I'm from south-west Australia (where these dolphins were observed) and grew up swimming along the coast, scuba and snorkelling to much delight.
Once, in a little sand hole near Yanchep, I was floating around on a particularly hot day, when I thought I saw a crayfish just lolling around on the ocean floor. Diving deeper to get a closer look, I realised it was just the head of the crayfish, long-since hollowed out, albeit with a bit of flesh still onboard.
I took an even closer look, and what I thought was a bit of weed attached to it was actually a long, slender tentacle, which I followed back to a minuscule hole in the rocky sand, and therein I spotted the rest of the octopus.
Delighted, I stuck around for a while to watch.
The octopus was fishing! It held out the cray corpse just a little, out in the currents, waiting patiently for the stupid little white fish to come and try to nail a bite!
When a particularly dumb little fish got its fangs in, BAM! Out came another tentacle, fast as light, and snatched that dumb fish into the hole. All the while, the original bait tentacle continued to just lull about, swinging and swaying, getting those dumb fish even closer and closer, ever more tantalising.
I stayed and watched it all day - it apparently had a nearly-insatiable hunger, or maybe it was just really enjoying itself. To my dying days, I'll never forget that clever little cephalopod ..
Dunno, Merriam-Webster list it as both,[1] though from your comment I get that it is most commonly understood as the store. Thanks for the tip though, I was only aware of the food meaning.
I doubt that. There are huge batches experiments (performed by zoologists) experimenting the limits of octopus intelligence. Some have demonstrated that their tentacles have some limited brain power on their own, being able to perform some limited reasoning and problem-solving when isolated from the central brain.
No, in the experiment I read about they forced the tentacles to go out of the water to reach some hidden area, which apparently somehow disconnects the tentacle sensitivity and reasoning from the "central unit".
Speaking of cuttlefish, there was a cool paper in Science last year about how they actually exploit chromatic aberration in the pupil to see colors - it's been an open problem for years in biology how cuttlefish can obviously react to color, yet their retina only has one type of cell so their vision should be monochromatic.
I once saw fresh octopus prepared at a seaside barbecue place. The first thing the octopus did after the cook grabbed it from the kiddie pool full of seawater was to wrap its tentacles around her forearm. Before it could get too firm of a grip, she threw it down on the concrete floor with a loud smack and disassembled it with a cleaver while it was still stunned. It was pretty intense. I can see why the dolphins would have a complex strategy for dealing with the much larger octopus they consume.
Now that it's become clear that the octopus is an intelligent creature capable of solving problems and making plans, I'm going to eat less sophisticated mollusks and leave octopus to the dolphins.
I'm with you, I can't stand the thought of eating them. They're just too darn smart, and seem really aware of you. I've swum all over the world, and any time I get a chance, I'll easily change my plans just to hang and watch a cephalopod in the wild. Thing is, too many times I've felt the situation reversed - that I'm swimming along, and the octopus are watching me, hanging out, trying to learn what this strange creature is up to in their ocean.
I used to love eating octopus particularly in sashimi form or nigiri, after learning more about their intelligence and behaviours I find my self increasingly unable to eat them... While I understand why I have developed this response in respect to a relatively intelligent animal... it's a shame because they really are so damn tasty. In other words I totally get the dolphins.
I'm not one to judge either way, but I think it's very weird how we have aversions towards eating "intelligent animals" like whales or octopi, while no-one bats an eye at the large-scale slaughter and eating of clearly intelligent mammals that form tight-knit communities and show very complex behaviour like empathy, reasoning about and solving puzzles, even the ability to play simple computer games via joystick - I'm talking about pigs.
I find the hypocrisy amusing. There are people who go apoplectic over dog eating in some parts of Asia but have no problem with pig eating in the west. Pigs have a similar level of intelligence to dogs but it's ok to grow, slaughter, butcher, cook and eat the pig.
Moral values aren't necessarily utilitarian, culture and human nature is wrapped up in it. Babies have a similar intelligence to pigs but people who eat babies are considered kind of jerks. Even if you're the mother who made the baby it's frowned on to eat the baby.
And it's sort of interesting you bring up Asia considering that the outrage over Asians eating dog meat is much greater in Asia than it is in the West. Dogs are more and more seen as pets and not fit for consumption. Worldwide, dog meat consumption has trended sharply downward.
I eat bacon. Does that make me a hypocrite? I guess. Is that an accusation likely to make me start eating dogs or stop eating bacon? No.
I think it's because we've mostly had a master-slave relationship with pigs, but dogs have always been a (lob-sided) partnership.
The other aversion is the efficiency of dogs as food, being carnivores it takes a lot more resources to raise dogs for food than it does for pigs. Any society that went for dogs were going to get out competed.
I call those specific people on their hypocrisy when possible. My brothers even had a pot-belly pig as a house pet at one point. They said it acted basically like a dog in terms of personality. So, unethical to kill dogs but not smart animals that act like dogs? Ha...
I dunno, managing to convince the alpha species of the planet not to eat then and instead to provide them shelter and food with no expectation of work in return could be considered pretty smart.
I'm quite sure that said alpha species is providing far more pigs with food and shelter than dogs. The suicidal strategy of being tasty seems to work quite well on the species level.
The "threatened conditions" is a bit more debatable, e.g. the minke whales that are being caught today by Icelandic and Norwegian whaling are of the same endangerment status as e.g. moose and wild boar - "Least Concern". Also Greenpeace et al. use quite a bit of disingenious reporting, e.g. talking about Icelandic fishing of "endangered whales" when those whales aren't actually endangered in the oceans where the Icelandic vessels fish, but literally on the other side of the earth. (I'm not particularly pro-whaling either, just food for thought.)
Octopi are even less endangered, the two large species are not on any conservation list.
Dolphins also don't seem to have qualms about raping and other violent behavior. I don't think humans should base their ethics around what a dolphin would do.
But there are many, many differences between humans and dolphins. We're smarter, for one. Debate philosophy. Are rarely seriously in danger of starving. Have much more culture. Etc., etc.
Sometimes they died from this cause, yes. The problem is not the available food, is the non-food items present also in the same place. Stomach blockages are not uncommon.
Dolphins are clearly intelligent, but not smart enough to organize a colony of many thousands of permanent shelters, and share community surplus that advances a dolphin civilization that benefits those who participate.
So, probably as intelligent as nomadic pre-historic humans. I wouldn't rate that as "highly" intelligent. Just somewhat intelligent.
These are still pre-historic dolphins, since they don't seem to record history for themselves yet. If they carry oral traditions, they seem to be limited to hunting techniques, and not specific events and personalities measured across time. There is no evidence of symbolism invented by dolphins.
So what? They're under water. If anything that makes it easier to alter their environment with lasting effects. In calm waters, it would be trivial to dig trenches and stack rocks, to create structures, as hunting traps or dens.
Either way, the octopus is similarly prehistoric, despite readily prehensile appendages.
Nor does a lack of hands readily explain the level of elephant intelligence, given a prehensile trunk.
"Apex predator" is a species category, and our species is so efficient at hunting that most of us never have to be involved with any aspect of the process save the end product. If that doesn't qualify for "apex predator", what does?
I've only found a few posts that describe the taste of dolphin. This entry (https://www.wideislandview.com/2010/03/28/bon-appetit-what-i...) described it as tasting like liver with a beefy texture. That doesn't sound terribly appetizing to my personal taste.
for clarity, though sometimes called a "dolphin", mahi mahi is a fish, not in the Mammalia class, like an actual Dolphin... so they are quite different.
I don't think that's it. It's just a matter of choices. We can eat things like fresh sourdough bread and kimchi which are also very tasty. Dolphins are fighting for survival every day. I suspect life will only get harsher for them as the oceans are dying. We have supermarkets. They have limited choices.
Killing and eating a pig when you need it to survive is not immoral. Killing a pig because you felt like having pork rinds, and then leaving the rest of the body to rot because you'd rather have steak is immoral.
While there are dolphins who won't eat octopuses because it's dangerous or difficult, I bet there are some who won't because they empathize with them. If the humans in this thread can empathize with an octopus why couldn't a dolphin?
"Killing a pig because you felt like having pork rinds, and then leaving the rest of the body to rot because you'd rather have steak is immoral."
But when does that happen? Wouldn't the butcher or supermarket usually sell most of the meat and the rest of the carcass is used for dog food or whatever?
I suppose there is probably some waste, but I find it hard to believe there are animals left to rot as you describe simply due to economics.
Sure, I wasn't posing it as a common social problem, just an example of a kind of killing-for-food that would be widely understood as unethical.
Personally, I think consumption of more than a few ounces of meat per week is unethical, by the same logic. It's not necessary for health. However, most people in my country don't have the food culture necessary to make adequate non-meat-based dishes. We weren't all born in a family where we were taught thrifty cooking techniques. So it's a strange gray area of "unnecessary". One doesn't need to eat more than a couple ounces of meat, but one needs food and if one doesn't know how to cook plants into something that could stand in for meat in a satisfactory way, then they "need" meat.
The internet is there, so anyone could do it though. I think whether it's ethical comes down to how much free time you have and how comfortable you are with cooking. But again, that's my personal view. I wouldn't expect someone else to live by my ethics. I would expect them to have some measure of "need" in their scheme though. If their habit is "I eat as much red meat as I want I don't even think about it", unless they're and abuse victim or something that's probably not an ethically defensible position.
There's very little waste in distribution. I read an article about chicken processing (I think it was on HN, in fact), and was amazed to see where all the pieces went - e.g. chicken feet from a processing in Arkansas were flash frozen and shipped to China. Parts that aren't edible by people get ground up and used for feed or fertilizer.
The waste is almost entirely on the consumer side.
It depends on what do you interpret as ethics in any case. We fall often on the trap of those rubber abstract concepts. Dolphin can not read an ethics treatise obviously, but show lots of examples of what most people would call "ethical behaviour":
Cooperative hunting, altruism, care for the members of the group, and colective child care are normal.
Innate interest and sense of compassion for other marine mammals in distress, including humans, and a strong protection response in dangerous situations.
They have grandparents. This is particularly remarkable. Old specimens past their reproductive days are treated as expendable and die quickly in 99% of the animal species. Grandma's are instead VID (very important dolphins) in its societies, and live much longer than expected.
"Even a potato in a dark cellar has a certain low cunning about him which serves him in excellent stead. He knows perfectly well what he wants and how to get it. He sees the light coming from the cellar window and sends his shoots crawling straight thereto: they will crawl along the floor and up the wall and out at the cellar window; if there be a little earth anywhere on the journey he will find it and use it for his own ends. What deliberation he may exercise in the matter of his roots when he is planted in the earth is a thing unknown to us, but we can imagine him saying, 'I will have a tuber here and a tuber there, and I will suck whatsoever advantage I can from all my surroundings. This neighbour I will overshadow, and that I will undermine; and what I can do shall be the limit of what I will do. He that is stronger and better placed than I shall overcome me, and him that is weaker I will overcome.'
"The potato says these things by doing them, which is the best of languages. What is consciousness if this is not consciousness? We find it difficult to sympathise with the emotions of a potato; so we do with those of an oyster. Neither of these things makes a noise on being boiled or opened, and noise appeals to us more strongly than anything else, because we make so much about our own sufferings. Since, then, they do not annoy us by any expression of pain we call them emotionless; and so qua mankind they are; but mankind is not everybody.
From Samuel Butler's Erewhon. (The same chapter that inspired the eponymous Butlerian Jihad in Dune, incidentally.) I don't agree with the conclusion here, and I doubt Butler did either, but the whole book is a great read.
Can I present a perspective to distinguish between potato and animals, so we can decide what to eat or not? Personally I have found it be quite useful. I hope some SW engineers can relate to it.
"Sadhguru: Now, if you eat a mango, this mango becomes a woman in you. If I eat a mango, the same mango becomes a man in me. If a cow eats a mango, the same mango becomes a cow in the cow. Why is this happening? There is a certain information or software in you – whatever you eat it transforms it into a woman. If I eat, it transforms into a man. If a cow eats, that becomes a cow. So every life is happening the way it is happening because of a certain dimension of information or in modern terminology, let’s call it software. There is a certain software, which is an arrangement of information.
Now, the idea is to eat as simple a software as possible. If you eat that kind of life, which is a very simple software, your ability to override that software and make it entirely a part of you is very good. As that software gets complex, more and more complex, your ability to integrate it goes down. So, especially if it’s a creature which has some sense of thought and emotion, if it has emotion, then you should not eat it. This is the understanding. An animal, which has any emotion, displays certain emotions… especially if it displays emotion which is near to human emotion, you should not eat it because it will not integrate itself. That animal nature will start manifesting itself."
I could eat babies and they would keep me alive. How does one tell if they are able to "integrate" their food without the baby nature "manifesting itself"?
Perspective is a point of view. This perspective definitely has no basis in hard science (as of today) but is not "nonsense". To decide whether to eat an animal or not is an ethical/moral question (unless the animal is poisonous). This model allows you to answer that question. Also models like this are quite common, for example - karma, meditation, etc.
And, this idea is in Western civilization too. Look at the origins of the phrase - "you are what you eat".
Yes potatoes are as intelligent over the course of a year as an octopus is in a few seconds. But that means killing and eating a potato plant is morally more equivalent to beating and detaining an octopus for a little while than killing and eating one.
I really don't get why this reasoning is not extended to other animals as well. For example, people do eat cows, pigs, dogs and they are pretty smart as well (much more than plants). I think it boils down to "culture" of the place you grew up. Maybe in your country people never ate octopus but in country X (China? Korea?) they never had any doubts about eating octopus.
>I know anthropomorphizing animals is a no-no these days
Well, I think you are making a good point here, so I wouldn't write it off on that basis. In the rush to avoid anthropomorphizing animals, people sometimes go to the opposite extreme and assume that things like "taste" are uniquely, exclusively human experiences and can't be extended to animals.
That seems to attribute full ownership of a category of experience to humans, and to me that kind of assumption is more problematic, if we're talking about the excesses of anthropocentrism. I think your explanation makes perfect sense.
"Pufferfish produce a potent defensive chemical, which they eject when threatened. In small enough doses, however, the toxin seems to induce "a trance-like state" in dolphins that come into contact with it"
There are reports of dogs repeatedly licking the toxic cane toads in Australia. Some are speculating the dogs are "addicted" to the "high" from a non-fatal dose of the toxin the toads excrete in their sweat. http://www.huffingtonpost.com/2013/12/17/dogs-licking-cane-t...
Some potentially deadly foods are considered a tasty delicacy. See, fugu [0]. Which can be really, really really poisonous [1]. It makes cyanide seem harmless in comparison.
Although I just learned from Wikipedia that apparently we figured out how to raise non-poisonous pufferfish. Neat.
you can get that in koreatown in LA as well (probably elsewhere too but that's where i've had it). the taste is pretty subtle but it's weird that it squirms in your mouth.
It's a competition of sorts. There used to be people where I work who would one-up each other on spicy food. They were long past the point where you could actually taste anything but the "heat", but they wanted to see who could take the most punishment.
I have a Japanese friend who explained the fugu thing to me (at least, the way he saw it). Every once in awhile a group of people die when they eat fugu that's not prepared properly. So when you go out with your colleagues you try to work the latest such incident into the conversation, and then you order fugu. The goal is to eat it with the supreme nonchalance while trying to make your coworkers visibly nervous.
I have practiced eating spicy food in Singapore. But I was still well within the "this can be tasty" envelope.
> The goal is to eat it with the supreme nonchalance while trying to make your coworkers visibly nervous.
We eat raw pork mixed with raw eggs and raw onions on a bun in Germany. But nobody there thinks it's particularly dangerous. (https://en.wikipedia.org/wiki/Mett)
I have more than ten years of experience studying cetacean diets and have personally retrieved and identified several octopus, squid and cuttle species in dolphins and seals stomachs. I know what I'm talking about.
On the other hand, many people eat octopus, some even eat it alive. If eating octopus would produce the slightest drug effect, I think that we, humans, will know it :-)
And yes, of course there is a lot of bibliography available about dolphin behaviour.
I have seen dolphins swim in the wake of a ship and I strongly believe they did it just for the kick of it. Maybe they showed off to the dolphin girls, who knows?
Even more than that it is believed by many. The idea being humans evolved to enjoy sweet for the reasons you pointed out - it means carbohydrates which are dense in calories. Humans evolved to enjoy a certain amount of salt as it is essential to our survival; bitterness tends to be found in toxic things and is generally not palatable as a last warning to avoid ingesting bad food; Sour can be enjoyable but it also signals under ripe fruit and rotten meats as well as dangerous acid levels in some instances. Umami is thought to encourage the consumption of important amino acids.
It makes sense that earlier ancestors who maybe found bitter very enjoyable and sweetness not so enjoyable died off from a lack of calories or eating poisonous things before reproducing. And it makes sense that while across cultures people eat very different foods, you see the same patterns in terms of umami and sweet being considered desirable and bitterness often rejected.
In fact the human tongue is considerably more complex than traditionally assumed. For example, besides the umami taste receptors recently proven to exist there are also studies looking to see if we have taste receptors for "fat", "starch" and even "metallic" flavors, among other things.
The chemical reaction between molecules and how the brain decodes the signals produced by them is fascinating when it comes to the flavor of things.
I think reading the article that the risk is much overstated for sexy story-telling purposes. Dolphins of course do not choke if their mouth is full or blocked. They breath by the spiracle in the top of their head.
I would even argue it's the opposite. The book by biologist Frans de Waal - Are We Smart Enough to Know How Smart Animals Are?[1] was in a lot of best book lists.
It's a no-no always because it's poor reasoning. Saying "these days" is a way to paint it as some kind of fashion above which the commenter is. In this specific case, I reckon dolphins have taste buds too, so it isn't really anthropomorphizing. I think it's a good hypothesis.
Actually, it's the "we shouldn't anthropomorphize" which is poor reasoning. Because of course we should, we should just call it something else.
I am not really aware of any mammal behaviour that I cannot somewhat relate to at gut level. You may say I anthropomorphize, or you may say I equate, it doesn't really matter. There isn't a physiological or neurologic feature we don't share, me and all those other mammals. I have some language and some reasoning power to top it all off with, but our sensations, reactions, emotionals, motivators, fears, pains and joys are clearly of very similar nature. Of course they are - they run on the same basic hardware architecture.
And now, if you will excuse me, my dog wants to go for a walk. I know exactly what he means.
This is my line of thinking as well. Physiologically we are extremely similar to other mammals, especially when you take a look at the extreme fringes of life and realize how utterly different from us it can be. It's logical that large portions of our life experiences are the same, too. The differences are mostly fine details.
If you want to find where our perceptions differ from that of a cat or a dog or an elephant, I believe that anything cultural or learned in nature is a better place to start. If every human experiences it, it's likely that other mammals experience it too on some level.
I suspect that if our experiences shared few or no similarities, humans would've had far less success in the way of keeping, training, and befriending animals. The ability to accurately empathize with other creatures has to have jump-started the process in many cases.
Neither your example or the start of the thread seem like anthropomorphizing. Both "liking" the taste and "enjoying" outdoors or exercise are well established reactions in numerous animals. Anthropomorphizing is most easily described as the subject using human-like reasoning or rationalization. Sure, the classic definition is broader than that with angry weather. I do agree with your point regarding g mammalian comparisons, but it's not clear to me that was demonstrated.
I fully concur. We and other mammals inherited many of our behaviors such as emotional attachments, social bonds, play, etc from common ancestors. It seems reasonable to me that our experience of these is similar to that of the common ancestor, and therefore that other Mammals experience of them is also similar to ours. Not the same maybe, but similar.
I am saying "these days" because from what I understand in past times anthropomorphizing animals used to not be as frowned upon in literature. I might well be wrong though of course! If so apologies, I did not mean to imply it as a fashion or as a negative, just that sometimes I feel that the simplest explanation (dolphins like a treat) should win over the more complex one (octopuses must have some great nutritional value)
This makes me think of primitive humans working together to kill large animals for food.
Super dangerous and only possible when working together.
Perhaps one day, thousands of years from now, technologically advanced dolphins will one day watch us doing the same thing again, and they will have a similar article about us!
> Perhaps one day, thousands of years from now, technologically advanced dolphins will one day watch us doing the same thing again, and they will have a similar article about us!
I'd be curious to know how much of human technical advancement was thanks to the ability to relatively easily smelt metal, and whether the inability to easily smelt underwater creates an impediment to technical advancement of species living underwater.
Seawater also plays hell with ropes and hide. You can't construct with stone, because it sinks to the bottom, and the silty bottom is a rotten foundation. You can't build with wood because it floats away, it will soften and weather quickly, and things will eat it quickly. You can't wear tools, as that ruins your streamlining, and fast swimmers will generate high drag forces on anything they wear.
Interesting thought! On the other hand, what is the point of building stuff if you don't need protection from rain and snow, vast swaths of ocean are just the right temperature for you, you can sleep with half your brain at a time while swimming, and you are not interested in stockpiling food for later?
I have a feeling that what dolphins lack in material culture, they make up for in social life, poetry, philosophy, and music.
They're probably looking at us with pity: "Their pod dynamics wouldn't be such a mess if only they didn't waste so much time and effort building stuff..."
(Okay, okay, I know a lot of you people love building stuff...)
If anyone's interested, I really enjoyed Voices in the Ocean by Susan Casey as a look into how advanced dolphins may actually be. She explores scientific facts and even interviews "kooky" new-age people who swim with dolphins daily to get their POV. I was convinced that at least there are dimensions to dolphins' lives that traditional marine biologists are totally unprepared to touch.
Perhaps in a future age, spacefaring civilizations will say the same thing about primitive life forms living at the bottom of gravity wells. How can you get anywhere with so much gravity holding you down?
You can still build edged tools, weapons, clocks, and computers at the bottom of a gravity well. Being aquatic is completely different -- the environment often keeps you from evolving manipulators for building tools. Even if you evolve the manipulators, the environment automatically degrades the value of the tools.
Having opposable thumbs is a pretty big deal. One Arthur Clarke short story that has always weirdly stuck with me is "Second Dawn" - which revolves around super-intelligent telepathic horse-like aliens, who have sadly limited technology because they only have hooves.
We will be able to speak with dolphins within 40 years because of augmented reality. 20 for the hardware/software foundation and 20 to raise adolescents who are adapted the augmentation.
The only reason we haven't been able to communicate with them is we haven't found a good mutually comprehensible input medium for them. HMDs could be it, positional audio might help. But either way VR as a metaphor for UI will get researchers thinking in new ways about input as we go deeper into VR ourselves.
Presence will be the Rosetta Stone for animal language. "You are here and this is happening" is orders of magnitude harder to ignore as an atom of communication than a computer screen on the wall of a talk.
We will be able to record entire naturalistic experiences of a dolphin, and then give them an AR keyboard to play back arbitrary slices of it in sequence, and do the same for their friends.
Early dolphin language will look like hip hop music or poetry in structure (a pastiche of samples), and we will quickly find out whether they have the neuroanatomy for grammar.
I think one barrier may be that we're not that interesting to them. Perhaps, rather than sending literal-minded scientists to attempt communication, we ought to send poets and musicians.
I read of a recording of an upset, irate dolphin's sounds. When slowed down significantly, it was clear the dolphin was mimicking it's trainer's reprimands. So, one clue is that their processing speed is way higher than ours.
I also read of a researcher who set out with a box that could make dolphin sounds, and she wanted to teach dolphins to say names she has made up for three objects, with disappointing results. But I'm wondering... these are creatures that can be taught a command that means "innovate" - do something different that you haven't shown me yet today. A rule of their language might be never to use the same word twice.
Also, dolphins are aware of one another's sonar. So, they would never need to vocalize "Look at that over there." They already know what pod-mates are paying attention to. Possibly they wouldn't find it interesting to use nouns to refer to things that are already obvious on the pod's echolocation radar. Their verbal channel might deal with less concrete things like mood, nuance, intuition, and humor.
>Sprogis and colleagues muse that the nutritional value of an octopus must be "substantial." Or, as marine biologist Holly Bik points out at Deep Sea News, maybe it's just that "dolphins are a$$holes."
It seems surprising that an octopus leg hitting the oceans surface 15 times kills it.
I can't imagine that a dolphin can throw an octopus leg at more than 15-20 mph, and at that kind of speed I wouldn't imagine damage to a soft bodied creature.
I would imagine a better technique to be to leave the octopus legs for 10 minutes for lack of bloodflow to kill it. Wonder why they don't do that? Too hard to defend a bleeding morsel of food from other predators?
If you watch the video, it's not just throwing the leg, there's also a behavior where they hold the legs in their mouth and slam it into the ocean as hard as they can by bending sideways. Considering dolphins use those muscles to swim, they are likely very strong, considerably stronger than human arms tenderizing meat with a mallet like we do.
I don't see why you would think leaving the legs alone for ten minutes would be as effective as hammering them for ten minutes. What's going to bleed out and go lifeless quicker, an arm left alone or an arm being beat on?
I suspect the defensive mechanism in the octopus leg is triggered by the impact. After a number of impacts the remaining energy in the leg is exhausted and it can no longer harm the dolphin.
Interesting survival technique, if I can assume it is. The octopus in question dies but the dolphin who tried to eat it does also. Serves as a warning to dissuade eating the species/order as a whole. Same as poisoned toads in that regard, just a little more zombie-like.
It's not clear to me that they're "risking death."
The article reveals that dolphins can be killed trying to eat octopus in a more conventional fashion, but I don't see any "risk" involved with their throwing method.
What about if they don't throw it enough times to stun it? Or if that particular octopus is particularly stun-resistant? Or if the dolphin hesitates at some point in the grab-and-throw maneuver, giving the legs a chance to grab on to its face, mouth, or throat? It seems like there would be a lot of opportunities for error.
Dolphins haven't developed the kind of jaws necessary to chew substantially like a human, who chews with molars. Also humans still can choke to death on octopus.
I wager that the whole purpose of throwing the tentacles into the air is to provide the dying organism with a lack of stimulus to the neurons in the tentacles for a few seconds, on water impact, the renewed stimulus would make the tentacles move. I reckon after a few tries the tentacles just run out of energy.
The octopus and likely the dolphin is probably much smarter than we give them credit for. On a whim one day I studied the octopus and finding them majestic and so smart I stopped eating them. The kicker was when I learned that female octopus when giving birth find a rock out of sight of predators and spend their last days and minutes doing nothing (no eating etc) but waiting for the next generation to birth and then they subsequently die. It was moving.
I've seen this behaviour with seals when kayaking. Fascinating to watch, and I swear they were just showing off to us bunch of humans hanging out enthralled by the sight of a large seal slamming the octopus over and over again against the water until it was dead enough to disappear with back into the deep.
I would like to challenge my hard-core religious physics and biology teacher from 7th grade with this evidence. He kept giving me as low a grade as what was acceptable, while I still aced pretty much every test. (Sweden. Småland. 90s. I don't think this is an issue for todays kids.)
I'm from south-west Australia (where these dolphins were observed) and grew up swimming along the coast, scuba and snorkelling to much delight.
Once, in a little sand hole near Yanchep, I was floating around on a particularly hot day, when I thought I saw a crayfish just lolling around on the ocean floor. Diving deeper to get a closer look, I realised it was just the head of the crayfish, long-since hollowed out, albeit with a bit of flesh still onboard.
I took an even closer look, and what I thought was a bit of weed attached to it was actually a long, slender tentacle, which I followed back to a minuscule hole in the rocky sand, and therein I spotted the rest of the octopus.
Delighted, I stuck around for a while to watch.
The octopus was fishing! It held out the cray corpse just a little, out in the currents, waiting patiently for the stupid little white fish to come and try to nail a bite!
When a particularly dumb little fish got its fangs in, BAM! Out came another tentacle, fast as light, and snatched that dumb fish into the hole. All the while, the original bait tentacle continued to just lull about, swinging and swaying, getting those dumb fish even closer and closer, ever more tantalising.
I stayed and watched it all day - it apparently had a nearly-insatiable hunger, or maybe it was just really enjoying itself. To my dying days, I'll never forget that clever little cephalopod ..