Hi guys. Sorry, I've been sick and without internet access for two days !
@UncleCharlie
Good point raised !
I only realised after you asked the question that I had assumed that they were "full arboreal" because all the information about habitats mentioned "dedicious and tropical forests" - so i just assumed they were arboreal :igiveup:
With more checking up, and as the others have mentioned, turns out that although they primarily build their burrows on the ground and bases of trees/plants, they can and do build web burrows in trees.
Most information however, points to them being primarily terrestrial burrowers.
So looks like even that behaviour can be varied in individuals of the same species.
DISCLAIMER :
I ain't no biologist or nuthin' so my information and supposition is based on research and educated theorising.
Some of this may be nonsense, so Experts, please feel free to correct me and teach us all !
Environmental Notes :
To head off a bit into Theoretical Land, I'll hazard a guess that certain species of tarantula (like many other lifeforms) are better evolved to adapting to their varied environment.
In any ecosystem, the animals which are near the top are those who are :
1. Physically unchallenged (hippos, for example, have no natural predators)
2. Highly adaptable
I reckon tarantula who can vary their preferred habitat can increase their survival rate dramatically because :
1. By increasing the hunting area (not just ground level) they can increase their food source supply
2. By varying nesting locations both arboreally and terrestrially, a larger number of specimens can survive without competition in a smaller area
3. Depending on area, there may be a temperature/humidity advantage to being up in trees
One thing to remember, i think, is that most animals and insects are opportunistic - if there's an environmental advantage to be had, they'll find and use it and over time that's one way evolution is guided.
A case in point are the brachypelma tarantula from the South American regions.
I recently watched a lecture by Andrew Smith (very good, and worth the 2 GBP price tag for a 24 minute lecture) where he went in search of B. smithi, B. bohmei, B. emilia and others.
The point of note here was that B. emiliae were often found with their burrows created under large rocks/boulders.
The salient point here is that that in those environments, especially higher and dryer altitudes, the external tempreture would reach up to 42 degrees Celsius around 1pm !
By building their burrows under the rocks, they achieved two things :
1. Heat insulation
2. Humidity control
The temperature inside the burrows were around 28 degrees Celsius while it was 42 outside !
So the rock not only protected the burrow from direct sunlight, but by getting heated up itself, after the sun set, the rock would cool slowly, thus keeping the burrow warmer even at evening time.
Oh, and humidity was around 32-39%
They compared those with the much less efficient obligatory burrows created as a simple burrow with top-facing exit, and in between were those that built their burrows into cracks and crevices in rocks.
Physical Characteristics
More "hints" to their natural preference can be gleaned from their physical attributes.
Some common characteristics of arboreals are :
1. a lighter build with thinner bodies
2. longer legs with increased tarsal scopulation
3. light build gives them increased agility and protects them from falls
Being a newb, and only having two juvenile T's to compare with, these three differences are very apparent between my B. albopilosum and the C. fimbriatus.
Specifically, on the fimbriatus, the number I & IV legs are very long compared to the other two sets and to all of the curly's legs.
Also the body shapes are different with the fimbriatus being clearly thinner and longer, with a much longer abdomen, comparatively.
So in wrapping up, as we've seen from research and different personal experiences, some species are well evolved to adapt to, and take advantage of, varied environments.
Phew, I hope at least most of that is valid - experts and old-timers, please let us know.
Class dismissed. :thumbsup:
