10 fin-tastic facts about dolphins

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Written by Reef-World

Celebrating Word Dolphin Day with some fun facts!

They’re clever, they’re dexterous, they’re oh-so very playful. Dolphins might be (arguably!) the most loveable creatures to grace our waves. So, what is it about dolphins that humans find so darn endearing? For World Dolphin Day on April 14th, we’re raising our flippers in celebration of these charismatic mammals. Here are 10 fin-tastic facts that will make you love dolphins even more. 

They’re super intelligent

Did you know that bottlenose dolphins are one of the few species – besides humans and apes – that can recognise their own reflection in the mirror? Yup. This rare ability is thought to be reflective (pardon the pun!) of their intelligence. 

And this isn’t the only sign of their highly evolved brains. Dolphins are also one of the few species of animals on the planet that have been observed to use tools. Scientists in Western Australia documented dolphins wearing sponges over their beaks as they hunt for fish to protect them from craggy, sharp rocks. Smart!

They love to chat

Dolphins love a chinwag. As a matter of fact, they have some of the most extensive acoustic abilities in the whole animal kingdom. Their range of vocal sounds – which include clicks (obviously), whistles, barks, moans, groans, yelps and squawks – are used in both communication and echolocation (i.e. finding objects by reflecting sound). 

Their impressive vocabulary is yet another sign of their high intelligence and levels of consciousness. Some scientists have even likened their highly developed language skills to that of humans. 

They don’t just live in the ocean

Although most dolphin species call the oceans their home, there are several river dolphin species. These guys live in fresh waterways across Asia and South America - including the Amazon River Dolphin (otherwise known as the ‘Pink River Dolphin’ because, well, it’s pink!). 

River dolphins play a huge role in the overall health of waterways. In fact, when freshwater dolphin populations are thriving, it's a pretty good sign that the rivers are flourishing too. Sadly, all five species of river dolphin are considered either endangered or critically endangered due to threats such as unsustainable fishing practices, over-development and river pollution. According to the IUCN Red List of Threatened Species, at the time of writing, the different species of river dolphin were listed as: 

But there is hope. Conservationists have pledged to tackle these issues with a goal to end their decline by 2030.  

They can live to a ripe old age

First things first, we should clear something up. It may come as a surprise to you that orcas (or ‘Killer Whales’) are actually – you guessed it – dolphins. It’s a popular misconception. But these fellas are actually the largest species of dolphin in the world and can grow up to a mighty 32 feet in length.

If that’s not impressive enough, orcas are also one of the few mammals that go through the menopause and – get this  – can live to up to 90 years old in the wild (compared to bottlenose dolphins which have been known to live past 60 years old, which is still pretty impressive)! Scientists have found that the reason behind these long-living grannies is to carry vital knowledge to boost the survival of their grand calves. Go orca-grannies!

They’re highly social beings

You’re unlikely to stumble across a loner dolphin in the wild. That’s because dolphins are famously social beings who, depending on their species, are known to travel in pods of around 2–30 individuals. Not only does ‘pod life’ play a key role in protecting dolphins from predators, but it also provides an opportunity for socialisation, play and hunting in numbers.

Serious socialites can even be found mingling in massive pods of up to 100 or even a thousand dolphins! These super pods usually only form during mating events or when food is particularly plentiful. Afterwards, the dolphins will return to their smaller social gatherings of close friends and family. Aww!

 

They like to lend a hand (or fin)

Ready for your cockles to be well and truly warmed? Get this: dolphins are thought to be ‘reciprocal altruists.’ This means they go out of their way to help and protect their kin. Anecdotal evidence has shown that dolphins will often stay and help injured pals, even nudging them to the surface to allow them to breath. But wait, it gets better...

Their compassion isn’t just confined to members of their own species. Dolphins have also been reported to help humans, seals and even whales. In one instance in New Zealand, a bottlenose dolphin amazed conservationists by allegedly responding to the distress calls of two stranded pygmy whales. The dolphin was observed guiding the whales along the shoreline and out to sea.  And the ‘Congeniality Award’ goes to….

They sleep with one eye open

Yes, dolphins sleep with one eye open. And no, it’s not because they’re on the run! Dolphins – like our whale friends – can’t breathe automatically. In other words, they have to decide when to take each breath. You’d think this would pose a challenge when it comes to sleeping but dolphins are expert nappers. That’s because they’ve got a nifty trick up their sleeves, er, fins.

When it’s time to rest, dolphins have the amazing ability to only allow one half of their brain to sleep while the other half stays on high alert, keeping an eye (literally) on dangers or predators. This kind of sleep is called ‘unihemispheric sleep’ because only one hemisphere of the brain sleeps at a time. Clever, eh?

They have the longest memories of any mammal

They say ‘elephants never forget’ but it turns out dolphins can give nellies a run for their money! Scientists have discovered that dolphins have the best social memory of any non-human animal. A 2013 study found that, even after 20 years of separation, dolphins are able to recognise the whistles of former companions. 

Researchers put these long-term memories down to the complex social connections that dolphins have evolved. Because dolphins have a fluid social arrangement (i.e. they can move in and out of different groups), it’s important for them to remember who they do and don’t want to mingle with. In other words, they’ve got a ‘naughty and nice’ list.

They know how to have fun

Dolphins always look rather chipper, don’t they? Well, this is largely down to the smile-like curvature of their beaks which gives the false impression of a beaming grin. This charming characteristic can be somewhat deceptive – particularly in the case of long-suffering captive dolphins. However, wild dolphins really do like to have fun.

If you’ve ever been lucky enough to see dolphins in the wild, it’s pretty obvious when they’re having a good time. Dolphins love to show off their underwater acrobatics, often leaping high out of the water and riding the waves of passing boats (otherwise known as ‘bow riding’). They’ve even been spotted playing with humpback whales and creating make-shift toys out of the air bubble rings they create by blowing air in a water vortex. Genius!

They can self-medicate

Coral reefs provide endless benefits: from coastal protection to vital habitat for 25% of marine life. But did you know they’re also known as ‘Medicine Chests of the Sea?’ Scientists have found heaps of healing properties in coral that have helped researchers develop medicines for a range of illnesses.

“But what’s this got to do with dolphins,” we hear you cry? Well, it turns out dolphins have unlocked the medicinal wonders of coral too. Scientists in the Red Sea have observed some unusual behaviour in Bottlenose dolphins who were seen ‘self-medicating’ by rubbing their bodies on Gorgonian corals. It’s thought that the anti-microbial properties found in the mucus of this particular species of coral could potentially protect the dolphins from infection. Better yet, they may even provide medicines for humans. That’s what we call an all-porpoise reef!

That wraps up our 10 favourite facts about dolphins. Do you have a favourite dolphin fact? We’d love to hear it!

Written by Hannah Hesford