A calm baboon

[Code Monkey]

There are a range of predictable behaviors that we know tarantulas will display (they're not going to suddenly begin singing and dancing the Macarena, for example). However, when they display these behaviors is not predictable.

<devil's advocate moment>
Depending on how you want to look at it, this could be seen as being wholely predictable. Not saying that is what DP had in mind, but I generally would consider Ts to be extremely predictable even though I agree 100% with the above statement. I know I'm going to get behaviour A, B, or C and I've got a feel for the probabilities of each; that is predictability of a kind, particularly since the range of possible behaviours is so limited.
</devil's advocate>

 

[Dr Pies]

They respond to stimuli in their environment with instinct, not with higher-level thinking skills.

Which proves the point. With experience you can predict their movements on the stimulus you provide to them. If one day the tarantula decides to attack rather than run for cover, something is being done different to provoke a different reaction. You give tarantulas far too much credit in their thinking capacity.

 

[Code Monkey]

Which proves the point. With experience you can predict their movements on the stimulus you provide to them. If one day the tarantula decides to attack rather than run for cover, something is being done different to provoke a different reaction. You give tarantulas far too much credit in their thinking capacity.

And you oversimplify what is limited but not 1+1=2. Invertebrate responses are largely controlled by an additive process of stimulatory and inhibitory nerve impulses, unless you can control for every bit of input that might be taking place, it adds a "random" element you can't account for.

 

[becca81]

<devil's advocate moment>
Depending on how you want to look at it, this could be seen as being wholely predictable. Not saying that is what DP had in mind, but I generally would consider Ts to be extremely predictable even though I agree 100% with the above statement. I know I'm going to get behaviour A, B, or C and I've got a feel for the probabilities of each; that is predictability of a kind, particularly since the range of possible behaviours is so limited.
</devil's advocate>

Yes, knowing the probabilities of the behavior happening is a kind of predictability. However, in the context of someone patting their P. murinus on the rump, I feel that it's fair to say that the response to that action is unpredictable. I feel that it's most likely that the spider will exhibit some sort of defense mechanism. However, one can't predict when this will happen (in this case, since the spider does not seem to be displaying stereotypical behaviors) due to the fact that we don't know the level of the perceived threat.

Since the range of possible behaviors is so limited, then of course the predictability of a tarantula's behaviors would be higher than that of an organism with a much larger range of behaviors (without getting into the statistics of any one behavior).

My main point in the initial post was that touching a spider in the described way (particulary the given species) was a risky decision because the person could not be assured that the spider would respond the same way each time it was touched.

To varying degrees, virtually everything is predictable.

 

[becca81]

Which proves the point. With experience you can predict their movements on the stimulus you provide to them. If one day the tarantula decides to attack rather than run for cover, something is being done different to provoke a different reaction. You give tarantulas far too much credit in their thinking capacity.

I'm giving them very little credit - as stating that they are responding instinctually to their environment - not using higher thinking skills to respond.

We don't necessarily know what the difference is when a tarantula changes its behavior - there are variables that we are unaware of or have no control over.

 

[king7]

nice OBT

mine is really really agresive

 

[Code Monkey]

Yes, knowing the probabilities of the behavior happening is a kind of predictability. However, in the context of someone patting their P. murinus on the rump, I feel that it's fair to say that the response to that action is unpredictable.

Fair enough, and this would be why I don't pat any of my spiders on the rump except to get the usual "move along" response when goading them where I want them to go (and using a paint brush for those times you do get the "reach around" )