Submitted by Snoo-82132 t3_y9a6rk in askscience
They seem to start building dams. Is it passed down from parents to children or genetically coded into their DNA?
Followup question: What is the evolutionary reason for this?
Submitted by Snoo-82132 t3_y9a6rk in askscience
They seem to start building dams. Is it passed down from parents to children or genetically coded into their DNA?
Followup question: What is the evolutionary reason for this?
Any sources? Like, was there ever a beaver adopted by a human at birth and never saw dam building and started building a dam?
Swedish biologist Lars Wilsson found in the 1960s that beavers raised in isolation will show dam-building behavior in response to the sound of running water. This proved to be the case even in the absence of actual water, with sound played over a loudspeaker on a dry floor.
How does that happen?
Well you play the sound of running water and come back to find the building just a big pile of lumber.
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The sound of running water annoys them, basically, and starts up some kind of OCD response. That’s how one wildlife rescue simplified it.
That’s why destroying their dams doesn’t actually solve the beaver problem, if you need an area to have free flowing water for some reason, you essentially have to eliminate the local beaver population, because they’ll come back and block it up no matter how many times they have to do it
That's been the thinking for decades, but a number of devices have been invented in the past 20 years or so to make killing beavers unnecessary in almost all cases. Crucial since they are a keystone species and eliminating them works out poorly in the long run.
The beaver deciever was one brand of device. Its just a covered pipe that bypasses the dam. Neat trick.
Ah yes, ever since the invention of the beaver-deciever there's no more need for the beaver-cleaver.
I used to be annoyed by them locking up streams, but learning about them has made me into a beaver-believer.
A belieber? Like anne frank?
Though the Beaver Cleaver was historically used by Shiva and her believers the Beaver deceiver would grant a breather to the wood weavers.
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and now we have come to find out that beaver damns were important to combat wildfires so we start to help them build dams again.
You don't necessarily have to kill them, relocation will do just fine if there's a specific waterway you need to keep clear.
You could put little earmuffs on them. It would drive the tourists wild, too.
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It was like damn I need to build a dam so I stop hearing that damn noise.
Also, the principle of Emergent Behavior. In any complex system, once that system reaches a critical point, then simple, unrelated steps in the process can combine to create an unexpected outcome, usually not predicted from the relatively unsophisticated inputs. I.e. beavers gnaw trees while eating, trees fall, piles of fallen branches create shelter from predators, populations that survive pass tree gnawing habits to the next generation, etc.
Ahh, Emergent Behavior. One of the most beautiful and fascinating characteristics of our physical universe and barely anyone knows about it
FYI beavers don't eat trees. The actually eat soft vegetation.
If it were emergent behavior it would be to keep their teeth short... since they dont' stop growing but you have more a chicken and egg problem there than a nice happy emergent behavior example.
Don't nearly all rodents have the teeth issue? So it would be reasonable to assume that the teeth growing/gnawing came way before dam building behavior.
Withing the context of emergent behavior theory that would be a valid conclusion I think.... I'm a creationist myself so I have different ideas but, as I said in the earlier comment it would probably be some gnawing behavior due to teeth (but that gets into the discussion of did long growing teeth or gnawing occur first etc.. if you aren't a creationist anyway).
Also I believe rodents aren't the only genus to have long growing teeth or tusks that are maintained by wear and instinct. (which implies potential for parallel evolution or design)
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Same way caterpillars develop "eyes" on their back to scare off predators. Thousands of years of evolution.
The same reason most apes species are scared of snakes by default. The simplest way to explain it is that apes that have a trait that makes them scared of snakes tend to survive longer and reproduce more, therefore spreading the trait that makes apes scared of snakes.
This has actually been debunked. Monkeys raised in labs are not instinctively afraid of snakes.
Turns out you're right study link. The point still stands as an example of evolution, traits that survive natural selection reproduce more, therefore, passing the trait to the next generation.
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Beavers hear a river flowing and think to themselves “absolutely not” then they pile up sticks until that annoying sound is gone
> This proved to be the case even in the absence of actual water, with sound played over a loudspeaker on a dry floor.
Situations like this are always interesting to me because it shows that non-humans don't really...think the same way we do. Which is obvious, but this behavior animals often exhibit, where they will blindly do something in response to a stimulus even though it makes zero sense, makes them look far more like non-sentient robots than actually sentient beings that think like we do.
I mean, I get aroused by pictures of naked ladies and masturbate. That doesn’t really make much “sense” if sex is for procreation. Not really much different than building a dam where there’s no water.
Yeah but you’re capable of fully understanding the mechanisms that cause that response and even know specifically why you’re doing it in the moment. You’re also capable of reflecting back and feeling shame/pride whatever. Most animals can’t even recognize their own reflection
That understanding is a superficial product of our intellect. We’re still operating on the same sort of basic genetic logic.
Put 100 people in a small room and yell fire. Announce pandemic and suggest the toilet paper might run out.
Et cetera.
The comfort our intellect provides us allows us to separate ourselves from the obvious programming that we operate on. Remove that comfort and we return to the base program.
I mean, there's been many times when I've masturbated and had no idea why.
Except it does. Sex is for pleasure. Knowledge of procreation isn't intuitive, we and most other higher order animals do it because it feels good with the reproduction as a side-effect. This is why you see homosexuality and masturbation in a whole slew of animal families where if it was purely for reproductive purposes, you wouldn't.
Granted, this doesn't disprove your argument at all. :P Just a fun point of order.
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Ye, no, sorry to burst your bubble, but that's just 'any biological lifeform', and it does include humans.
We, like any other animals, have a lot of instincts that don't make much sense in our modern lifestyle, or can even be actively counterproductive. I.e. Arachnophobia (or most fears, really). Herd mentality can likewise cause humans to behave hilarious; There's been experiments showcasing this, such as placing some actors in an elevator, back-facing the entrance. Any other person that entered would join them in staring at the back side of the elevator, regardless of the fact that was highly impractical for using that elevator, and utterly pointless. But it's simply instinct to imitate what other humans are doing, even if the action doesn't make any rational sense (instead of, as would be proper, to question whether there is an actual reason for performing that action).
There's also a lot of less-clear examples of instinctive behaviors screwing with us: i.e. over-patternization; Our brains developed two ways to deal with situations: The first is active analysis, which is high in energy-cost, but allows us to make complex deductions. The other is passive repetition, which is extremely quick and energy-efficient, but can only do what we have already established. I.e. driving/riding to work/school on autopilot. It's a neat trick by which we can combine high intelligence with moderated energy consumption. But it also generates a problem, in that the brain will try to aggressively patternize EVERYTHING, in order to turn it into a low-level automated behavior. This means you brain will actively try to class, stereotype, simplify, automate everything it can. Which can lead to, as implied, unjustified stereotypes or in fact oversimplifying problems. This again is a cornerstone of Populism, which tries to stimulate the brain of listeners into simplifying complex societal problems into seemingly simple (but factually incorrect) answers.
So, from these examples alone: Don't, for one second, believe that we humans aren't also animals with very daft instincts. The only thing that differentiates us from most (not even all) animals, is that our consciousnesses have developed to a point where we can (not 'always will') actively recognize when an instinct is kicking in, and might be even able to actively suppress it in favor of a cognitive choice.
I've been trying to dig into what we understand about consciousness from a scientific perspective (turns out it's not much) but one conclusion I drew looking on history is that science inherited the religious bias that humans are special. One thing that appalled me was how long veterinarians in the US were taught that dogs don't require anesthesia as their reactions are purely reflexes, they cannot experience pain (I'm paraphrasing, but the gist of it is correct). This lasted into the nineties IIRC.
In denying other conscious life forms their consciousness, we have also stunted our understanding of it.
> In denying other conscious life forms their consciousness, we have also stunted our understanding of it.
Word.
It's not going to be easy to clearly define (if ever possible) what kind (or even individual!) of animal contains what level of consciousness, but the very least we can do is recognize that it's not a binary toggle, and that we're far from alone on one side. Heck, for all we know we might not even be the extreme of the scale.
I'm hoping we can figure this out, at least partially, before true sentient AI comes into play.
This is what really intrigues me, because when I was looking into physics and consciousness I realized that there's nothing in currently understood physics that prevents consciousness to be the fundamental nature of the universe, rather than emerging from matter.
If that is true, then I'd wager you need biological components when creating a sentient AI (or technology that today is indistinguishable from magic).
If so, yes. That's a pretty big if tho. Might be why decoding whale / orca language could be the next big step in AI development: Being able to communicate with other beings that may be sapient (aka holding consciousness) as well is going to be the only way in which we might be able to truly understand what common denominators constitute consciousness... only then would we be able to replicate it artificially (unless we succeed at that by accident).
Ostensibly maladaptive habits that lead to depression are better examples than populism. You can be convinced to discard a populist worldview with some books or some critical thinking.
By contrast, no amount of reading or high level thinking is going to make your brain not instinctively interpret social rejection as pain and aggressively react and plan against it.
What study I found even more weird is when participants in a study were identifying the lengths of line segments relative to other segments. This one’s longer, that one’s shorter, etc. But, only one participant would be in the experiment. The fake participants unanimously identify a line that is shorter than another as longer and the real participant would agree even though the statement was obviously wrong. So afraid of being different.
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I suspect we have a lot instinctual behaviours that don't make much sense either when examined from a logical perspective. Social/antagonist behaviours come to mind as an area where we probably do a lot of things because of instinctual conditioning.
Even something as the mammalian dive reflex is an instinctual physical reaction.
You beat me to saying the same thing. A big instinct for humans is the ability to learn language. Yes we have to develop the ability as we grow but I bet beavers also get better at building dams with experience
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What do you mean? Humans do similar. Dams just aren't our thing
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Oh, honey. Humans are just as susceptible to those mechanics as the rest.
It’s essentially sentience vs sapience. The beavers are sentient because they can sense and perceive their environment. This information input then over time leads to the damn building behavior because it creates a selection pressure where beavers who build dams survive and reproduce more.
In a lot of ways you could look at our own sapience as the same as beaver dam building behavior. Pattern recognition likely allowed us to develop sapience by giving us the ability to make predictions about the future based of previous information. Overtime this could have allowed us to be able to create models of or environment that do not correspond with our current environment (imagination). At some point in the process sapience arose. This, for obvious reasons, turned out to be an extraordinarily advantages trait for almost any environment. So our ancestors with these traits survived more easily and passed those traits on.
As some people will likely attest, we sometimes blindly think about things for no reason. Thinking is our dam building behavior in a way.
Short counter-argument:
When infected with rabies, a human will flinch and try to move away from water or push it away as soon as the water is close to their mouth! So no, human behavior too can be "automatic" or "manipulated".
(You can find a real video on wikipedia if you wanna see the behavior for yourself...)
I actually think this picture provides an example of instincts in humans: https://www.instagram.com/p/CNUKYnFgkdZ/?igshid=YmMyMTA2M2Y= p
Many predators have forward facing eyes, and on first glance, when it looks like the ant's antennae are forward-faci g eyes, the picture looks like a spooky gremlin and it makes people uncomfortable. When you realize the ants eyes are actually further back on the side of its head, its a relief and the picture doesnt feel as uncomfortable.
Animals (at least mamals) thinks in exact same way, and we do things instinctively same way as them. We are just litlle bit better with thinking and thus less reliable on instincts in most of our life.
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That is, they go through the motions of dam-building, even without materials available. Sort of like beaver mimes.
When they take a speaker making the sound of running water and put it in the forest known to have beavers they will come from far and wide to cover it with sticks until it either stops or becomes muffled enough they can’t hear it
Yes, they will start making dams around the house and it’s whatever they can find
An orphaned beaver raised indoors was just shown on TikTok. It had a pile of short branches it was piling up in the door way. Pretty compelling
I just saw this beaver on Instagram today! He’s just making a random dam inside the house of the rescue person, really cute and so fascinating that this is just instinctual behavior. Kind of like if you have a herding breed dog, it often will try to “herd” people, other pets, etc. without ever being shown how to do it.
Isn't that just great! Happy as can be.
You are also right about a herding dog. Australian shepard as an example can be taken from mother after 6 to 8 weeks. To "training" be that time from mother. 3 months later you have a bunch of children at a birthday party, that pup will be a pro at moving all the kids to a corner!! Good example
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I read of an experiment where beavers started to build dams even when there was no water around but scientists played river sounds over a speaker
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Here's a link I bookmarked on that topic some while ago:
https://www.mentalfloss.com/article/67662/sound-running-water-puts-beavers-mood-build
You can make beavers build a dam by setting up a speaker to play water flowing sounds
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Saw a video on IG or FB the other day of a rescued baby beaver. When it got a bit older it started "damning" towels on it's own, as it was in a house. The behavior was innate though.
That’s still wild to me. How do genes encode information on how to do something? Do they just make the activity enjoyable?
Natural selection via reproduction of genetic material. A group of mammals that carried this gene that coded for this response to running water reproduced and passed on this gene (along with the rest of their genetic material). “Beavers” eventually evolved. It’s important to not view their existence in isolation from other dam-building mammals. Although their behaviour seems peculiar now, other mammals will have done it in the past. That beavers do it now is simply because animals that did it in the past passed the gene down successfully.
Evidence suggests beavers don’t build dams because they enjoy it, but because running water precipitates the influx of potential predators in their environments. Big pike eat baby beavers for example. If there are pike around, there are probably other fish around too, and if there are lots of fish around, there are probably bears and wolves not far away either - which are apex predators in the beaver’s ecosystem. Dam-building is therefore an auditory response to running water that contributes to the survival of the species carrying the gene that codes for it.
Dam-building helped animals carrying the gene for it to survive. Beavers are around now because the genes responsible for building dams have helped them survive. If a group of beavers were forced out of their aquatic environments, the genes coding for this behaviour would become less and less useful to their offspring, and their offspring’s offspring, ad infinitum. Different genes would become more useful to this group. This is a very rudimentary explanation about how speciation occurs. Speciation involves the interactions between animals’ genetic material and their environments. Those best adapted to their environments survive to pass their own genes on. Thanks Darwin!
Why and how there has actually come about genetic material that causes a response in animals to running water that makes them build dams, I have no idea. I suspect it is not genetic material too dissimilar from that which incites birds to build nests, or even that provokes humans to build shelters
"Evidence suggests beavers don’t build dams because they enjoy it, but because running water precipitates the influx of potential predators in their environments."
Those things aren't mutually exclusive. Is there really evidence beavers don't enjoy building dams? Because that sounds like saying, "Humans don't eat because they enjoy it, they eat because they need food to survive." When in fact we eat because we enjoy it, and we enjoy it because any people who didn't like eating would have died out.
Yeh you’re right. Maybe they do enjoy building dams - i don’t know. But there’s certainly a reason for it beyond enjoyment alone
Also raising the level of the body of water is a co-shebang. That can extend their territory considerably.
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The pond is also used as food storage. During the winter beaver will east the cambium off the submerged tree branches. That's why you'll see large immovable tree felled into the pond, it's food storage not dam material.
Beavers are also caecotrophy (nsfw)
Actually, recent research has show that they build dams to stop the SOUND of running water. When a speaker playing that sound was put near beavers, the piled wood on top of it until it couldn't be heard.
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And why do they need to dam, is it because they need flowing water for health? Else a lake would seem like the right source. Maybe they just like a clean toilet.
Also it is triggered by the sound of running water. Captive beavers will start to make a dam if they hear a recording of running water.
Also to trap fish in that pond, no?
Beavers are rodents, like mice and rats, and as such are herbivores. They might eat an occasional insect or similar, like squirrels do, but they don't hunt.
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Tbf mice and rats are not great comparisons, those guys will eat anything including each other given half a chance. Rabbits and voles maybe?
No Beavers stash leafy branches underwater to munch on. However their ponds do tend to accommodate fish as well and so often otters and other fish eaters will use the ponds as well.
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Beavers build dams in response to the sound of running water. It’s an instinctual response that they will have regardless of upbringing. At least according to this article.
I’m Dutch and we also have this instinctual urge to build dams when we hear running water.
The Dutch are, on average, the tallest people in the world. This is because anyone too short drowned eons ago
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There is such a beauty in the behavior that makes at least a small part of the drive so humanly relatable. Though imperfect, I just like to think that running water creates anxiety and they soothe it by applying the necessary amount of sticks.
You make it sound so peaceful. Fuckers will rebuild that dam overnight like ocd with cocaine.
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Here's an interesting recent video of an orphaned beaver. Though not scientific, the damn building behavior along with the possible soothing, comforting, and pleasant feelings the behavior may provide appears to be caught in this video. Behaviorists are contacting her and who knows, perhaps they will discover new understandings of these drives. :)
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Actually the correct answer is that it's both. Beavers ALSO have a cultural component to damn-building. Beaver families learn to build different ways, which passes on "localized" or unique build patterns to the offspring. This is similar to how bears in particular parks have learned to open bear-proof jars through practice and observation. Basically, we knows beavers also have localized culture because they pass on (ineffective or specific) building techniques. Some of the dams beavers build are really awful, no lie.
Funny that this is the only correct answer in the thread. The beaver's instinct is to dam-build, yes, but they don't make anything good with the instinct alone, it has to be honed by their family teaching them.
The localized culture information is new to me, can you share a source so I can learn more about it? Thank you for the explanation 🙂
I cant find it! I wish I could. I found some more generic articles about how beavers work, but not including behavioral analysis of the parenting tactics. Within any animal culture (including humans), the way we teach skills will contain some localized techniques. There have been more specific studies done with this in bear populations.
https://www.beaversolutions.com/beaver-facts-education/beaver-behavior-and-biology/
http://resp.llas.ac.cn/C666/handle/2XK7JSWQ/213152 Interesting ties between beavers and climate change
I'm picturing bears taking notes from afar on how humans open the bear-proof containers.
That would be so cute. My favorite quote from the park rangers at Yosemite is, "There is considerable overlap in the intelligence of the smartest animals and the dumbest humans."
The answer to the second question about evolution is easy: Beavers have an insanely successful strategy for avoiding predators. Before humans wiped them out, they were ubiquitous, even in areas like Nevada and Arizona, which are considered deserts now.
It is estimated that there were 200 million beavers in North America alone a few centuries ago.
Some people said some things so I will add. Safety, beavers enjoy steams and pond usually smaller than ones sturgeons live in. Past that they have no aquatic predators. Big ponds keep the wolves and cyotes further away.
Some said underwater entrance.
Another is winter rafts. They will construct piles of wood so that fresh twigs and leaves are below the surface before winter. So along with digging for roots and hibernating fish they can enjoy fresh sticks and leaves. A larger pond means more access to submerged food sources, their preference.
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If anyone is interested in more on this, I think this is an example of what is called an extended phenotype. A phenotype is the expression of a genotype (gene), such as hair color. "Extended" means to something like this, i.e. birds that build a certain type of nest that comes from a genotype.
Richard Dawkins wrote a book called "the extended phenotype" about this, if anyone cares to learn more.
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We ask these questions because humans are one of the very few animal species that has to learn all of their basic survival skills from the previous generations. It’s a problem because our heads are than our body at birth in order to actually fit through the pelvis to be birthed, and they have to grow as we age. The hard coding of our brain to do the things we need to just aren’t there, but as an added side effect, it does give us more individuality and the ability to grow our intellect more so than any other animal
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Splatulance t1_it4k8ny wrote
Genetically coded.
They build dams instinctively to create a pond/lake which they then construct a nest (lodge) in. The nest has an underwater entrance, which keeps predators out. The point of the whole shebang is that underwater entrance.