There are few marine wildlife displays above the water that rival the spectacular leaps and rapid spinning twists of the spinner dolphin, say the experts at Whale and Dolphin Conservation. The clue is in the name, right? These small, energetic dolphins are ocean acrobats.
Their aerial antics can include multiple spins during a single jump, leaving those fortunate enough to see these moves awestruck by their agility, grace and sheer exuberance. Spinner dolphins are also intelligent and highly social, and play an important role in the marine ecosystem.
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Where do spinner dolphins live?
Spinner dolphins live in all tropical and most subtropical waters around the world across the Atlantic, Pacific and Indian oceans. The most common subspecies is called Gray’s (or Hawaiian) spinner and is found throughout the spinner’s tropical and subtropical range – except in parts of tropical Asia and Eastern Tropical Pacific (ETP).
The Eastern spinner occurs in the ETP off the coasts of South and Central America; the Central American spinner is found only in a narrow strip of habitat along the west coast of Central America; and the Dwarf spinner is found only in Southeast Asia and northern Australia. There is also a large population of white-bellied spinner dolphins, which are a hybrid form of Gray’s and Eastern spinners.
How and why do they spin?
Many dolphins may occasionally spin when leaping from the water but only with a couple of revolutions, but the spinner has been recorded fully spinning along their longitudinal axis up to seven times during a single leap.
The spinner starts to spin in the water just before emerging head first and leaping up to 3m into the air, rotating continuously before falling back into the sea on their side with a huge splash. As a result, they are a firm favourite with dolphin watchers. Intriguingly, we don’t know for certain why they spin like this.
It is likely that this has some sort of social function as an acoustic signal or communication, and to remove ectoparasites such as remoras (suckerfish). Their favourite spinning time is in the late afternoon and early evening after they have rested and are preparing to head off to hunt.
Do they come to the surface for long?
Spinner dolphins usually surface only briefly to inhale before diving again. Most dives last a few minutes, although they can remain underwater longer when searching for food.
What do spinner dolphins look like?
All spinner dolphins have a long, slim beak, a slender body, small curved flippers with pointed tips and a tall triangular dorsal fin. Large males in the ETP often have a rather unusual forward-sloping ‘back-to-front’ dorsal fin.
Most spinner dolphins have a distinctive three-tone colour pattern: dark grey on the back, lighter grey along the sides and white or pale grey underneath, with a dark band from the eye to flipper and a thin pale line above. But the exact colouring can vary depending on the population and geographic region. Other spinner dolphins are dark grey all over.
How big are spinner dolphins?
Spineer dolphins are around 5 metres long and can weigh up to 90kg
Do spinner dolphins have teeth?
Yes. Spinner dolphins possess between 45–65 pairs of sharp, cone-shaped teeth in each jaw. These teeth are primarily used for gripping slippery prey rather than chewing.
What do spinner dolphins eat?
Spinner dolphins have quite a varied diet, eating small fish, shrimps and squid. Many of their prey species live in deep water and migrate closer to the surface at night.
How do they track their prey?
Like all toothed whales and dolphins, spinners use echolocation. They produce high-frequency clicks that bounce off objects and return as echoes. This biological sonar allows them to locate prey, navigate and detect obstacles – even in dark or murky water.
How fast can spinner dolphins swim?
Spinner dolphins’ streamlined bodies are ideal for travelling at rapid speeds. They can reach approximately 25–35 kilometres per hour (15–22 miles per hour).
Are they intelligent?
Yes. Like other members of the dolphin family, spinner dolphins possess relatively large, complex brains and display behaviours associated with high intelligence, including cooperation, problem-solving, social learning and communication. Their frequent spinning routines could well be just for fun and play behaviour is another sign of intelligence.
Do they interact with other species of whale or dolphin?
Spinner dolphins are often observed associating with other dolphin species, including spotted dolphins and bottlenose dolphins. They may also be seen near larger whales while feeding.
How long will the calf stay with his or her mother?
A mother may nurse a calf for up to two years and young often remain close with mum for several years while learning essential social and survival skills.
What sounds do they make to communicate?
Spinner dolphins produce a wide variety of sounds to communicate and navigate, including clicks, whistles and pulse-like sounds.
Do they form pods or super pods?
Spinner dolphin pods range in size from fewer than fifty to thousands. Their social structure varies considerably amongst the different subspecies. Some populations have fluid arrangements where dolphin groups join up and separate from time to time. Others live in stable pods for many years.
How long do spinner dolphins live?
Spinner dolphins typically live between 20–30 years, although some individuals may survive into their late 30s.
Do they have natural predators?
Spinners must remain vigilant for natural predators like large sharks and orca. Young calves are particularly vulnerable and may be targeted by larger predatory fish.
How do they protect themselves?
Spinners often rely on ‘the group’ for protection. Pod members remain vigilant and may bunch together when predators are nearby. Their speed, agility and coordinated movements can help them evade attacks.
What are the main threats to spinner dolphins?
Specific populations face threats from accidental capture in fishing nets and gear (known as bycatch). Boat traffic, pollution and disturbance from commercial dolphin watching operations and recreational activities also threaten these dolphins.
Are they endangered?
Spinner dolphins are currently classified globally as Least Concern by the International Union for Conservation of Nature (IUCN). However, some regional populations face significant pressures, including from the tuna fishing industry in particular, which has led to the ETP eastern spinner dolphin subspecies being categorised as Vulnerable.
From tropical coastlines to vast offshore waters, spinner dolphins continue to delight scientists, sailors, and wildlife enthusiasts alike. Their remarkable spinning leaps, strong social bonds and intelligence make them one of the most fascinating marine mammals on Earth. But only they really know why they spin.
Critically, new research in recent years, has highlighted the species’ importance in acting as nutrient vectors, particularly in coral reef ecosystems, as they rest and forage inshore during the day and forage offshore at night, this is referred to as the dolphin tap (supporting the health and resilience of coral reefs by providing essential nutrients).
What is the scientific name?
The scientific name of the spinner dolphin is Stenella longirostris.
What is the classification?
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Delphinidae
Genus: Stenella
When were they first described scientifically?
Spinner dolphins have been around for millions of years but were first scientifically described in 1828 by British zoologist John Edward Gray, who named the species. They are sometimes referred to as long-snouted dolphins.
