Wolves of the Sea

Orcas, also known as “wolves of the sea,” or “killer whales,” belong to the oceanic dolphin family. Ancient sailors gave them their nickname after watching orcas hunt whales. Though orcas are an apex predator, they’re also an emotionally-intelligent mammal with strong social bonds that last a lifetime. Baby orcas gestate for 15-18 months, and it’s not uncommon for a mother orca to nurse her offspring for two years. Baby whales are called calves, and they have a lot to learn from their pod. Scientists speculate that orcas and other cetacean species are also able to experience complex emotions like love.

Older orcas fill the important role of teaching younger pod members how to hunt with sonar, what to eat, and how to communicate. These family groups have their own unique culture that is passed down. In fact, killer whales are found in every ocean, and even have their own regional dialects, or accents. There are different kinds of orcas, too, all with their own distinct dietary preferences, and genetic differences.

One surprising difference between us and orcas is that they have to consciously choose to breathe even when they’re sleeping! They really do sleep with one eye open. Their specialized sleep is called unihemispheric sleep, where only one brain hemisphere is unconscious at a time.

The Smallest Whale

The smallest whale in the world is the dwarf sperm whale. This fun-sized species is even smaller than some dolphins! On average, it weighs 400 pounds, and reaches a length of about 7 feet. Dwarf sperm whales are suction feeders that can be found in temperate and tropical oceans. They primarily feed on squid and can release a cloud of dark fluid when they’re scared.

The Largest Whale

Baleen Whales and Toothed Whales

All species of whale are either baleen whales, or toothed whales. The easiest way to tell them apart is by how they feed. Baleen whales have baleen plates in their mouths that help them filter fish, zooplankton, and small crustaceans called krill from the water. Unlike toothed whales, baleen whales don’t use echolocation for hunting. 

There are more species of toothed whales, and they use echolocation to hunt for fish, seals, squid, and other marine animals. Orcas have even been known to hunt great white sharks!

Dolphins Have Many Homes

There are 4 species of freshwater river dolphin that are only found in the Amazon, but most dolphins live in the ocean. Altogether, there are about 40 species. Dolphins are highly adaptable and survive in water that ranges widely in temperature.

Did you know that dolphins have 2 stomachs, but they don’t chew their food? They can also dive up to a thousand feet underwater, which is much deeper than even an Olympic swimmer can dive. Some scientists even think that dolphins name themselves and respond to their own unique whistle.

How Fast Can You Swim?

Dolphins usually travel at a relaxed pace, but they can reach speeds of up to 35 mph when they’re really on the move. For reference, the average human swims at a rate of about 2 mph, but even Michael Phelps only clocks in at 6 mph. The short-beaked common dolphin tops out at 37 mph, which is just slightly faster than a hungry orca. Larger marine mammals, like blue whales, prefer to cruise along at a more leisurely pace when they’re feeding about 5 mph.

Some Whales “Sing”

Some species, like humpback whales, fin whales, and blue whales, are known to communicate through underwater songs. While both males and females are able to vocalize social calls, males create complex melodies that carry for miles. Scientists still have a lot to learn about whale songs. 

Whistles, Clicks, and Chirps

Did you know that sound travels faster through water? Dolphins use echolocation to hunt prey, but they also make a lot of other noises, like whistles and clicks. In fact, they have a diverse range of acoustic options. Simply put, echolocation is reflected sound. Through these sound waves, dolphins can tell the size, shape, and speed of objects in the ocean. There are other animals that rely on echolocation, too, and they don’t all live underwater. Bats are another type of mammal that hunts primarily by sound. 

Feast or Famine for Humpback Whales

Another interesting fact about humpback whales is that they don’t need to eat all year long. They migrate like some species of bird and are able to live off of their fat reserves for several months at a time.

Smart Like a Dolphin

Bottlenose dolphins are one of the few clever species able to recognize themselves in a mirror. Dolphins have also been seen using marine sponges as tools to protect their beaks from sharp rocks. The use of tools is widely accepted as a sign of intelligence.

Incredibly, an orca’s brain can weigh up to 15 pounds, so it’s easy to see why they’re one of the most intelligent animals. In fact, orcas have the second largest brain, which helps them form social networks with deep emotional bonds

A Tusk is a Tooth

When you think of animals with tusks, you probably think of an elephant. But male narwhals have a single tusk that may be used to display dominance toward other males, or even help them break through ice. Narwhals are found in Arctic waters, and winter for several months beneath the sea ice in the Baffin Bay-Davis Strait. Their tusk can grow to be 9 feet long, weighing over 20 pounds. That’s one big tooth!

Whales and Dolphins Blow Bubbles

Some species of whales and dolphins blow bubbles to round up their prey. This is called bubble net feeding. Fish will not cross through the bubbles. Dolphins will also slap fish with their tails to stun them. A stunned fish is easier to catch. When a dolphin does catch a fish, they prefer to swallow them headfirst. This is thought to prevent fish scales or spines from getting lodged in the soft tissue of their throat.

The Longest-Living Mammal

Whales can live for a long time. Not only are they the largest mammals on Earth, but whales are also the most timeless. Bowhead whales, for example, can live for over 200 years. One orca, given the name “Granny,” was first observed in 1976. Scientists from the Center for Whale Research estimate that Granny was over 100 years old by the time she went missing from Puget Sound in 2016. Female orcas are known to naturally have a longer lifespan than male orcas.

Whales and Dolphins Love to Mingle

Some whales and dolphins are more solitary, but many species tend to be social animals that travel and hunt together in groups. These groups are called pods. Sometimes bottlenose dolphin pods briefly gather to create a “superpod.” These superpods can bring more than 1,000 dolphins together at one time!