Sperm Whale (Physeter macrocephalus)
– to a maximum length of 18 metres
– dark brownish gray, with skin that looks wrinkled, like a prune
– more of a rounded hump, it sits 2/3 back from the head.
– low bushy blow, projected forward and to the left, usually less than 2 metres in height, very distinct
– each half of the tail is the shape of a right triangle, with a distinctive V notch in the middle
– the huge square shaped head is distinctive, is sometimes referred to a ‘boxcar’
– skin appears ‘wrinkled’
– Males are typically 30% to 50% longer (16-18 m, 52–59 ft) than females (12-14 m, 39–46 ft) and are twice as massive (50 000 kg vs. 25 000 kg, 55 short tons vs 27.5 short tons) the most dramatic example of sexual dimorphism in cetaceans.
Can Be Confused With
– head shape is so distinctive, is not easily confused with other large whales
Sperm whales are the largest of the toothed whales and the largest living carnivore. Their distinctive shape comes from their very large head, particularly in males, which is typically one-third of the animal’s length. The species name macrocephalus is from the Greek for “big head”. The common-name, sperm whale, refers to the waxy oil known as spermaceti, which is found in this species’ head, Spermaceti is a high-quality oil and was used originally in lamp oil and later as an industrial lubricant, in cosmetics, automatic transmissions and pharmaceutical compounds; making this species highly valuable to whalers.
Sperm whales have 20–26 pairs of cone-shaped teeth in their narrow lower jaw. Each tooth is 10 to 20 cm long and can weigh as much as one kilogram. However, the existence of teeth in sperm whales is a bit of a mystery as the teeth are not considered to be necessary for feeding on their primary food item, giant squid. Sperm whales dive to depths of up to 1 km to locate these rarely seen squid; although, most dives are to ~400 metres and last for 35 min to 1 hour. After a long dive, sperm whales remain at the surface for around 8 minutes. It is during this time that sperm whales were most susceptible to whalers.
At least 6,069 sperm whales were taken by B.C. whalers between 1908 and 1967. They are now seen rarely in coastal BC (There are 278 sperm whale sightings in the BCCSN database as of 2007, representing 0.7% of all sightings).
STATUS IN CANADA
COSEWIC Not at Risk (1996)
Reason for Designation
Sperm whales range widely through the world’s oceans and males are found off both coasts of Canada. The worldwide population is reasonably large despite historical large reductions by commercial whaling. Whaling for this species was discontinued in 1972 in Canada, and 1968 in BC.