Oceans of the world provide an aquatic area for a myriad of wildlife species – about 90 species of whales, porpoises, and dolphins— some of which are seen swimming along the coasts.
Thus far, only 3 percent of the world’s ocean is protected from mining and drilling.
- Scientific name: Physeter macrocephalus
- Group name: Pod
- Type: Mammals
- Diet: Carnivore
- Size: 49 to 59 feet (adult)
- Weight: 35 to 45 tons (adult)
Whales are a species of fully aquatic mammals of the Cetacea. Whales consist of two parvorders, which are the baleen whales (Mysticeti) and the toothed whales (Odontoceti).
The Sperm whale, which is also known as Cachalot (Physeter macrocephalus), is the largest toothed whale and the largest toothed predator.
The sperm whale got their name from the spermaceti or sperm oil, as they may be likely called found on their head. It’s still a mysterious substance to date, although most scientists argue it to be sperm, it is not widely acknowledged.
The sperm whale is the creature that possesses the largest brain on earth; it is five times heavier than that of a human.
Also, sperm whales are the third deepest diving mammals surpassed only by the Curvier’s beaked whale and the Southern elephant seal. Their huge square head and narrow lower jaw make them easily identifiable.
They are carnivores with an estimated weight of 35 to 45 tons, and they grow to an estimated size of 49 to 59 feet. The sperm whales live in the open sea, and they migrate seasonally for feeding and breeding.
The adult male sperm whale, which is known as “Bull” live solitarily except for the mating season while the female and younger males live together in groups.
The average breeding period for a female sperm whale is 4 to 20 years, and they take care of their offspring (calves) for over a decade. The head of a sperm whale is filled with spermaceti, a mysterious substance usually termed as sperm oil.
Life cycle of the Sperm Whale
Sperm whales have been known to live 70 years or more. Their reproductive strategy has to do with very stable environmental conditions, strong parental aid to offsprings, low birth rate, slow growth, and high longevity.
The males fight over females and mate with multiple females, but they do not provide paternal care to offsprings.
The males become sexually mature at 10 years or more of age and move to a higher latitude for a colder environment and more productive feeding. At the same time, females reach sexual maturity at about 7- 13 years of age, and they give birth every 4 to 20 years.
During the birth process, mother and calf need protection from predators, thus giving birth for sperm whales tend to occur as a social event.
Sperm whales are known to prefer deep and ice-free waters, so their population is distributed from the poles to the equator and are present in all the oceans. They also live in the Mediterranean but haven’t been cited in the Black Sea, while it is uncertain if they inhabit the Red Sea.
It is speculated that the shallow entrances to the Red Sea and the Black Sea may be the cause of their absence. The sperm whale population is known to be denser close to continental shelves and canyons.
While they are usually found in deep, off-shore waters, sperm whales may be seen closer to shore in areas where there are small continental shelves that drop quickly to depths of 310 to 920 meters (1,020, to 3020 ft).
Sperm whales are known to be able to dive as deep as 3,280 feet in search of squid their favorite meal. A common theory proposed is that the spermaceti, which hardens to wax when cold, allows the whale to adjust its buoyancy so it can dive deep and rise again.
Behaviors of sperm whales
While the males (bulls) tend to live alone, the females and calves move in groups, usually called pods that mostly consist of 15 to 20 sperm whales.
Immediate, mature males of the same age group sometimes form loose bachelor groups but live solitary lives as they grow older. The known reason for males living solitary life is because of competition for squids.
Sperm whales barely socialize, as they spend most of their time foraging, but when they do socialize, it is done at noon, and they do this by complex emitting patterns of clicks usually called Codas.
In this process, they spend most of their time rubbing against each other. Their highly developed echolocation ability aids navigation and is used to locate food.
Relationship to humans
The relationship between sperm whales and humans can be generally termed as SPERM WHALING.
Sperm whaling is a process where humans hunt the sperm whales for their sperm oil (usually gotten from the blubber in their body) or spermaceti (usually obtained from the spermaceti organ).
Spermaceti (sperm oil), which the name of the whale was derived from, was the main objective of the whaling industry and was highly sought after. There is a fluid-filled organ that whalers called the “case” in the head of the sperm whale.
Spermaceti was highly valued by the whalers because it could be cooled into wax and used in making ointments, industrial lubricants, cosmetic creams, textile finishing products, salves, and fine wax candles.
There is also the presence of ambergris, a solid waxy waste product in the digestive system of the sperm whale. It is also of high value, and it is used as a fixative in perfumes amongst other uses.
The whale’s spermaceti organ holds the sperm oil, a pale yellow oil used as lighting oil, and as a lubricant in the manufacturing of soap.
Sperm whale oils were being used as primary energy or lighting source In the U.S and Europe, as at that time, sperm whale oil had the highest quality and volume per whale.
During the harvest of whales, the spermaceti organ was discovered to hold a white liquid, which the whalers mistook for the sperm of the whale.
After one hundred and fifty years of commercial whaling, the population of sperm whales was slashed in half, and scientists estimated that the population was reduced by 75%. Whaling ceased to exist in the year 1988.
Still, the recovery of the sperm whales from this practice can’t be ascertained as marine biologists still consider them vulnerable to extinction as they are still subjected to other threats, including; Chemical water pollution, entanglement in fishing gears and noise pollution.
The international whaling commission moratorium protects these species, and they are also listed as vulnerable by The International Union Conservation Of Nature. Sperm whales, however, are still the most common large whales on the earth.
Relationship with other species
Sperm whales may be large and mighty, but they are also subjected to predators from the other whale species, such as the Killer whales and the pilot whales.
The killer whale is known to be the most natural predator of the sperm whale; they tend to attack a group of females with calves, having the intention of separating and feasting on a calf.
The adult sperm whales have two kinds of defensive position for this attack, and they are;
- The Marguerite formation. It is performed by the adults circling an injured female or the calf. They do this facing inward, leaving their tails outward to deliver heavy blows to their predators. This can be seen as both an offensive and defensive position.
- The heads out formation. on the other hand, it is just the exact opposite of the Marguerite formation. In this formation, they encircle the calf or injured adult female with their head facing outward. This can be seen as a purely defensive position.
Predatory nature of the sperm whale
The sperm whales are predators that prey on giant squids, bony fishes, and sharks. They possess unique physical attributes that aid them in this predatory act.
Some of these attributes are;
- Large conical teeth for trapping their prey.
- They have the most powerful sonar, which they use to track their prey in the dark sea.
- Their ability to dive an unimaginable depth of 1000 meters and remain there for close to 2 hours.
- And finally, they have large brains, which make them very active predators.
Amazing facts about the sperm whale
- Sperm whales are the largest of the toothed whales. Males weigh up to 50 tons, which is more than 700 people put together. Their head is about one- third of their body length, and they have the largest brain than any animal on earth
- The Marine Mammal Protection Act and the Endangered Species Act protect sperm whales from being harassed or hunted and killed in domestic waters.
- Deep-sea oil and gas exploration poses a lot of health risks for sperm whales such as loss of hearing, increased risk of being hit by ocean vessels, and water pollution from hydrocarbons.
- Sperm whales can dive to a depth of more than 3,000ft. They mostly dive this deep to hunt for prey like squids. Sperm whales can also hold their breath for up to 90 minutes.
- Sperm whales are constantly feeding. They can eat up to three percent of their body weight every day, sometimes up to two tons of food