We all know that dolphins are smart, but here’s a behavior they’ve come up with that is truly awesome. From BBC’s “One Life,” watch what these clever mammals can do:
The Japanese are still killing these magnificent beasts for meat (and for sale to aquaria).
h/t: SGM
thanks for sharing! amazing! The dolphins, not the Japanese!
I’m curious about the evolutionary logic by which the fish feel that the safer option is to leap over the silt barrier instead of swimming through it. Obviously they’re right to think there are predators lurking in those clouds, but are their chances of survival really any better in the air than in the water?
Or maybe there are some fish choosing the water option, but we just don’t see them in this video.
I’d be curious whether fish can swim through the clouds. Would the silt be harmful to their gills?
Good question. I was assuming they avoid the clouds because not being able to see puts them at a disadvantage compared to echolocating dolphins.
On the other hand, once airborne they lose the ability to maneuver. So it’s a no-win proposition for the fish either way.
Maybe the fish aren’t a species that’s used to high levels of turbidity and mistake the silt for a solid object.
That occurred to me, but I dismissed it because I figured the fish could see the dolphins stirring up the silt. But maybe I’m giving the fish too much credit.
As far as I know, fish in general tend to have more brain function devoted to processing sensor input than they have devoted to problem solving ability, so they tend to have very quick reaction times and good senses but are more limited in the number of responses they can come up with for situations.
Or I could have no freaking clue what I’m talking about, wouldn’t be the first time.
I would think the fish have no reason to assume the silt doesn’t go on for a long distance, i.e., that it is not just a curtain that they could swim thru and in a moment be on the “other side” back in clear water.
Also I would expect fish to lose their schooling abilities in a vast expanse of muddy water, which puts them at a disadvantage.
All speculation.
With that much silt on the sea bed any storm or even high winds would rapidly increase the turbidity of the entire area. I think you might see the same prey behavior if the dolphins simply circled the fish without stirring up the mud. Jumping is a strategy schooling fish use to evade predators. The mud renders sight less useful, but sight isn’t their best sense. The fish can still detect their predators by smell, taste (they have taste buds on their lips as well as inside their mouths) hearing and vibrations and movement with their lateral lines.
So it’s a species of fish that has a default reaction to being disturbed of “jump out of the water” like the Asian Silver Carp in the Mississippi?
I think the fish are jumping in response to the presence of a predator which they sense by means other than sight in the muddy water. I don’t think it’s a generalized response like the Asian Silver Carp. The mud nets may cause confusion and panic to the predators advantage serving up an all you can eat buffet, but I think the dolphins might have a meal if they simply swam in an ever tightening circle without the benefit of the camouflage although they would probably spend more energy doing so without the benefit of the mud nets. (I’m speculating.)
“The Japanese are still killing these magnificent beasts for meat…”
I read the tone of that remark as disapproving; it prompts me to ask whether killing dolphins for food is more reprehensible than killing, say, pigs for food. As noted in Natalie Angier’s article:
http://www.nytimes.com/2009/11/10/science/10angier.html?_r=0
they are evolutionarily close, relatively speaking, to dolphins, they are likely of equivalent intelligence, and they are as socially sophisticated.
Pigs are not endangered.
None of the ten species of dolphins and porpoises hunted as ‘food’ in Japan is listed as endangered.
What is the difference between food and ‘food’? Is it a race thing? Or is it only food if it fell from the tree and wanted to be eaten?
Dolphin meat supposedly tastes pretty lousy; some anti-hunt proponents have claimed that the point of the kill is primarily to reduce cetacean competition for fish resources. In the Solomon Islands, they are hunted to obtain teeth for use in jewelery. They are also hunted, as food, in the Faroe Islands and, illegally, in Peru.
They used to (rarely) be eaten around here but the meat (unlike whale) isn’t good. Dolphin’s have in their favor the fact that their jaws look like they are smiling, thus humans find them cute, and as pandas exemplify that’s all that matters. Yet, as much as I dislike cuteness driven conservation, in the case of dolphins it makes a lot of sense, even if currently they are not endangered. Hunting them should be disallowed because eating a slow breading apex predator isn’t a sustainable practice. It’s the same thing with many species of shark. Not that they are less deserving of the table than sardines, but their populations can not sustain even low levels of harvesting without crashing.
I have to agree with your basic premise, to the extent that another being is capable of suffering (despite what that moral monster William Craig Lane has to say about non humans experiencing pain), they must become part of our in group.
Of course it is disapproving. For me, it is the fact that we can kill farmed pigs painlessly as opposed to sadistically searching out the most hard, so painfully, killed animals in nature that is the big and unbridgeable divide.
Other considerations would be that dolphins are socially much more close to us such as passing the mirror test and calling each other by name et cetera, and that food pigs have been coevolved for preying on while wild dolphins haven’t.
I forgot: “… coevolved _and kept_ for preying on”. These species would not be without us!
I’m not quite sure I follow the second paragraph of your reply, but you are as far as I can tell suggesting a basis for deciding the suitability of animals for use as food. If that is the case, could you please more specifically expand on it?
We could conceivably create a species of domesticated subhumans for use as slave labor. But I hope you would agree that the fact that we created them is not sufficient ethical justification for enslaving them.
So whatever the ethical justification is for using domesticated animals for food (or any other purpose), it must have some other basis than the mere fact that they’re domesticated.
we ‘can’ kill pigs for food painlessly, but it is the case that 99% of the pigs raised as food in this country lead extraordinarily unpleasant lives and die emotionally and physically painful deaths. there are numerous, credible resources available to you to disabuse yourself of the notion that anything else is the case, if you care to.
I would like to offer here a quote from the recently and repeatedly cited Walter Kaufmann:
“…men share what Tolstoy once called a ‘fear to understand things that clash with their own customs, privileges, or beliefs’. I think we all share that fear…some of us, perhaps, are never conscious of this fear, but, still, I think all of us find, if we are very honest with ourselves that on occasion we don’t try very hard to understand things that clash with our own customs, privileges and beliefs…”
If we are guided by reason,logic, and science; if we determinedly “…follow the path of rationality wherever it leads…”, we can avoid subscribing to unfounded and unquestioned beliefs. That’s what the religious do!
Disclaimer: I am vegetarian (and mostly vegan).
I have often found that what meats people “disapprove” of is often a function of the culture in which they are brought up: rational justifications for such preferences are often arrived at after the fact. Many Indians, for example, disapprove of the killing of cows (as compared to, say chickens). Though this is mostly for religious reasons, one “rational” argument often brought forth to support this is that cows “contribute” to a lot to society: babies are put rather early on cow milk in India (the reason behind the epithet “Mother Cow”); they have historically been indispensable for agricultural needs, and so on. On the other hand I have met many Westerners who laugh at such reasoning, while simultaneously “disapproving” of the Chinese custom of eating dogs (“How could one eat those nice animals!”).
Torbjörn Larsson’s argument above seems to be of a similar flavour as the Indian reasoning against beef, just applied in reverse. “Disapproval” of pork is not built into most Western cultures, so post hoc justifications for eating it in preference to, say dog meat or dolphin meat, have to be found.
Exactly, hence the Walter Kaufmann quote. Dogs AND cats are eaten in Switzerland as well as in many Asian countries. Dogs are eaten in some Native American cultures; cats are also eaten in parts of Peru, Italy and Australia.
I certainly feel that I don’t have the right to kill and eat any animal (if it wasn’t for pure survival). Especially not because of the way animals are treated in the meat industry. Been veg for 10 years now and I’m not really missing anything when it comes to food.
I see most animals as friends just as I see most (well, some…) humans as friends (we’re animals too, right?). 🙂
I don’t think animals in general are my friends, though certainly some are, and I regard the vast majority with profound affection. There are many reasons to not eat meat, but I think perhaps the most important one, for me, is suggested by the quote from Plutarch:
“But for the sake of some little mouthful of flesh we deprive a soul of the sun and light, and of that proportion of life and time it had been born into the world to enjoy.”
Or, does the transient, gustatory pleasure I take in consuming the flesh of a creature justify its demise? I’m not comfortable with being that extraordinarily selfish.
This is pretty awesome, but as with many of these behaviors I always wonder whether they are really intelligent.
I don’t think it’s necessary for the dolphins to understand that waving their caudal fins in a circle around the fish will cause them to jump out of the water. Instead it’s just something that works and that may have been happened on by chance.
I would have to disagree. It seems that whenever non-human animals do something intelligent it gets branded as pure happenstance. Even if it was simply a fortuitous discovery, it indicates intelligence to have figured out the cause and effect and to replicate the behavior.
I agree, Christina, and I think Jon bagging those dolphins are not exhibiting intelligent behaviour says more about his own intelligence. 😉
I didn’t say it couldn’t be intelligence, just that people are very keen to jump to that conclusion when it’s not really clear. I’m glad a few other people further down question this as well.
I know dolphins are quite intelligent so it might be easier to assume that this is intelligence in dolphins than it would be in other species.
And thanks for the insult on my first post. 🙂
And Christina, I don’t see any suggestion that they have ‘figured out the cause and effect’. At least not more than most animals have for learned behavior.
David Attenborough showed a video of this behaviour in his series of documentaries. He considered it to be an example of intelligent behaviour.
In any case, it should be possible to demonstrate this. If dolphins learn the behaviour, then it is intelligent behaviour, not instinct.
Given that according to some of those David Attenborough documentaries it’s a behavior only found in a few populations of dolphins even though other populations are found in similar habitats, it seems like it’s absolutely a learned behavior.
Heck, on Human Planet’s ocean episode, there’s a segment about a place where the local fishermen have teamed up with the local dolphin pod: the dolphins drive fish straight into the nets and the fishermen give them part of the catch as payment. According to the fishermen interviewed, it’s not something they taught the dolphins, the dolphins started doing it on their own.
Atlantic bottle nose dolphins along the southern coast of the US between Charleston, SC and the Georgia sea islands engage in a cooperative feeding behavior called strand feeding. The dolphins swim slowly back and forth herding a school of fish closer to the shore. Then they form a line and speed toward the shore throwing a bow wave, the prey and themselves up on the land. There’s a YouTube video and an article in “South Carolina Wildlife” about this unique behavior. I’ve watched this from a kayak in the salt marshes around Hilton Head Island, SC. Occasionally a dolphin will swim completely out of the water and have to frantically wriggle its way back in. Sea birds like to get in on the action too.
That sounds similar to the way that orcas hunt fur seals off Patagonia.
Curious: Why the assumption that this is behavior dolphins figured out because “they are smart”, rather than evolved behavior by a predator that is a product of natural selection? Is there evidence to support that assumption?
Always good to question assumptions. We do see many examples of extraordinary behavior in animals that are probably more a matter of genetic behavioral programs, such as a spider building its web or a weaver bird building its nest. Here, though, I would vote for it being intelligence. The dolphin brain is among the larger brains due to body size. Dolphins are credited in showing self awareness, such as when a captive dolphin is presented with an image of itself in a mirror its reaction indicates it knows it is seeing an image of itself and not another dolphin.
If it can be shown that the behavior shown in the above video is an example of a learned ‘insight’ behavior, then we can attribute it to intelligence and reasoning. A sign of that would be if it is seen as a cultural behavior in some dolphin populations and not others.
Be careful with the brain size argument, in the case of dolphins it can be misleading, their brains are rather «primitive» in structure (close to bat and hedgehog brains). In particular they show a very thin neocortex, and have neurons with very few dendrites that are very weakly branched. The brain layers that show massive development in dolphins are the «older» mammalian brain layers.
Some whales have been observed making nets of bubbles by getting below fish and circling while blowing out air. That tends to keep the fish from bolting and herd them closer together. I believe it’s cooperative behavior as well.
It could be fun too. Different certainly, catching fish in the air. Perhaps one could do statistics on frequency and success rate, to see if it is done as “friday family fun”.
I have known that marine mammals evolved from land mammals for at least 20 years — but now I am making the explicit connection that dolphins are working with land-mammal brains.
Their brains are closer to the «primitive» mammalian brain, very distinct in organization from ours.
Awesome video. Thanks for posting. I’d say that demonstrates intelligent behaviour, equal to the order of devising and using tools.
“The Japanese are still killing these magnificent beasts for meat (and for sale to aquaria).”
Yet you probably eat slaughtered pig and cow. Where do you draw the line?
I ask this question of myself also – I eat a lot of meat.
Self-awareness, personally.
How would you define that standard? I ask because, until fairly recently, this was the rough equivalent of the rationale I used personally.
I don’t agree with the practice of dolphin hunting, but I do eat other types of meat. I do feel bad about eating meat in general. So this is a tough topic for me.
One thing that does bother me is that the focus on whaling always seems to be on Japan. Using the term “the Japanese” implies that all Japanese hunt dolphins or agree with the practice, which is not true. Clearly, no one believes that all Japanese people eat whale or dolphin, but I still think we need to be careful about our phrasing when we criticize other countries or groups of people. Many western countries hunt and kill whales and other cetaceans yet seem to recieve far less scorn.
Public demand for whale meat in Japan is in decline (just google the phrase) to the extent that, according to reports, it isn’t profitable without government assitance. Hopefully this decline will continue until the practice ceases.
Many western countries hunt and kill whales and other cetaceans
Currently, some Bowhead whales are hunted by some Inuit and other indigenous peoples in Canada, Alaska and Washington State; Pilot whales (dolphins) in the Faeroes; several mysticete species in Greenland and Iceland; Gray whales in the Russian far east; and Minkes in the northeast Atlantic by Norway (wiki). That doesn’t seem to add up to “many western nations”.
Apart from its highly localised coastal dolphin ‘hunts’ (as in the Faeroes), Japan is the only nation anywhere practicing industrial-scale whaling thousands of kilometres from its shores (Norway’s is relatively local); simultaneously claiming to the IWC that it’s research (though the published research output is pitiful, and there are much more effective and cheaper non-lethal methods for population and ecological studies) and trumpeting to the press that eating whale meat is traditional (it is relatively cheap because of subsidies, but there are large frozen stockpiles because nobody eats it much).
Oops (close tag)!