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Sperm Whale

Physeter macrocephalus

Biggest brain on Earth, loudest voice in the animal kingdom, hunts giant squid in the dark.

Vulnerable
2,000 mdeep on their longest dives

A sperm whale is a submarine with teeth. It dives a kilometre down into water so black that sight is useless, finds a giant squid using sound alone, and comes back up an hour later to breathe.

On the conservation status

Whaling took an estimated one million sperm whales. Their oil lit lamps and lubricated machines for over a century.

Length
Males up to 18 m (59 ft)
Weight
Up to 57,000 kg (63 tons)
Lifespan
60–70 years
Diet
Squid, including giant squid
Brain
7.8 kg — the largest on Earth
Dive time
60–90 minutes
Six things worth knowing

The good stuff.

01

The loudest animal alive

Their echolocation clicks hit 230 decibels underwater. That is louder than a rocket launch. The clicks are focused into a beam and used to find squid hundreds of metres away in total darkness.

02

A third of the body is head

Inside is the spermaceti organ, full of waxy oil, which works as a giant acoustic lens to focus those clicks. Whalers thought the oil was something else entirely — which is where the unfortunate name came from.

03

They fight giant squid

Sperm whales surface with round scars all over their heads, left by the hooked suckers of giant and colossal squid. Nobody has ever filmed one of these fights.

04

They sleep standing up

Whole pods have been photographed floating vertically, nose to the surface, completely still, like a forest of whales. They only nap about seven minutes at a time.

05

Families have surnames

Sperm whale clans use distinct patterns of clicks called codas. Two clans can share the same water and never mix, and a calf learns its clan's coda the way you learn an accent.

06

Babysitting is a real job

Calves can't dive as deep as adults, so while mum hunts a kilometre down, another adult in the group stays at the surface to guard the baby.

Quick curiosities

Wait, really?

  • Ambergris — a rare, waxy substance from a sperm whale's gut — was once worth more than gold to perfume makers.

  • Moby Dick was based on a real white sperm whale, Mocha Dick, and on the sinking of the whaleship Essex in 1820.

  • Their heart rate drops to a handful of beats per minute on a deep dive to save oxygen.

What it sounds like

Sharp, rifle-crack clicks in rhythmic patterns — more Morse code than music.

Where you might see one

The Azores, Kaikōura in New Zealand, Dominica, and northern Norway.

What's hurting them

The trouble

  • Entanglement in deep-sea fishing gear
  • Ship strikes
  • Swallowed plastic
  • Ocean noise from sonar and seismic surveys
What you can do

One real thing

Cut plastic at the source. Sperm whales have been found dead with dozens of kilos of bags and rope in their stomachs.

More ways to help