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How to Speak Cicada

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Re: How to Speak Cicada

#12

Post by jrochkind1 »

nkrisc wrote: post #7
hnbad wrote: post #4

Earlier quoted context omitted.

Realistically, what more do you need?

Perfectly sufficient for this last stage of their life where they do two things: mate and die.

As opposed to the first stage of their life where they do only one thing, suck on tree roots.

Re: How to Speak Cicada

#14

Post by wycy »

keithnz wrote: post #6

be great if we find the "shhhhh! everyone be quiet there are predators around, lets go somewhere else".

There might not be one. Cicadas seem to have almost no predator avoidance instincts whatsoever. Wikipedia describes their survival method as "predator satiation"--that is, emerge in such tremendous numbers that it doesn't even matter how many of them get eaten.

Re: How to Speak Cicada

#16

Post by benstrumental »

dspillett wrote: post #8
qwertox wrote: post #3

Found a good PBS video on YouTube https://www.youtube.com/watch?v=W_fy2vCcIiE So they spend 17 years underground, then get out, mate, and then die after around 4 weeks.

For some groups it is 13 years. It is thought that the co-prime-ness of 17 & 13 (all primes are co-prime, as are many combinations of non-primes, so these two numbers are not especially special in that sense) helps reduce competition for resources between those with the different periods. Nature doing its clever but simple solutions thing.

What resources would they be competing for? I would expect more overlapping years would be beneficial since their primary survival strategy is predator satiation.

Re: How to Speak Cicada

#17

Post by moron4hire »

I've got a ton of M. septendecim in my back yard right now. This is the first time I've heard this kind of call and it was definitely kind of creepy at first. A few get on my house in the middle of the night and then you can hear a single individual call. I thought it was a person outside, crying in pain, at first.

One thing nobody talks about is the stink that starts to develop about two weeks after they first start emerging. My backyard is disgusting with decaying cicada bodies. We even had a pretty long rain over the weekend and it's still pretty unbarable out there.

Re: How to Speak Cicada

#18

Post by valarauko »

dspillett wrote: post #8
qwertox wrote: post #3

Found a good PBS video on YouTube https://www.youtube.com/watch?v=W_fy2vCcIiE So they spend 17 years underground, then get out, mate, and then die after around 4 weeks.

For some groups it is 13 years. It is thought that the co-prime-ness of 17 & 13 (all primes are co-prime, as are many combinations of non-primes, so these two numbers are not especially special in that sense) helps reduce competition for resources between those with the different periods. Nature doing its clever but simple solutions thing.

The ranges of the 17 & 13 year Periodic Cicadas don't really overlap, so the strategy isn't to avoid competition with other cicadas. It's believed that the prime number periodicity is to avoid the life cycle periodicity of predators.

Besides, in areas where different cicadas overlap, they spend something like 99.9% of their time underground consuming the same food resource, alongside the non periodic annual cicadas. Competition between cicadas doesn't seem a major issue.

Re: How to Speak Cicada

#20

Post by moron4hire »

jszymborski wrote: post #19

I'm curious, what Cicada songs the people on HN are hearing? I'm in Montreal and I'm pretty sure the ones I hear are Dog Day cicadas (N. canicularis)[0]. [0] https://www.cicadamania.com/cicadas/neotibicen-canicularis-h...

I've definitely got M. Septendecim https://vm.tiktok.com/ZMeTCje3h/
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