Barometric moulting

[DrAce]

For my first go round with this data collection I am going to use the KISS method. "Keep It Simple Stupid."
I am not calling anyone stupid, I am just saying I know there are a billion different variables that could go into this, but for now I am going to see if there is any correlation between barometric pressure and Ts molting, and if so is there a significant pressure drop or a minor one.

A wise move! I'm just thinking ahead of the data, and anticipating what questions would then be raised. I don't think these things need to be teased out in the same omni-cognizant experiment (athough they could).

Might artificially altering pressure induce a moult?

 

[Talkenlate04]

Well Cacoseraph, Looks like I am going to need maybe a 365 day data sheet of some sort. With the ability to track more the one persons data.
This wont muddy the overall data collection so long as we are all doing what we can to get the correct info.

 

[Talkenlate04]

So Drace, there has been someone from IN and IL both reporting multiple molts over last night........ and a High pressure moved out of that area yesterday afternoon and late last night. Now that we have more then just ourselves making these observations this will start to sound more plausible as we go on.

 

[cacoseraph]

ok, i see two kind of fundamentally different ways of going about this

of course one method would probably be better science... but ghastly amounts of work and the other method... well... i'm not really sure what it will prove, if anything

anyhow, difficult method = record pressure every hour, few hours, 6 hours, or day at worst. whatever schedule you pick, you need to measure at the same time every day. when a spider molts you match the molt time to the barometric time closest. the more time points you take pressure readings at the better (like, every hour would be best by far).

easier method = only take a pressure reading when a spider molts



the harder method will allow for a like, negative proofs, i *think*. in other words if there are a bunch of low pressure times with no molts that would lower the corellation... i am not exactly sure how to wrangle that data though, at this time

the easier method would allow for an easier like, false positive. i think.


i hope to dog ace knows what i mean and can make it more clear.


actually the ghastly one might not be *that* bad... you might not have to record pressure readings yourself. you might beable to get a data dump from some weather type website... or school or government. then we can do the interpolation thing. i should be able to make a little formula for linear interpolation. i think.

 

[Talkenlate04]

I have local weather sites that have proven to be fairly accurate. So instead of monitoring every whenever you said, which sounded like a boatload of work, we can refer to the data that is recorded by someone else. Like I have said I just want to see if there is a cause and effect going on here. If there is a reason to continue thinking along these lines when we are done, then we can repeat and work to prove.

 

[cacoseraph]

I have local weather sites that have proven to be fairly accurate. So instead of monitoring every whenever you said, which sounded like a boatload of work, we can refer to the data that is recorded by someone else. Like I have said I just want to see if there is a cause and effect going on here. If there is a reason to continue thinking along these lines when we are done, then we can repeat and work to prove.

i think the next step would be for you to check to see what kind of datadumps you can get. once you find that out making a spreadsheet tailored to them should be much easier

 

[DrAce]

So Drace, there has been someone from IN and IL both reporting multiple molts over last night........ and a High pressure moved out of that area yesterday afternoon and late last night. Now that we have more then just ourselves making these observations this will start to sound more plausible as we go on.

Just cos everyone else sees it doesn't make it right. You know that as well as I do. I know people who have seen the virgin mary in a piece of toast. Didn't make it right.

I completely agree, it's a likely hypothesis. But having a nice hypothesis and TESTING it are two different things. Is it the drop in pressure you think causes what you are seeing, or the increase in pressure which preceeded it? And you still haven't discounted some small humidity or temperature change. These would likely be consistant between the two storm fronts you have spotted. Two multiple moults in two areas do not a hypothesis prove. Were there any multiple moults in an area without a storm? Maybe there were a whole Bunch of Brachies in the desert somewhere which all moulted but no-one was there to watch.

 

[Talkenlate04]

There does not have to be a "storm" high pressure and low pressure fronts are moving all the time. Some don’t have a huge climate effect.

People seeing it counts toward the hypothesis it just adds to the fact that this might be worth getting deep into. Its easy data to collect at this point because of the limits I have set for the first go round. If people have molts and check their weather and see a front came through and the pressure changed, that just strengthens the hypothesis. Their observations will not be added to this collection, but its still good to know.

And this first leg of data will just help ether kill the idea by strongly proving there is no direct connection at all, or prove its worth the effort to continue.

 

[DrAce]

There does not have to be a "storm" high pressure and low pressure fronts are moving all the time. Some don’t have a huge climate effect.

People seeing it counts toward the hypothesis it just adds to the fact that this might be worth getting deep into. Its easy data to collect at this point because of the limits I have set for the first go round. If people have molts and check their weather and see a front came through and the pressure changed, that just strengthens the hypothesis. Their observations will not be added to this collection, but its still good to know.

And this first leg of data will just help ether kill the idea by strongly proving there is no direct connection at all, or prove its worth the effort to continue.

I am aware of all this. You posted a rather reactive comment above, and I bit the bait and took it to pieces (I'm having little success in the lab at the moment, and may have vented... sorry).

As I mentioned several posts above, I think this is (as many of your observations) a really good idea, and worthy of persuing. Again, I offer any help I can, as Cacoseraph has. But I also philosophically and scientifically refute your comment that "People seeing it counts toward the hypothesis it just adds to the fact that this might be worth getting deep into.". This is wrong. It turns the scientific method on it's head. A set of observations lead to the hypothesis. Further observations do not verify the hypothesis - testing does. A true and fair test of this phenomenon would be to artificially alter the pressure in the tarantula enclosure (I can think of a couple of ways of doing this - but none are particularly easy. Things like rubber sealed enclosures with air-pumps... complicated and fiddly). These are not immediately available, so you're collecting other data. That's cool and fine.

What I post above is a good, sceptical pick at the anticipated results. If you do find a correlation between storm fronts or barometric pressure, you would NOT have excluded any humidity or temperature effects. That's not a pick or anything personal - it's a realistic hole in the method. Again, nothing wrong with that - but it's looming on the horizon if you chose the method that you are chosing.

And I would chose the method that you are chosing. But you should anticipate any criticisms that might arise, and have a good way of testing them. That's how these things get sorted.

 

[cacoseraph]

I am aware of all this. You posted a rather reactive comment above, and I bit the bait and took it to pieces (I'm having little success in the lab at the moment, and may have vented... sorry).

As I mentioned several posts above, I think this is (as many of your observations) a really good idea, and worthy of persuing. Again, I offer any help I can, as Cacoseraph has. But I also philosophically and scientifically refute your comment that "People seeing it counts toward the hypothesis it just adds to the fact that this might be worth getting deep into.". This is wrong. It turns the scientific method on it's head. A set of observations lead to the hypothesis. Further observations do not verify the hypothesis - testing does. A true and fair test of this phenomenon would be to artificially alter the pressure in the tarantula enclosure (I can think of a couple of ways of doing this - but none are particularly easy. Things like rubber sealed enclosures with air-pumps... complicated and fiddly). These are not immediately available, so you're collecting other data. That's cool and fine.

What I post above is a good, sceptical pick at the anticipated results. If you do find a correlation between storm fronts or barometric pressure, you would NOT have excluded any humidity or temperature effects. That's not a pick or anything personal - it's a realistic hole in the method. Again, nothing wrong with that - but it's looming on the horizon if you chose the method that you are chosing.

And I would chose the method that you are chosing. But you should anticipate any criticisms that might arise, and have a good way of testing them. That's how these things get sorted.

post hoc ergo propter hoc and correlation is not causation. two biggest problems in er, scientific logic. KILLERS to train yourself to avoid... and still so terribly easy to fall prey to them. for sure.

 

[dianedfisher]

Dr. Ace, I keep my T's in a spider cabinet, no lighting and temperature regulated at 77-79F. Ambient lighting in that room is minor, so light and temps are pretty stable. Humidity is regulated by a humidifier byt that is on a timer and s subjec to change with room humidity changes.

Talkenlate: So. In is nice this time of year and not too bad the rest of the year. India"noplace" is just somewhere we visit when we need to do official "state" stuff. I prefer St. Louis and Nashville for fun things.

With regard to the barometric pressure idea: I will gladly keep track of my small group of T's and relay info as it becomes available. I'm not sure about recording "hourly" weather data but I believe that data is available on the net if it is required. I have a P. scrofa who nees to molt badly and the eather front certainly didn't encourage HER to put on some new clothes. Di

 

[tarantulas.com]

Yes, Dan from Tarantulas.com brought it up to me about 6 months back, and ever since then I went back and looked at weather data in my area the dates I had molts and egg sacs and his theory is holding up pretty well, very well actually. Every molt I have had has occured when a front was coming through and the pressure decreasing. I had three molts yesterday, and in Oregon we had high pressure move away to the east starting mid morning yesterday.
I think it's pretty interesting. I am going to continue with trying to check on how much of a pressure drop there is to see if that makes any difference. The cool part is all this data is recorded by someone else so if you miss a day you can find it somewhere.

I believe my original statement was relating to eggsac construction. I do agree that the molting cycle is long and complex, and therefore may not be directly related to changes in pressure.
It does seem to me that I have higher volumes of sacs laid during rainstorms. Of course, I also have them laid when there are no strong weather systems. I do suspect some correlation, because I often have multiple sacs laid on rainy nights. Last Saturday it rained hard at night, and two versicolor laid that night. One female was only bred 5/9/2007, the other was bred 7/06/2006!
All of us that breed spiders should have the eggsac dates recorded, we also should be able to combine that data with barometric data fairly easily (30 min to 3-4 hours of work.) Maybe someone (who loves spreadsheets), would like to petition members for this data.

 

[cacoseraph]

I believe my original statement was relating to eggsac construction. I do agree that the molting cycle is long and complex, and therefore may not be directly related to changes in pressure.
It does seem to me that I have higher volumes of sacs laid during rainstorms. Of course, I also have them laid when there are no strong weather systems. I do suspect some correlation, because I often have multiple sacs laid on rainy nights. Last Saturday it rained hard at night, and two versicolor laid that night. One female was only bred 5/9/2007, the other was bred 7/06/2006!
All of us that breed spiders should have the eggsac dates recorded, we also should be able to combine that data with barometric data fairly easily (30 min to 3-4 hours of work.) Maybe someone (who loves spreadsheets), would like to petition members for this data.

that spreadsheet lover could probably glean some from the breeding reports, too and then seek out barometric data

ah man, this might be kind of a lot work. would be worth it though if we can push correlation to causation and then optimization

edit:

two things:

1) i forgot to say "dirty spreadsheet lovers!"

2) we MASSIVELY hijacked the baromolting thread. maybe we should have a mold split into "Barometric affects on eggsac production" or something liek that?

 

[DrAce]

Dr. Ace, I keep my T's in a spider cabinet, no lighting and temperature regulated at 77-79F. Ambient lighting in that room is minor, so light and temps are pretty stable. Humidity is regulated by a humidifier byt that is on a timer and s subjec to change with room humidity changes.

Talkenlate: So. In is nice this time of year and not too bad the rest of the year. India"noplace" is just somewhere we visit when we need to do official "state" stuff. I prefer St. Louis and Nashville for fun things.

With regard to the barometric pressure idea: I will gladly keep track of my small group of T's and relay info as it becomes available. I'm not sure about recording "hourly" weather data but I believe that data is available on the net if it is required. I have a P. scrofa who nees to molt badly and the eather front certainly didn't encourage HER to put on some new clothes. Di

Di,

You've made a really good effort to annul any potential alternative effects, and you are doing exactly what you need to do. What I was immediately referring to above was talkens comments. Ultimately the point being made is that a storm front is not just a pressure effect.

The best and only true effect would be to be able to induce a moult by altering the atmospheric pressure in the tarantula environment.

 

[138]

would moon cycles also affect egg sacs? and i can also provide molt dates and weather from my area if needed. my T room is also at a stable 76-80 most of the year.

 

[DrAce]

would moon cycles also affect egg sacs? and i can also provide molt dates and weather from my area if needed. my T room is also at a stable 76-80 most of the year.

If they are isolated from the light or effects of the moon, then I doubt it. There are stacks of things that are affected by the moon, however. Male and female hormone cycles are one of them.

 

[Talkenlate04]

I believe my original statement was relating to eggsac construction. I do agree that the molting cycle is long and complex, and therefore may not be directly related to changes in pressure.
It does seem to me that I have higher volumes of sacs laid during rainstorms. Of course, I also have them laid when there are no strong weather systems. I do suspect some correlation, because I often have multiple sacs laid on rainy nights. Last Saturday it rained hard at night, and two versicolor laid that night. One female was only bred 5/9/2007, the other was bred 7/06/2006!
All of us that breed spiders should have the eggsac dates recorded, we also should be able to combine that data with barometric data fairly easily (30 min to 3-4 hours of work.) Maybe someone (who loves spreadsheets), would like to petition members for this data.

Ahhh man sorry for mis quoting you :wall:

 

[Nitibus]

Just a heads up : My last 5 moults ( slings ) have all happened between 101.44 kPa and 101.15 kPa. Only one moult happened while barometric pressure was on the rise.

Anyone find anything else yet ?

 

[Talkenlate04]

I have had now 5 egg sacs, 4 constructed at a pressure oh 30.06, and 1 at 30.07.
To me that was very interesting. Proves nothing but still was interesting to notice they were all so close together in pressure.
And all my molts seem to be happening when the pressure is down. I have yet to see one occur when the pressure was on the rise.