Sperm whales are the largest of all odontocetes and among the deepest diving of all cetaceans - they are known to dive over 1,000 metres and they can stay underwater for over an hour at a time, so you are lucky if you spot them. They are best known through the sperm whale character ‘Moby Dick’ in Herman Melville’s story of the same name.
Sperm whales have a unique appearance with a massive blunt, squared off head that can be up to seven metres long (or one-third the total body length) and a relatively small under-slung jaw. Adult males can grow up to between 15 to 18 metres long and weigh 35 tonnes while females can grow to 11 metres long and weigh up to 14 tonnes.
Sperm whales have a single blowhole on the left side of their head and it sits facing forward causing their bushy blow to project forwards rather than straight up in the air. Their bodies have a wrinkled and shriveled appearance especially behind the head.
Sperm whales mostly eat deep water squid but also feed on fish, skate and octopus. A sperm whale can eat a tonne of food a day.
They have a cosmopolitan distribution but male sperm whales are found mostly in higher latitudes. These males sometimes migrate to lower latitudes, but only the largest males seem to migrate to the equatorial breeding grounds. Females, calves and juveniles remain in the warmer tropical and sub-tropical waters.
Despite being widely hunted during the 19th and early 20th centuries, sperm whale populations remain quite healthy, especially in the southern oceans. Sperm whales are one of the more common stranding species on the coasts of NSW.
To check out the latest sightings of whales along the NSW coastline, visit our latest sightings map.