Sperm whales are the largest toothed whales in existence, with mature males averaging 15 to 16 meters long and weighing more than 40 tons, while females weigh an average of 11 meters and 14 tons. The largest sperm whale on record is over 20 meters long and weighs more than 90 tons.
The sperm whale, the largest toothed whale, sits firmly, and the second largest toothed whale, the Brinell's beaked whale, has a maximum body length of only 12.8 meters. Nevertheless, sperm whales also have natural enemies, and their natural enemies are killer whales. Pilot whales and pseudo-killer whales have also been recorded attacking or harassing sperm whales, but they are not natural enemies. So why do sperm whales grow so big but can't fight killer whales?
sperm whale
Body size comparison
Killer whales are the largest toothed whales in addition to sperm whales and several beaked whales, and are also the largest dolphins (killer whales are of the toothed whale suborder Dolphin family), taking the Antarctic Type A killer whale as an example, the male whale averages 7.3 meters long and weighs about 5 tons, and the female whale is 6.4 meters long and weighs 3.5 tons. The largest scientific expedition record for killer whales was 9 meters and 11.6 tons, and the maximum hunting record was 9.45 meters and 13.4 tons.
Mature sperm whales are indeed very large, but when they first reach adulthood, male whales are only 10 to 11 meters long and weigh 11 to 12 tons, and female whales are 8 to 9 meters long and weigh 6 tons, and the body size advantage of killer whales is not large, especially female whales. Large male killer whales are likely to be larger than smaller adult female sperm whales.
killer whale
Hardware and software analysis
Although sperm whales are toothed whales, their teeth have been severely degraded due to long-term specialized predation of cephalopods. Only a few stumped teeth remain in the upper jaw, which are not functional. The lower jaw is disproportionately narrow, with 18-26 lower teeth on each side, which can be inserted into the fossa of the upper jaw. The jaw is less strongly connected to the skull, so the jaw is flexible enough to bite some of the larger targets.
The sperm whale is widely known for hunting the king squid, but in fact, its staple food is medium-sized squid. In the waters off the Galapagos Islands, sperm whales prey on squid weigh between 12-650 grams. The most gold-rich of the prey that sperm whales have killed is the megalobial shark, a filter-feeding shark with a body length of more than 6 meters, which is not a regular prey for sperm whales, and one unlucky guy was bitten to death by the sperm whale. However, this at least proves that the mouth of the sperm whale still retains a certain lethal ability.
Compared to sperm whales, killer whales have much better teeth, their mouth is full of tapered fangs, their upper and lower teeth can bite normally, and their jaws are very strong. So, while killer whales are smaller than sperm whales, they are more capable of fighting.
Stranded sperm whale, showing its disproportionately narrow jaw
What makes a killer whale better than a sperm whale is its temperament. Sperm whales are already less aggressive against other marine animals due to their specialized squid- diet, while killer whales, which are today's ocean overlords, are aggressive. Different types of killer whales are adapted to hunt different prey, their prey includes a variety of fish, cetaceans and pinnipeds, the largest baleen whale blue whale, fin whale, etc. are on their menu, and sperm whales are certainly no exception. Therefore, when killer whales and sperm whales encounter, one wants to kill each other, and the other only wants to protect themselves, the sperm whale loses in momentum.
Sperm whales and killer whales are both active in groups, their groups are matrilineal groups, composed of mothers and offspring, the group size is mostly less than 10, but the upper limit of the killer whale group seems to be higher, with a large group of more than 30, and the large group of sperm whales is about 20 or so.
In terms of social structure, there is a big difference between the two, that is, the adult male killer whale never leaves its mother for life and continues to stay in the birth group. Male sperm whales are separated from the group at the age of 4-21, young male whales form a bachelor's alliance, and old male whales live a lonely life.
Killer whales with full mouths of fangs
Examples of predation
Killer whale swarms attack sperm whale swarms target juvenile whales, and sperm whales form a "rose array" to confront them, that is, adult female sperm whales face inward and tail outwards, surrounding young individuals in the middle, flapping powerful tails, deterring killer whales, so that they dare not attack closely. However, the rose array's defensive effect is not ideal, and because the baby sperm whales are too weak, killer whales usually find opportunities to kill one or more.
Killer whales have endurance and speed, and are an all-round hunter. It can swim at speeds of up to 45 km/h and also 20 km/h when cruising. The sperm whale has a large head and a small body shape, which is not good for swimming, and the swimming speed is only 37 kilometers. Therefore, when a sperm whale encounters a killer whale, there is no way to escape by swimming.
Sperm whales are strong divers, can dive up to 2000 meters deep sea, while killer whale diving ability is very weak, mostly within 100 meters below the sea surface, deep diving seems to be a good way for sperm whales to escape the killer whale pursuit. However, although the sperm whale has excellent diving ability, the preparation before the deep dive is indispensable, and it is impossible to dive immediately in a hurry when encountering the killer whale, so it is still mainly gathered in situ. Coupled with the fact that juvenile sperm whales are not yet able to dive, female whales can only stay on the surface of the water to circumvent killer whales in order to protect juvenile whales.
Sperm whale females and juveniles
When the killer whale swarm is too large, adult female sperm whales can also be killed by killer whales, and in one extreme case, one sperm whale swarm is almost extinct. In 1997, in an attack in California, 35 killer whales attacked 9 sperm whales (only one juvenile whale, the rest were adult, sub-adult), the result was that the largest female sperm whale was killed, most members of the sperm whale swarm were injured, several of them were seriously injured, researchers speculate that at least 3 to 4 survivors will eventually die of injuries.
When the sperm whale herd is besieged by killer whales, the nearby male sperm whales will also come to support, not limited to "babies and fathers". This is an act of altruism, and as long as all male whales insist on doing so, it is good for its own offspring and the entire sperm whale population. Sometimes, the support of male sperm whales can wear away the patience of killer whales as soon as possible, so that killer whales can spare sperm whales. Sometimes, the presence of male sperm whales does not stop killer whales from killing.
Killer whales attack sperm whales
Because both attack power and flexibility are inferior to opponents, sperm whales have the advantage of body size, but they can't do killer whales, and often need a relatively large numerical advantage to protect the juvenile whales. Once, 8 killer whales attacked the sperm whale herd, and more than 30 male sperm whales rushed to the rescue, and the large male whales blocked in front of the killer whales and tried to cover the escape of the female sperm whales and cubs, and changed three formations successively. Eventually, the sperm whale used the boat as a bunker to repel the killer whale.
Adult male sperm whales have a large advantage in size, coupled with significantly stronger attack power than females, in the face of killer whales to protect themselves, so far there is no record of killer whales killing adult male sperm whales.
Groups of killer whales sometimes rob male sperm whales of food. Once, two female killer whales tried to rob an adult male sperm whale, but without success. Another time, the sperm whale killed a 300-kilogram king squid in the deep sea, and when it was brought to the sea to be enjoyed, it was snatched away by 6 killer whales, and the sperm whales that had just completed the deep dive were exhausted and had to consider themselves unlucky.
Studies have shown that when killer whales are heard, even adult male sperm whales acting alone will show uneasiness, and even prompt them to form alliances to defend against predators. It can be seen that even male sperm whales are afraid of killer whales.
In the animal world, although usually whoever is bigger is stronger, body size is not the only decisive factor, and the advantages of killer whales in aggression and aggressiveness make up for the lack of small size. Although sperm whales are larger toothed whales than killer whales, they can only be preyed by killer whales.
Restoration of Leviathan whales on The Mech
Sperm whales have been in severe decline today, with only three species of sperm whales, baby sperm whales and pygmy sperm whales remaining. Some prehistoric sperm whales were highly predatory, such as the Leviathan whale, which is more than 17 meters long, weighs an estimated 50 tons, and has a mouth full of sharp teeth, making it one of the strongest marine predators ever. If it can be revived, dozens of killer whales are not opponents, and the position of ocean overlord will be replaced.
Source of this article: Zoology, invasion and deletion