

Spider That Builds Its Own Spider Decoys Discovered - thekevinjones
http://www.wired.com/wiredscience/2012/12/spider-building-spider/

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smtf
_“Considering that spiders can already make really impressive geometric
designs with their webs, it’s no surprise that they can take that leap to make
an impressive design with debris and other things,”_

Sure, but what is more interesting is how such a spider would know what itself
looks like.

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6ren
There's no need for the spider to know what itself looks like. If it builds
something that increases survival/reproduction, that trait will be selected
for.

    
    
      The spiders’ webs were crafted around face-height, near the trail
    

This makes me wonder if it was selected for stopping humans from wrecking
their webs! It would explain why the decoys look like spiders, to humans.

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VMG
way too little time to evolve that behavior

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wmblaettler
Could this decoy be used in the mating ritual to attract females rather than
something to do with predators? From my limited reading, many spiders have
rather elaborate mating rituals. Also with females being larger and usually
killing the smaller male spiders, having a decoy to distract the female might
allow the spider to stay alive longer and mate with more female spiders.

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takluyver
I think it's the male that goes to the female in such cases. The decoy could
perhaps be used to attract _males_. But I'm not an arachnologist, so there may
be some obvious reason why that's not the case.

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bogrollben
so seriously, how does behavior like this evolve?

step 1. less-evolved spider builds random clump on web

step 2. spider achieves benefit of scaring off more predators

step 3. spider with clump-building ability becomes dominant species as it
outperforms and outcompetes non-talented spiders

step 4. spider with clump-building ability builds less-random clump

step 5. repeat step 2 thru 4 until spider-like clump achieved

my question with this hypothesis is, why does the clump-building behavior end
up with something that looks like a spider and not something that would give
the spider an even greater evolutionary edge, like say, a tiger's face?

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mediocregopher
I think the benefit might be less of scaring away predators, but just acting
as an alternative, bigger target for them. Anyone looking at spider webs for a
meal will immediately go for the large obvious spider-looking thing in the
web, and while that predator is dealing with the confusion of getting a
mouthful of debris and gunk the real spider can make a get-away.

~~~
bogrollben
good point. but this means that step 1 has to immediately be appetizing to be
of evolutionary benefit. (arguably it could be). It also conflicts a little
bit with the observed behavior that the spider is shaking the web, trying to
get attention to the bigger spider. If the true benefit was escape, I would
think not-attracting attention would be the resultant behavior.

Just my opinion. I guess we don't know for sure. There's probably a way for
some biologist to figure that out for certain - would make an interesting
postdoc.

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bonobo
Step 1 doesn't need to be that appetizing if the cost of building the decoy is
low. Any benefit, as little as it may be, is already an advantage if it covers
that cost.

About the attention-seeking behavior, we can compare it to the same behavior
geckos adopt when they find themselves in danger: they start shaking their
tails vigorously to attract the attention of the predator to the tail (geckos
are known for being able to detach their tails in these cases, and once
detached the tail keep shaking vigorously, potentially attracting the predator
giving the gecko a chance to escape). In both cases, the spider and the gecko
seem to only engage in this behavior once they already have the predator's
attention, so trying to escape without shifting the predator's attention to
the decoy could actually put the attention on them.

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ChuckMcM
Wow, just wow. Not that I'm a big fan of spiders mind you but a spider that
creates 'fake' spiders as decoys? That is pretty amazing. Thanks for sharing
it.

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MatthewPhillips
True hackers. Love it.

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Goranek
Am I the only one who thought the story is about web spiders?

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takluyver
I hope I'm not the only one who read this comment and spent a moment thinking
"but it is!"

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mhb
Another interesting spider - peacock spider:

<http://www.youtube.com/watch?v=9GgAbyYDFeg>

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hfsktr
The first half was great but the narration was not very good towards the end.

I finished it though because it was fascinating. Reminds me of the birds that
have elaborate rituals and when I think of the bug versions they are much less
exciting. The spider was 'almost' cute but then I saw some of the other
suggested videos and remembered why I don't like them.

What's amazing is there are probably many species of bugs just waiting to be
found.

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return0
It seems like spider weaving is such a natural and central ability to spiders.
What's more it's hackable. Some wasps inject chemicals that manipulate them to
create a habitat for their eggs and be even eaten alive.

<http://en.wikipedia.org/wiki/Hymenoepimecis_argyraphaga>

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lampe
the questions is how does he know how he looks like? is he looking at other
spiders? maybe he looked into a reflection on the water? or does he simply
just know?

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jeffool
Don't all animals "know" to some degree? After all, they "know" they're
attracted to mates of the same type. Though I guess sometimes a dog humps a
leg.

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FarhadG
Even they're cloning themselves? I think we're falling behind in the race

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phirschybar
pretty amazing that they can make something to scare the big guys while
catching the small guys. also prevent the bigger guys from ruining the trap.

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benwerd
I'd love it if ducks did this.

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Hussem22q
Maybe spiders see themselves through offsprings.

