99 Fun Facts About Dolphins

What makes up the bulk of most dolphins' diet?

Fish and squid make up most dolphins' diet; pods herd fish into a tight 'bait ball' and take turns charging through it, while orcas also take seals and other marine mammals.

Which animal is scientifically classified as the largest species of dolphin?

The Killer whale, or orca, is roughly 200 times heavier than the smallest dolphin, and one of six Delphinidae species commonly called whales.

Which dolphin, the only cetacean endemic to New Zealand, is also among the smallest?

Hector's dolphin lives only in New Zealand waters; adults reach just 1.2–1.6 metres and about 50 kg, making it one of the smallest dolphins in the world.

Through what specialized opening do dolphins breathe air?

Dolphins breathe through a blowhole on top of the head, a modified nostril sealed by a muscular flap underwater; their exhaled spout is small and hard to spot compared with great whales'.

What is a typical group of dolphins called?

Where food is plentiful, pods merge into superpods that can top 1,000 animals; males are bulls, females cows and the young calves.

What sensory ability do dolphins use to navigate and hunt in low visibility?

Echolocation lets dolphins emit sound pulses and read the returning echoes, which reveal an object's position, size and shape even in murky or dark water.

Which fatty organ in a dolphin's forehead focuses its echolocation sounds into a beam?

The melon, a fat-filled organ in the forehead, focuses sound pulses made at the phonic lips into a forward beam; returning echoes are received through fat in the lower jaw.

Besides whistles, what sound do dolphins fire off in rapid 'trains' to echolocate, using nasal air sacs rather than vocal cords?

Clicks come from recycled air pushed through nasal air sacs and 'phonic lips', not vocal cords; a rapid directional series is called a click train.

A dolphin's conical teeth are built for what job?

They grab fish, squid and even seals; porpoises have spade-shaped teeth instead, the easiest way to tell the two apart.

How often can a bottlenose dolphin's outermost skin layer be replaced?

A bottlenose dolphin's outermost skin layer can be replaced every 2 hours, about nine times faster than human skin; the constant sloughing keeps the surface smooth and cuts drag.

Roughly how long is an orca's gestation period?

An orca's gestation lasts about 17 months, among the longest of any dolphin; a bottlenose dolphin carries its calf for about 12 months.

What is a dolphin's dorsal fin primarily composed of?

The dorsal fin contains no bone or cartilage; it is dense fibrous connective tissue, as are the tail flukes. Only the pectoral flippers hold bones, the remains of a land ancestor's forelimbs.

How do dolphins manage to sleep without drowning?

The waking hemisphere keeps them surfacing to breathe and watching for predators; a tail-kick reflex can also keep the blowhole above water.

Shark Bay bottlenose dolphins in Australia teach their young to wear what while foraging?

Shark Bay dolphins wear marine sponges on their beaks to protect them while rooting for fish on the seabed; the habit is learned, passed mostly from mother to daughter, a clear case of animal culture.

Which continent is home to the boto, a river dolphin with poor eyesight, thought to feel with hairs on its snout?

South America's boto, the Amazon river dolphin, is thought to use small hairs on its snout for touch; unlike sea dolphins, river dolphins have unfused neck bones and can turn their heads 90 degrees.

The word 'dolphin' comes from the Greek delphís, related to a Greek word meaning what?

The name can be read as 'a fish with a womb'; the 'ph' spelling was reintroduced through Old French daulphin.

How many extant species of dolphin are there?

About 40 extant species are called dolphins, spread across five families, from the 1.7-metre Māui dolphin to the orca, which can reach over 9 metres.

What are the closest living relatives of dolphins and other cetaceans?

Hippopotamuses are the cetaceans' closest living relatives: both descend from even-toed ungulates, and genetic studies group hippos and whales together as Whippomorpha.

Six dolphin species thought of as whales, including the orca, are known collectively as what?

'Blackfish' is the traditional name for six dark-coloured delphinids: the orca, false killer whale, pygmy killer whale, melon-headed whale and the two pilot whale species.

Unlike most other mammals, dolphin calves are usually born in what way?

Dolphin calves are born tail first, so the blowhole emerges last and the calf can be nudged to the surface for its first breath; most land mammals emerge head first.

What is the top speed an orca can reach in the water?

An orca can hit about 55.5 km/h (34.5 mph) in short bursts, making it one of the fastest marine mammals; fused neck vertebrae add stability at speed.

In Peru, dolphin meat is sold under the name chancho marino, meaning what?

Chancho marino means 'sea pork', the name under which dolphin meat is sold in Peru; although the hunt is illegal, fishermen harpoon thousands of dolphins a year.

Bottlenose dolphins are known to have 'signature' versions of what, unique to each individual?

Each bottlenose dolphin develops a signature whistle in its first year, a unique call used like a name; dolphins answer to their own whistles when these are played back to them.

Male river dolphins in Brazil have been observed using weeds and sticks for what purpose?

Male botos carry weeds, sticks and lumps of clay in their jaws and thrash them at the surface as a sexual display, behaviour seen far more often in adult males and in the presence of females.

How much does an average bottlenose dolphin weigh?

An average bottlenose dolphin weighs around 300 kg (660 lb), though adults range from about 150 to 650 kg; they can live for more than 40 years.

The baiji, a river dolphin declared functionally extinct in 2006, lived in which river?

The baiji lived only in China's Yangtze River, where fishermen called it the 'Goddess of the Yangtze'; a 2006 survey of the river failed to find a single animal.

The Amazon river dolphin, or boto, is famous for turning what colour as an adult, especially in males?

Adult botos turn pink, males most of all, a colour thought to come from repeated skin abrasion in fights; it is the largest river dolphin, with males reaching about 185 kg.

The 1960s TV series Flipper, about a dolphin and a park ranger's family, aired on which US network?

Flipper ran on NBC from 1964 to 1967 and was billed as an 'aquatic Lassie'; co-creator Ricou Browning had played the creature in Creature from the Black Lagoon.

Pelorus Jack, who escorted ships through New Zealand's French Pass from 1888, was what species?

Pelorus Jack was a Risso's dolphin, a blunt-headed grey species; after someone shot at him from a ship, the government protected him by Order in Council in 1904.

Which 1972 US law makes it illegal to harass, hunt or capture dolphins in American waters?

The Marine Mammal Protection Act of 1972 makes it illegal to harass, hunt, capture or kill dolphins in US waters without a permit; NOAA Fisheries enforces it for cetaceans.

Which orca ecotype of the northeast Pacific hunts seals, sea lions and porpoises rather than fish?

Transient (Bigg's) orcas of the northeast Pacific hunt marine mammals in small, quiet groups, unlike the fish-eating residents; the two ecotypes do not interbreed.

What is the term for a dolphin rising vertically to hold its head above the surface?

Spyhopping is a slow vertical rise that holds the head above the surface, letting a dolphin or whale look around; orcas spyhop to spot seals resting on ice floes.

In some coastal areas, bottlenose dolphins cooperate with local fishermen by doing what?

In Laguna, Brazil, bottlenose dolphins cooperate by driving fish into their nets: they herd mullet towards the shore and signal the moment to cast, then feed on fish that scatter as the nets fall.

Cetaceans split from the Indohyus, an extinct animal resembling what, around 48 million years ago?

Indohyus, a raoellid of about 48 million years ago, looked like a chevrotain, or mouse-deer, but had the thickened ear bone and dense limb bones that mark early whales and aquatic mammals.

Orcas flip great white sharks onto their backs to induce a paralysis called what?

Flipped upside down, a shark enters tonic immobility, a trance-like paralysis; orcas hold great whites inverted until they suffocate, eat the oil-rich liver and can empty an area of white sharks.

Which salmon species makes up most of the diet of northeast Pacific resident orcas?

Resident orcas of the northeast Pacific feed mainly on Chinook salmon, the largest and fattiest species, which makes up most of the southern residents' summer diet; other orca populations specialise in seals, sharks or rays.

Off Península Valdés in Argentina, orcas hunt sea lions using what risky technique?

Beaching is normally fatal to cetaceans and young orcas need years of practice to learn it.

Orca family groups are matrilines built around whom?

Orca matrilines centre on the eldest female: her sons and daughters, and her daughters' descendants, stay with her for life, and post-menopausal grandmothers lead the group to salmon.

What is it called when dolphins ride the pressure wave pushed ahead of a moving ship?

Bow-riding dolphins surf the pressure wave pushed ahead of a vessel's bow, gaining a free push; they do the same on the bow waves of large whales.

A 2014 study found which cetacean has more neocortical neurons than any mammal examined?

The long-finned pilot whale was found in 2014 to have about 37 billion neocortical neurons, roughly twice a human's; raw neuron counts, though, are not a simple measure of intelligence.

In Louis Herman's experiments, the bottlenose dolphin Akeakamai learned to understand what?

Akeakamai learned a human sign language of hand and arm gestures invented by Herman's team; her tank-mate Phoenix learned an acoustic version, and both understood sentences such as 'touch the frisbee with your tail'.

The Faroe Islands' drive hunt of pilot whales is mentioned in a law dating from which year?

The 'Sheep Letter' supplemented Norway's Gulating law; around 800 pilot whales are still taken annually.

What does the spinner dolphin do as it leaps from the water, earning its name?

A spinner dolphin leaps while rotating around its long axis, sometimes several times in one jump; the species lives in tropical and subtropical waters around the world.

The Amazon river dolphin was first scientifically described in 1817 by which French naturalist?

Henri de Blainville described Inia geoffrensis in 1817, giving it a species name honouring Geoffroy Saint-Hilaire; a 2002 DNA study suggested the Bolivian population is a separate lineage.

The two small rod-shaped pelvic bones in a modern dolphin skeleton are thought to be remnants of what?

The pelvic bones are remnants of the hind limbs of dolphins' land-dwelling ancestors; a bottlenose caught in Japan in 2006 had a small extra pair of fins on its underside, an unusually pronounced throwback.

Which god is often shown riding a dolphin in Roman art and later European painting?

Cupid riding a dolphin was a favourite Roman motif, seen on the Augustus of Prima Porta statue and in countless Renaissance paintings; ancient Greek coins likewise show boys and gods riding dolphins.

In Hindu mythology, the susu, a South Asian river dolphin, is linked to which deity?

Ganga, deity of the Ganges, is said to have had her descent heralded by the dolphin, and her mount, the Makara, is sometimes drawn as a dolphin.

Wild dolphins in the Port River of which Australian city have learned to 'tail-walk' across the water?

Adelaide's Port River dolphins learned tail-walking from Billie, a female who picked it up during a brief stay in a dolphinarium; the trick spread by imitation through two generations despite no survival benefit.

Which ancestral whale of 49 million years ago first routed sound from jaw to ear bone?

Ambulocetus, the 'walking whale' of about 49 million years ago, had an enlarged channel in its lower jaw that carried sound to the ear, as modern dolphins do; the earlier Pakicetus had a small, land-mammal jaw channel.

Which species is the most abundant cetacean on Earth, with roughly six million animals?

The common dolphin (Delphinus delphis) is the most abundant cetacean on Earth, with a population estimated at around six million; it is the only species in its genus, the type genus of the family Delphinidae.

The hourglass dolphin was accepted as a species in 1824 based solely on what?

Quoy and Gaimard named it from a drawing made in the South Pacific in 1820, making it the only cetacean widely accepted on eyewitness evidence alone.

Commerson's dolphin is nicknamed after which other black-and-white animal?

Commerson's dolphin is nicknamed the panda dolphin for its sharply divided black-and-white pattern, which has also earned it the names skunk dolphin and piebald dolphin; Philibert Commerson recorded it in the Strait of Magellan.

The critically endangered Māui dolphin survives only off the west coast of what?

A 2021 government report put the population at about 54 animals. The name comes from Te Ika-a-Māui, the Māori name for the North Island.

Which country has named the susu, a freshwater river dolphin, its National Aquatic Animal?

India declared the Ganges river dolphin, or susu, its National Aquatic Animal in 2009; it is also the city animal of Guwahati and is called shushuk in Bengali.

The Indus river dolphin was the first cetacean discovered to swim in what way?

The Indus river dolphin habitually swims on its side, trailing a flipper along the bottom to feel for prey in muddy water; in Pakistan its sub-populations are split by irrigation barrages on the Indus.

The franciscana, or La Plata dolphin, is the only river dolphin that lives where?

It is the only member of the Inioidea group found in the ocean and saltwater estuaries, off southeastern South America.

Despite living in Amazon rivers, the tucuxi belongs to which dolphin family?

The tucuxi is a true oceanic dolphin of the family Delphinidae, closer to the bottlenose than to the boto it shares the Amazon with; its name comes from the Tupi word tuchuchi-ana.

The Atlantic's Clymene dolphin was the first marine mammal confirmed to have arisen how?

The Clymene dolphin arose by hybrid speciation, from crosses between spinner and striped dolphins, the first such origin confirmed in a marine mammal (2014); older texts call it the short-snouted spinner dolphin.

The Irrawaddy dolphin takes its name from a river in which country?

The Irrawaddy dolphin is named for Myanmar's Irrawaddy River, though it also lives in the Mekong, Borneo's Mahakam and along coasts from India to the Philippines; its trick of spitting water makes it popular in Asian aquarium shows.

The melon-headed whale, a small blackfish, is also known as the 'what' dolphin?

The melon-headed whale, Peponocephala electra, is also called the Electra dolphin after its species name; other names include little killer whale and many-toothed blackfish. It is rarely seen at sea but gathers near islands such as Hawaii.

Winter, the bottlenose dolphin who inspired the film Dolphin Tale, was famous for having what, after a crab-trap injury?

Winter wore a prosthetic tail, fitted over a silicone gel sleeve developed by the Hanger Clinic, after losing her tail to a crab-trap line as a calf in 2005; she lived at the Clearwater Marine Aquarium until 2021.

In Dolphin Tale (2011), who plays the prosthetics designer who builds Winter's new tail?

Morgan Freeman plays Dr. Cameron McCarthy, the VA hospital prosthetics expert who designs Winter's tail; the film grossed about $96 million on a $37 million budget and got a sequel, Dolphin Tale 2, in 2014.

The Cove, about the Taiji dolphin hunt, hid its cameras inside fake versions of what?

The crew hid high-definition cameras inside fake rocks built by special-effects artists to film the hidden cove; director Louie Psihoyos shot it secretly in 2007 and it won the 2010 Academy Award for Best Documentary Feature.

The Japanese town of Taiji, site of the annual dolphin drive hunt, is in which prefecture?

Taiji lies on the Kii Peninsula in Wakayama Prefecture and has a whaling tradition dating to the 1600s; its drive hunt, run from September to March, featured in the 2009 documentary The Cove.

The voluntary global Dolphin Safe tuna standard is run by which Berkeley-based NGO?

Earth Island Institute's International Marine Mammal Project has run the voluntary Dolphin Safe standard since 1990; in the US the label also has legal force under the Dolphin Protection Consumer Information Act.

In marine engineering, what is a 'dolphin'?

In marine engineering a dolphin is a group of pilings used for mooring, driven into the seabed as a berthing point or a fender that protects docks and bridge piers from ships.

Lolita, also called Tokitae, was an orca displayed for over 50 years at which aquarium?

Lolita lived at the Miami Seaquarium from 1970, when she was captured from the southern resident population at Penn Cove, until her death from renal failure in August 2023, as plans were made to return her to the Salish Sea.

The US Navy Marine Mammal Program, whose dolphins hunt mines, is based in which city?

The Navy Marine Mammal Program is based at Point Loma in San Diego, training bottlenose dolphins and California sea lions to find mines and intruders; its teams deployed in the Vietnam and Iraq wars.

Which Greek musician was famously rescued by a dolphin after pirates forced him overboard?

Arion of Lesbos, a kitharode credited with inventing the dithyramb, was thrown overboard by his ship's crew and carried ashore at Taenarum by a dolphin; his patron was Periander, tyrant of Corinth.

Which title did the heir to the French throne hold from 1350 to 1791?

Dauphin, literally 'dolphin', was the heir's title after the lord of the Dauphiné of Viennois ceded his lands to the French crown in 1349 on condition the heir bore it; the Dauphin's crown had arches shaped like dolphins.

Ecco the Dolphin, the 1992 underwater adventure game, was published by which company?

Sega published Ecco the Dolphin for the Mega Drive/Genesis in 1992; it was created by Ed Annunziata at Sega and developed by the Hungarian studio Novotrade, later renamed Appaloosa Interactive.

How far may swimmers dolphin-kick underwater after a start or turn under World Aquatics rules?

World Aquatics (formerly FINA) limits the underwater phase after starts and turns to 15 metres in backstroke, butterfly and freestyle; the rule began in backstroke after 1988, when finalists kicked underwater for 30 metres or more.

A wholphin is a fertile hybrid between a bottlenose dolphin and which other species?

A wholphin is the offspring of a female bottlenose dolphin and a male false killer whale; Kekaimalu, born at Hawaii's Sea Life Park in 1985, has had calves of her own, and both parents are oceanic dolphins with 44 chromosomes.

Heaviside's dolphin is endemic to the Benguela ecosystem off the coast of which continent?

Heaviside's dolphin lives only in the cool Benguela Current waters off Namibia and South Africa, in Africa; it is one of four small Cephalorhynchus dolphins, alongside Hector's and Commerson's.

The black dolphin, Cephalorhynchus eutropia, is found only off the coast of which country?

The black or Chilean dolphin (Cephalorhynchus eutropia) lives only in Chile's coastal waters, from Valparaíso south to Cape Horn; it is one of four Cephalorhynchus species.

Fraser's dolphin was named in 1956 from a skull found in 1895 on a beach where?

Charles Hose found the skull on a beach in Sarawak, Borneo, in 1895 and gave it to the British Museum, where it sat unstudied until Francis Fraser described the species in 1956.

The genus name Steno, for the rough-toothed dolphin, comes from the Greek for what?

It refers to the animal's slender beak. Georges Cuvier first described the species in 1823.

Peale's dolphin, also called the black-chinned dolphin, lives around which place?

Peale's dolphin lives around Tierra del Fuego, the Falklands and the coasts of southern Chile and Argentina; 'Peale's dolphin' became the standard common name after Dale Rice's 1998 taxonomy.

Right whale dolphins of the genus Lissodelphis are distinctive for lacking what?

Right whale dolphins lack a dorsal fin entirely, a feature shared with the right whales they are named after; the northern species lives in the North Pacific, the southern in cool Southern Hemisphere waters.

Spinner dolphins rest in shallow bays by day and head offshore at night to do what?

Spinner dolphins head offshore for foraging at night, diving for lanternfish, squid and shrimp that rise toward the surface after dark; they spend the day resting and socialising in sheltered bays.

Atlantic spotted dolphin calves are born with how many spots?

Atlantic spotted dolphin calves are born with one or none — usually no spots at all; speckling begins around weaning at three to four years, then the pattern passes through speckled, mottled and fused phases with age.

Millions of pantropical spotted dolphins died in the 1960s-70s in which fishing gear?

Tuna purse seines set around dolphin schools killed millions of pantropical spotted dolphins in the eastern Pacific, where yellowfin swim beneath them; dolphin-safe methods and the 'backdown' release cut the toll sharply from the 1970s.

Lipotes, the genus name of the possibly extinct baiji, means what?

Lipotes means 'left behind' in Greek, and the species name vexillifer 'flag bearer'; Qi Qi, the last baiji known in captivity, died in 2002 and a 2006 survey found none in the wild.

The Amazon river dolphin eats up to 53 fish species, including which toothy one?

Botos eat piranhas among more than 50 fish species, along with river turtles, frogs and freshwater crabs, giving them one of the widest diets of any toothed whale.

Opo, the dolphin who played with children at Opononi in 1955-56, was what species?

Opo was a young female bottlenose dolphin who spent the summer of 1955-56 playing with swimmers at Opononi in the Hokianga; she was found dead in March 1956 and buried beside the town's war memorial hall with Māori honours.

Moko, a New Zealand bottlenose, won fame in 2008 for guiding which stranded animals free?

Moko guided two pygmy sperm whales, a mother and calf, past a sandbar at Mahia Beach in March 2008 after rescuers had failed for hours; she was found dead on Matakana Island in July 2010.

Hector's dolphin, which favours shallow coastal water around New Zealand's South Island, has a dorsal fin of what distinctive shape?

Rounded dorsal fins, grey, white and black colouring and a stocky body mark the species out; its lifespan is typically about 20 years.

The first commercial dolphinarium, Marine Studios, opened in 1938 in which US state?

It was in St. Augustine, and it was there that staff discovered dolphins could be trained to do tricks.

In which year was Free Willy, the film starring the orca Keiko, released?

Free Willy was released in 1993; its star, Keiko, was later moved from a Mexico City amusement park to Oregon and finally flown to Iceland, where he was released in 2002.

The bottlenose name truncatus refers to what feature of the original type specimen?

The specimen was simply old; worn teeth are not typical of the species. Tursio is Latin for dolphin.

Old Tom, an orca said to have helped whalers off Eden, Australia, was reportedly seen until?

Old Tom died in 1930, when his body washed up at Eden and his skeleton went to the town's killer whale museum; sightings reportedly began in the 1840s, though his teeth suggested an age of about 35.

Roughly how many teeth does Delphinus delphis carry, far more than a bottlenose?

A common dolphin carries roughly 188-268 small, sharp teeth, among the most of any dolphin; an orca has only 40-56 and a bottlenose 72-116, and captive common x bottlenose hybrids had intermediate counts.

Tião, the only bottlenose dolphin known to have killed a person, attacked in 1994 where?

Tião lived off Caraguatatuba on Brazil's São Paulo coast; after months of harassment, including people trying to push ice-cream sticks down his blowhole, he struck a swimmer who died of internal injuries in 1994.

A dolphin has featured in the coat of arms of which English town since at least 1563?

Poole's arms show a dolphin with three escallop shells; they were recorded at the heralds' visitation of 1563, and since a 1976 grant the dolphin has been drawn naturalistically rather than in stylised heraldic form.

Which Scottish firth holds the world's most northerly resident bottlenose dolphin population?

The Moray Firth's bottlenose dolphins, watched from Chanonry Point near Inverness, form the most northerly resident population of the species; they are larger and fatter than tropical bottlenoses.

The rosy colour of Chinese white dolphins comes not from pigment but from what?

Their pink comes from overdeveloped blood vessels just beneath the skin, which shed heat; adults of this Indo-Pacific humpback dolphin population lose the grey pigment of youth and live up to about 40 years.

Which southern dolphin's leaps are classed as noisy, clean, acrobatic and coordinated?

Dusky dolphins are famed acrobats whose leaps are grouped as noisy, clean, acrobatic and coordinated; calves learn the styles in that order, finishing with acrobatic somersaults.

Striped dolphins in the eastern Pacific are nicknamed what for fleeing from vessels?

Eastern Pacific striped dolphins earned the nickname 'streakers' from researchers for racing away from ships; in the Atlantic and Mediterranean they readily approach boats, and past hunting pressure in the Pacific may explain the difference.

What is the term for dolphins travelling fast in a series of long, low leaps?

Porpoising is fast travel in a series of long, low arcs clear of the water; leaping cuts drag compared with swimming at the surface, so it saves energy at speed.