable — and legally restricted in many countries.
11. Whaling removed most of them
Centuries of hunting sharply reduced the population; the species remains Vulnerable.
12. Their faeces fertilise the ocean
Deep feeding and surface defecation moves nutrients upward, stimulating plankton growth that captures carbon.
Read the full sperm whale wildlife guide for IUCN status, population context and sources — or donate to WARN to help fund the partner teams protecting wildlife on the ground.
