Where does it get its name?
The name of the sperm whale comes from the waxy substance, called spermaceti, found in their head. Two large oil-filled compartments, known as the “spermaceti organ” and “junk” make up the majority of their head or “melon”. (Panagiotopoulou et al. 2016)
Whale SENSE Region Found:
Endangered throughout its range
Protected throughout its range
Where to watch:
Rare to see on a whale watch in Alaska or the Greater Atlantic. Typically found in offshore areas with depths greater than 600 meters. They are relatively uncommon in waters less than 300 meters deep.
What to watch for:
Blow: Blow on left side of head. Sperm whales are the only living cetacean that has a single blowhole asymmetrically situated on the left side of the crown of the head.
Diving: Paddle-shaped fluke that is small compared to the size of the body. On average, dives will last about 45 minutes. After long, deep dives, individuals come to the surface to breathe and recover for approximately nine minutes
Body: mostly dark grey with an extremely large head that accounts for about one-third of total body length.
Size: Length: 40 feet (females) to 52 feet (males), Weight: 15 tons (females) to 45 tons (males)
Sperm whales mostly prey on squid, sharks, skates, and fish. They are known for going on deep dives averaging about 2,000 feet. Sperm whales can consume about 3 to 3.5 percent of their body weight per day, or approximately 900 kg (almost 2,000 pounds) of food.
Mating and Calving
- Female sperm whales reach sexual maturity around 9 years of age and they produce a calf approximately once every five to seven years. After a 14 to 16-month gestation period, a single calf about 13 feet long is born. Although calves will eat solid food before one year of age, they continue to nurse for several years.
- Males reach physical maturity around 50 years and when they are 52 feet long. Unlike females, puberty in males is prolonged, and may last between ages 10 to 20 years old. Even though males are sexually mature at this time, they often do not actively participate in breeding until their late twenties.
Most females will form lasting bonds with other females of their family, and on average 12 females and their young will form a social unit. While females generally stay with the same unit all their lives in and around tropical waters, young males will leave when they are between 4 and 21 years old and can be found in “bachelor schools,” comprised of other males that are about the same age and size. As males get older and larger, they begin to migrate toward the poles and slowly bachelor schools become smaller; the largest males are often found alone. Large, sexually mature males that are in their late 20s or older will occasionally return to the tropical breeding areas to mate.
Did you know?
- Sperm whales are the largest of the toothed whales.
- They are masters of the deep: Sperm whales typically hunt at 2,000 feet and can last for 45 minutes. They are capable of reaching depths of over 10,000 feet for over 60 minutes in a single dive.
- The white whale in Moby Dick was based on two real-life sperm whales: a whale that rammed and sank the ship Essex and an albino adult male named Mocha Dick.
- All of the sperm whales in the world descended from just one female who lived tens of thousands of years ago.