tarantulas & ballooning.

[Malhavoc's]

Was browsing the forums when this image came up.

http://www.arachnoboards.com/ab/gallery/showimage.php?i=25293&c=48

This seems to be a very very typical ballooning pose that you would normaly find in true spiders, especialy freshly hatched young, as they await a breeze for take off; I could be mistaken, any one else notice such a behavior in the younger tarantulas.

 

[TsmallV]

hahaha i never saw that before, i think its a threat pose that it is going to shoot poop at you xD
its just a guess

 

[Zman181]

Both my t okertis do this all the time.

 

[toast4nat]

My A. schmidti has done this, I believe it is indeed a threat pose.

 

[Malhavoc's]

I considered this for awhile aswell. However the aboreal fecal matter spraying tarantulas that I have had, never displayed such a posture, it was more well aimed and lower; however I am not the photographer, mearly a think tank the picture inspires I've also never had a Poec, spray me before.

for those not fimiliar with balooning, this video shows it toward the end and you will see the pose I am refering to
http://www.youtube.com/watch?v=aICZqRY3_d4&feature=related
( it also shows some wonderful molting video.)

My A. schmidti has done this, I believe it is indeed a threat pose.

Again A, Schmidti has Urticating hairs, Poecs do not.

 

[jayefbe]

I've seen this quite often in terrestrial species. I imagine that it's meant to dissuade potential predators by appearing larger, although I'm not sure if that's why the trait evolved.

 

[Bill S]

It does resemble the pose of ballooning spiders - but ballooning requires a very small spider and some silk. It's hard to tell exactly how small this individual is, but probably too large to balloon. And I don't see the silk "tail" that a ballooner would produce.

THe one thing we are not seeing here is the natural context in which this display would occur. A lot of threat, camouflage, and other display behaviors are not easily recognizeable when seen in artificial environments.

 

[Zoltan]

I don't think that that specific spider is trying to balloon, but I find it imaginable that theraphosids woud use this method of dispersal. Here's an article about an account of early instar Sphodros (Atypidae) ballooning:

Coyle, F. A. 1983. Aerial dispersal by mygalomorph spiderlings (Araneae, Mygalomorphae). Journal of Arachnology 11: 283–286. [PDF from americanarachnology.org: click here.]

 

[Malhavoc's]

Excellent Zoltan, you as always are the knowledgebase I seek!


As someone said earlier, the larger the spider, the harder it is for it to become airbourne, however; with some mygals having been found to balloon (see Zoltans post) I do wonder if it is not possible, though rare that some of our Tarantulas can and do balloon, even if at a young age. Aboreal species like Avics, I certianly could see doing it.

 

[ZergFront]

I've seen my P.regalis sling do this just before shooting poop. Likely to make sure waste gets far away from the hide as possible. There's a caterpillar that will actually flick it's poop really far away to avoid wasps using it to locate the caterpillar. I wonder if this is a similar strategy or if it's exclusively to keep a clean home.

I'm reading a book called Spider Silk and it says that not many, but a few mygalomorphs do balloon as slings. Doesn't say if any of them are Theraphosidae.

 

[grayzone]

all very good suggestions ... ive only seen this in terrestrial ts, and even with them, its a trait ive witnesses with SLINGS... occasionally my 4-5" female rosie will do this as well... NONE of my arboreals have ever done it, then again i typically cause the least amount of disturbance with my pokies as possible

 

[Tarac]

All my Pamphos do this. I always thought it was a sort of threat too- "watch out, I'm bigger than you thought and I have this really irritating hair on my bum that I'm going to flick in your eyes if you don't back off." I've seen it with adults and slings. Its not just my Pamphos only, but I have not noticed with OW or arboreal species personally. For me, it only happens when they are bothered by something which is why I thought it was probably some type of defensive/offensive posturing.

 

[Formerphobe]

I have observed true spiders adopting that pose early in the mornings. Dew accumulated on their backs during the night would run down and they would drink the droplets that coalesced on the lowest part of their anatomy- their chelicerae, in that stance. Over several hours of observation, they made no effort to 'balloon', and when they were done 'drinking' would go on their merry way in search of prey.

Here is an Aphonopelma species doing something similar. But, different enough that it could mean something completely different than the spider in the first post. The only time I see this mature female doing this is at the entrance to her burrow when she comes out in the evening, and never in relation to any obvious stress. I have wondered if it is a means to 'test' the environment at the burrow opening.

C. ritae sling in similar pose, which I only see when I open the lid to its container. Would seem that in this case it is a threat pose. However, with the influx of 'new air', it, too, could be 'feeling' the changes in its surroundings.

I think the understanding of spider body language is still in its infancy, but extremely fascinating.

 

[Malhavoc's]

A new thought came to mind; could it have something to do with trying to expose the book lungs to dryer/fresher air then what is close to the surface? God, gotta love all the ways our pets like to say "ha you have not figured us out yet!"

 

[Tarac]

I have observed true spiders adopting that pose early in the mornings.

That's interesting. I also wonder if it has anything to do with increasing surface area to help speed up warming in the morning sunlight, which is a behavior exhibited by many inverts like shore or land dwelling crabs and butterflies- the Mourning Cloak (Nymphalis antiopa) opens its very black wings to the early morning sun in order to heat up since it is on the wing so early in the year there is sometimes still snow on the ground.

I've never observed any of my Ts doing this for any other reason than a disturbance though so I'm still sticking with a defensive posture of sorts, at least for Pamphos.

It's also reasonable to think, as you suggested Former, that there may be some other sensory mechanisms at work- "testing" the environment as you put it.

Good question and responses!

Another possibility is that they are secretly auditioning for a rap video and just want us to see how bootylicious they are

 

[ZergFront]

I have observed true spiders adopting that pose early in the mornings. Dew accumulated on their backs during the night would run down and they would drink the droplets that coalesced on the lowest part of their anatomy- their chelicerae, in that stance. Over several hours of observation, they made no effort to 'balloon', and when they were done 'drinking' would go on their merry way in search of prey.

Beetles in the African desert have adopted a similar strategy. They will go on top of dunes in the early morning to collect dew with this odd position. Wish more desert insects from Africa were available. They exhibit some unique survival behaviors like the spider who rolls down dunes to avoid wasps.

 

[Ultum4Spiderz]

Usualy Ts like M robustom do this too look bigger & makes it easier to shoot urticating hairs