Identification.
The largest of the toothed whales, mature males average about 15m in length; females about 10m. The body is robust, with a massive, blunt head that comprises almost one-third of the animal's total length. The lower jaw is long, narrow and inconspicuous beneath the head. A single nostril is located on the left side of the front of the head, resulting in a distinctive 'forward' and angled blow. There is no dorsal fin, only a small hump, behind which are a series of knuckles running as far as the tail. Sperm Whales are normally slate grey or brown and the skin is usually wrinkled. The flukes, which are generally raised vertically prior to a sounding-dive, are large and triangular, with smooth edges and a deep central notch.

Similar Species.
Sperm Whale overlaps with several rorquals in size and like Humpback and Blue Whales, raises its flukes before sounding. However, all rorquals are distinguished by their vertical blow, rounded heads and distinctive dorsal fin.

Behaviour.
Sperm Whales are gregarious, often travelling in pods of up to 20 or more, and are usually found in two distinct group types: mixed pods of females/immature males; and groups of bachelor males. They can be quite demonstrative and breach regularly, particularly on the breeding grounds. This species is renowned for diving to tremendous depths where it captures Giant Squid.

Status and Distribution.
The Sperm Whale is widely distributed in deep, offshore waters throughout the world. The mixed pods of females and immature males usually remain in tropical or sub-tropical waters throughout the year. The groups of males travel to higher latitudes, sometimes as far as the ice fields to fed, returning to join the groups of females during the breeding season.

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