Whales, Dolphins, Interesting Facts
Whales and dolphins are fascinating creatures. Their unique abilities and perfect adaptation to the marine environment continue to amaze us. Which whale dives the deepest? What is a fin? How do whales see underwater? Do whales and dolphins drink water? These and other questions are answered here.
Source: WDC
Whales and Dolphins Are Mammals
• They breathe with lungs: they take in oxygen from the air and must come to the surface to breathe regularly.
• They maintain a consistently high body temperature.
• Whales and dolphins give birth to live young and nurse them with milk in the first months of life.
Did you know…?
• Sperm whales can dive as deep as three kilometers. There, they hunt deep-sea squid. For humans, it would be impossible to dive so deep in a short amount of time or return to the surface quickly due to pressure differences.
• Narwhals have a tusk that can be up to three meters long. Researchers have observed them using it to stun fish with a powerful strike before consuming them. The tusk can also help narwhals “measure” temperature or salinity in their environment.
• Fin whales are the second-largest mammals on Earth and are also incredibly fast—up to 45 kilometers per hour! Additionally, their calls can reach up to 188 decibels, louder than a jumbo jet. However, humans cannot hear these sounds in this frequency range. Fellow whales, however, can hear these calls up to 850 kilometers away. The oldest known fin whale lived to 111 years old.
• Botos, also called “Amazon river dolphins,” do not live in the sea but in freshwater. The Ganges dolphin in India is also a freshwater dolphin. Their existence in river systems makes them particularly vulnerable to droughts, water pollution, and food shortages.
• Porpoises are the only whale species native to German waters. These agile hunters catch up to 500 fish per hour with a 90% success rate!
How to Tell Whales and Dolphins Apart?
Currently, over 90 species are known, divided into baleen whales and toothed whales.
Baleen whales include most of the large whales, except the sperm whale. They feed on krill, plankton, and small fish, filtering them from the water using their baleen plates. They can be recognized by their two blowholes, which create a V-shaped spout.
Toothed whales include all dolphin species, porpoises, beaked whales, and the sperm whale. They have teeth and hunt larger prey such as seals, other smaller whales or dolphins, larger fish, squid, or rays. They have only one blowhole and produce an I-shaped spout.
Fluke, Flipper, and Fin
The pectoral fins are used for steering, and the dorsal fin (when present) provides stability while swimming. The tail fin (or fluke) is used for propulsion. Large whales often lift their flukes out of the water when diving. This is not only a beautiful sight but also allows for the identification of individual whales based on the unique patterns on their tail flukes.
Many documented cases show whales and dolphins missing a fin, either completely or partially. They may have become entangled in fishing gear, been injured by ship propellers, or barely escaped a fight. In some cases, such individuals can still lead normal lives.
How Do Whales and Dolphins Sleep?
In documentaries, you might see sperm whales floating motionless in the water, vertical while sleeping. How whales and dolphins sleep underwater is a mystery to many, as they, like other mammals, need to breathe regularly. Additionally, the ocean holds many dangers that whales and dolphins must avoid.
Do Whales and Dolphins Have Hair?
All mammals have hair, and whales and dolphins are no exception. However, evolution has resulted in extremely smooth skin, with almost all hair lost. Most species have a few tiny hairs at the tip of their snout, which they lose before or shortly after birth.
An exception is the Amazon river dolphin (Boto), which retains these hairs throughout its life. It is believed that these hairs, in addition to echolocation, help river dolphins find prey in the murky riverbeds.
Some baleen whales also have individual hairs on their heads. Humpback whales have them on the “tubercles,” the small bumps on their heads. These hairs are similar to the whiskers of cats and serve sensory purposes.
How Do Whale or Dolphin Babies Nurse?
Mother whales and dolphins must nurse their babies underwater and while swimming. Their nipples are hidden in skin folds, so the newborns cannot simply suckle. Instead, the milk is squirted into the baby’s mouth under pressure, ensuring that no fat- and nutrient-rich milk is lost.
A blue whale baby drinks hundreds of liters of milk per day!
Are There White Whales and Dolphins?
Just like humans, whales and dolphins can have genetic traits that result in white skin (in species that are not typically white). This condition is known as leucism or albinism. Leucism results in few pigments being produced, while albinism involves a complete absence of pigment-forming cells. Albino whales and dolphins are often slightly pink rather than white. Leucistic whales and dolphins may have some pigmented areas.
White whales and dolphins stand out visually from their peers. Some individuals are even famous, such as the Russian orca Iceberg or the humpback whale Migaloo. Migaloo was first sighted in 1991 off the coast of Australia—at the time, he was the only known white whale in the world. Later, more white whales were spotted, including white porpoises discovered in the Baltic Sea in 2013 and 2015. They are extremely rare, with only about 15 white individuals of this species documented in the past 100 years.
White skin is especially vulnerable to sunburn, as it lacks the pigments that normally provide protection against UV radiation. It might be assumed that white whales have a harder time surviving, as they could be more easily spotted by predators. However, there is no scientific evidence to support this claim.
All Belugas Are White!
At birth, a beluga calf is dark gray, but as it matures, its skin becomes lighter. Between the ages of five and twelve, belugas undergo a color change to pure white, which helps them blend into their natural icy habitat.
How Do Whales and Dolphins Communicate?
Whales and dolphins communicate in various ways: through sounds, physical contact, and body language. Large whales can communicate over vast distances using low frequencies. Toothed whales, on the other hand, use higher frequencies (ultrasound), which limits the range of their communication.
Dolphins communicate with two types of sounds: whistles and clicks. The clicks are used for echolocation, to explore their surroundings, navigate, and hunt, while the whistles are more for communication with other dolphins (and possibly other species). Some species have unique signature whistles that identify them individually. Dolphins can apparently “call each other by name,” which is unique in the animal kingdom!
How Do Whales and Dolphins See and Hear Underwater?
Dolphins have excellent vision (except for river dolphins), both underwater and above water. Toothed whales also use echolocation to navigate and hunt. They emit sound waves that bounce off objects, creating an accurate picture of their surroundings, even more precise than any sonar device developed by humans.
Marine mammals do not have external ears (pinnae). Instead, they receive sound waves through their jawbones, from where the sound is transmitted to the inner ear. They also lack noses and olfactory nerves, so it is assumed they do not have a sense of smell. However, they have an excellent sense of taste and can “taste” the seawater with their tongues, preferring certain types of fish or marine creatures.
