The Secret Life of Dolphins
We all love dolphins! Those beautiful, fun loving, super friendly creatures that ride the bows of our boats, and thrill us with acrobatic leaps and jumps! But what do we really know about them and how they live? Let’s take a look at some recent research!
It’s on everyone’s bucket list – that fantastic opportunity to swim with wild dolphins! Just the thought of slipping into the water with a pod of playful Atlantic Spotted Dolphins, having them surround me as I duck dive into their watery world, puts a smile on my face, and makes me start to daydream… the clear blue water, dolphins flashing past, blowing bubble rings, whistling and calling with exhilaration! It also starts to make me reflect how amazing it is that I got the opportunity to experience this!
Swimming with wild dolphins is very unique, even for dolphin researchers. It’s actually pretty difficult to find conditions where the water is clear enough to do this consistently. There’s only a handful of places where this is even possible – for example in Tahiti, Hawaii and the Bahamas. The Bahamas has a small community of very gregarious spotted dolphins, that over the years have become curious of researchers and visitors – giving us amazing opportunities to get up close to them! Let’s take a look at what the researchers at the Wild Dolphin Project have uncovered so far about our spotty friends!
Atlantic Spotted Dolphin
Stenella frontalis – the Atlantic Spotted Dolphin, is the species that visitors are most likely to encounter on a Bimini dolphin expedition. They’re relatively small for dolphins, growing up to 2.3 m (bottlenose dolphins, who are the other dolphin species resident in Bimini, are bigger and chunkier, growing up to 3.8m). And they have spots! Spots develop with age – babies are actually born totally spot free! Juveniles start developing speckles from 4-8 years old, progressing to a mottled look from 9-15 years old. Adults older than 15 years have spots that start to fuse together – I like to think they’re like freckles! Researchers use spot pattern progression to help age dolphins – no hiding behind makeup!
Bringing Up Baby
Baby dolphins are born after a 12 month gestation, and have to hit the water running! From birth, they need to be able to swim immediately, keeping up with mom and the pod. Calves stay super close to mom, relying on them for the first 3-5 years for food, and to learn everything they need to know to be a good dolphin!
What happens if mom and calf are sadly separated? Amazingly, there is evidence of group care! Researchers in the Bahamas recently observed a little female calf who seemed to be cared for by a different adult every time they saw her. Even the male adults in the pod took a turn with baby. She was always in the infant position, right under her caretaker of the day, as the group seemed to pool together to help bring up baby!
We all know that dolphins are highly social animals, living in pods. Let’s take a look at what researchers have found about the structure of their society. It looks like females in particular tend to associate based on their life stages – for example pregnant females hang out with other pregnant females, females with calves tend to group together, and teenage dolphins form their own cliques. They also appear to prefer to spend time with close family members – older female calves hang out with mom to help babysit little brother or sister.
Dolphins society is complex, with members forming alliances, friendships and relationships that researchers are still trying to understand! It’s a lot harder when you can’t interview your research subject!
Decoding Dolphin Speak
One of the super fun things about swimming with dolphins is getting close enough to hear their distinctive whistles, clicks and pulses! Are they talking to us? If only we can talk back! Over the years, researchers have recorded dolphin sounds and the actions of the dolphins making it. Amazingly, they’ve managed to associate sequences of sound with types of behaviour – identifying distinct sound sequences for aggressive behaviour, courtship and foraging. Researchers are now employing machine learning to try and identify patterns and structures in the clicks and whistles, to find out if this indicates the existence of language for dolphins!
We love dolphins because they just seem so joyful and play loving – from highly acrobatic jumps, bow riding, to playing with kelp and other objects. They seem super curious about their world. But does any of this indicate intelligence?
The mirror test is the big one when it comes to cognizition – would an animal recognise itself in a mirror? Up till 1970, it was thought only humans had sufficient cognitive ability to do this. Primates were later proven to also have this ability. And then, in 2001, step forward our friend the dolphin! A study demonstrated that dolphins as young as 4 months old can recognise themselves in a mirror – showing super high levels of cognition and intelligence! Not only that…. but human babies are only able to demonstrate this skill from 18 months old – guess we develop slower than dolphins!
Dolphins and the Environment
So what have scientists seen in terms of the impact of climate change on dolphins? Well, as the world’s weather gets crazier, hurricanes have been more frequent in the Bahamas. These can be devastating for dolphins, with an estimated 30% of the population lost due to these events. Coral bleaching, and changes in the productivity of sea grass meadows also impact their food chain. Recently it was observed that a pod of dolphins abandoned their home range of over 20 years and moved over 100 miles away, over deep water. Satellite images later showed a huge drop in plankton in their original home – dolphins as climate refugees. Imagine having to leave your ancestral land because of lack of food!
Dolphins welcome us into their underwater home with playful positivity, leaving us filled with joy and wonder. They inspire us to love nature, and motivate us to conserve it. As we see more impacts from climate change unfold, we all need to take responsibility to educate ourselves, and to protect their marine habitat.
Ninja Family Guest Writer:
Lover of all marine animals big and small – and ok, yes, I like diving a lot! When not underwater, I can be found in London with my goldfish.
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