The Pygmy Sperm Whale is one of the least known cetaceans in the world, despite not being particularly rare. It lives in the open sea, moves slowly, and avoids contact with vessels. Most of what is known about its biology comes from dead stranded animals on the coast, not from sightings at sea.
It has a defensive trick unusual among mammals: when threatened, it expels a cloud of dark reddish intestinal fluid, very similar to squid ink, which it uses to confuse predators while escaping.
Its square head and small, recessed lower jaw give it an appearance vaguely reminiscent of a shark at the surface. This resemblance has caused more than one confusion among bathers and fishermen.
A small cetacean with a robust body, dark bluish-grey on the back and lighter on the belly. It has a square head with a small lower jaw set far back from the snout, and a clear false gill-slit mark behind the eye, resembling a shark's gill slit. It is confused with the Dwarf Sperm Whale (Kogia sima), which is very similar and smaller.
It leaves no tracks on land. Its behaviour at sea is extremely discreet: it has a low, barely visible blow and surfaces slowly, barely showing its back. This makes it very difficult to detect at sea, even at close range.
When threatened, it can release a cloud of dark reddish intestinal fluid, similar to squid ink. It uses this as a defensive screen before diving to escape. This behaviour is unique among cetaceans and is its most characteristic track and sign.
The vast majority of records for the Pygmy Sperm Whale come from beach strandings, where the body appears with its characteristic square head and recessed jaw.
Deep oceanic waters of the continental shelf and slope, in temperate and tropical waters worldwide. The Pygmy Sperm Whale is rarely observed near the coast, except in stranding events. It is widely distributed globally, though with very few direct at-sea records due to its elusive behaviour.
It feeds mainly on deep-water squid, supplemented by benthic fish and crustaceans, caught during deep dives.
The Pygmy Sperm Whale is solitary or occurs in small, loosely cohesive groups. Its behaviour at the surface is very discreet and elusive, which makes direct study at sea extremely difficult. Its reproductive and social biology remains poorly known compared to other cetaceans.
Direct population data for the Pygmy Sperm Whale are almost entirely lacking. This stems from its elusive behaviour and the fact that most records are of strandings. Consequently, global population trends cannot be reliably determined.
Ingestion of plastic and other marine debris, relatively frequently documented in necropsies of stranded animals, bycatch in high-seas fishing gear, and underwater acoustic pollution, which can interfere with its echolocation.
See all species accounts for even-toed ungulates · Full species index
Mammaling is a free app for logging the mammals you find. You record a sighting in a moment — even if it's just a track — your life list grows, and the record becomes available to scientific and conservation projects.
It runs on your phone with nothing to install. If you like, it adds to your home screen like any other app.
Open Mammaling