Sperm whale
Sperm whales are large marine mammals belonging to the family Physeteridae, with three distinct species: the sperm whale, the pygmy sperm whale, and the dwarf sperm whale. They inhabit oceans worldwide, excluding the Arctic, and can dive up to 560 feet per minute, with their breathing sounds audible from half a mile away. Males are notably larger, reaching lengths of about 52 feet and weighing around 45 tons, while females and smaller species like the pygmy and dwarf sperm whales are significantly smaller.
Sperm whales are carnivorous, feeding on cuttlefish, squid, and occasionally octopus, often sustaining scars from encounters with giant squid. Socially, they live in herds organized by age and sex, with females and young led by a dominant male, while adult males may live solitary lives. Mating occurs in spring and summer, with females giving birth every three to five years after a gestation period of 14 to 16 months. Sperm whales have a lifespan of 23 to 70 years, making them long-lived compared to pygmy and dwarf sperm whales.
Sperm whales are classified as a vulnerable species, while pygmy and dwarf species are not threatened. Research into their vocalizations has revealed a complex communication system, likened to a human phonetic alphabet, reflecting the richness of their social interactions and behaviors.
On this Page
Subject Terms
Sperm whale
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Physeteridae
Genus: Various (See below)
Species: Various (See below)
Some sperm whales can dive 560 feet (168 meters) per minute. When a sperm whale comes to the surface to breathe, the noise it makes can be heard half a mile away. Sperm whales can be found throughout the world's oceans, with the exception of the Arctic.
There are three different species of sperm whales in two genera. These species include the sperm whale, the pygmy sperm whale, and the dwarf sperm whale. They range in size. The male sperm whale has a head and tail length of about 52 feet (16 meters) and weighs around 45 tons (41 metric tons). Females are significantly smaller. The dwarf sperm whale grows to a head and body length of about nine feet (2 3/4 meters) and weighs only about 600 pounds (272 kilograms). The pygmy sperm whale grows to around 11 feet (3 1/2 meters) and weighs around 880 pounds (400 kilograms). Sperm whales have tail fins, small flippers, and some small bumps across their lower backs. They have very large square heads with long, narrow mouths on the bottoms of their bodies. They also have blowholes on the front tips of their heads. These mammals breathe through their blowhole. They have to go to the surface of the water to breathe. Each sperm whale has just one blowhole.
Sperm whales live in herds, depending on their age and sex. There are groups of females and young led by a dominant male. There are bachelor groups that include only young males, and there are adult males that live alone.
Sperm whales are carnivores, or meat-eating animals. Sperm whales eat cuttlefish, squid, and, sometimes, octopus. Large sperm whales often have scars on their heads from battles with giant squid. These squid try to protect themselves by smacking the whales with their sucker-covered tentacles. The suckers leave round wounds and scars on the heads of the whales. Given the larger size of the sperm whale, these battles usually end with the death of the giant squid and a meal for the sperm whale. Pygmy and dwarf sperm whales are also carnivorous but eat smaller prey.
Mating season for sperm whales takes place in the spring and the summer. The whales swim from cooler waters toward the equator to mate. The males develop harems, or groups of females, to mate with. The gestation period (duration of pregnancy) is between 14 and 16 months. The females then give birth to one calf, or young whale. Calves may nurse from their mother for two years or longer and females give birth every three to five years on average but may wait much longer if they are still caring for their calves. Pygmy sperm whales have the same mating season, but their gestation is only between 9 and 11 months and the females can give birth each year. Dwarf sperm whales may breed in the winter, but they have a similar gestation period to pygmy sperm whales.
The killer whale is the only predator of sperm whales. Large sharks may prey on the dwarf and pygmy sperm whales. Sperm whales have a life span of between 23 and 70 years, depending on the species. Sperm whales live much longer than dwarf or pygmy sperm whales. Sperm whales are a vulnerable species. Pygmy and dwarf sperm whales are not considered threatened species.
Scientists have studied the sounds sperm whales make for decades, trying to determine the meaning of their particular songs made up of different clicks. In 2024, new research revealed that the clicks that sperm whales produce are much more complex than previously thought. The scientists, who studied a group of sperm whales in the Caribbean, further determined that the whale sounds could be equated to a human phonetic alphabet.
Bibliography
Myers, Phil. “ADW: Physeteridae: Information.” Animal Diversity Web, animaldiversity.org/accounts/Physeteridae. Accessed 9 May 2024.
“Sperm Whale.” Australian Museum, 28 June 2022, australian.museum/learn/animals/mammals/sperm-whale. Accessed 9 May 2024.
Zimmer, Carl. "Scientists Find an 'Alphabet' in Whale Songs." The New York Times, 23 May 2024, www.nytimes.com/2024/05/07/science/whale-song-alphabet.html. Accessed 20 June 2024.