Prehensility in the tails of Varanids (Monitor Lizards)

[infernalis]

As noted and photographed in the behaviors of Littlefoot & Cera, They have both displayed use of their tails in both balance and grasping to assist in climbing.

The use of the tail for grasping and balance is nothing new, and quite common in all arboreal species, and some terrestrial species, But I have not found anything implicating that this is a common practice in the stoutly built African species such as V. exanthematicus.

In layman's terms, has anyone else who keeps captive Savannah monitors witnessed the use of their tails for climbing down from elevated locations?

As we all know, these lizards posses very strong tails, yet very little is mentioned of the use of this tail in daily activity aside from a good slap when angered.

Evidence is building that Savannah Monitors are actually quite good at climbing, witnessed both in captivity and in the wild, the use of the tail to assist in this activity is of great interest to me.

So, share your observations, have you seen your lizards use their tails as a means of grasping or balancing while moving about?

[SpOoKy]

I actually notice it quite often Wayne. Usually while trying to get down from the basking stacks, mine will start to crawl off nose first, then front legs, then back legs and he/she will use their tail to balance the hanging body while he turns around to slide quickly into the borrow underneath.
It usually only happens when I run in the room quick while basking. Another time he will climb down at his own pack, usually do a quick scout of the enclosure then go into the burrow. It is almost like when he is trying a quick get away he uses every limb possible to get safe and secure again. Of course he/she will use the tail for tripoding as well.
I will have to try and get one of my camera's working so I can get a video of it.

[dinosaurdammit]

When I had my nile he would actually use his tail to dangle down and catch crickets n such, pajaaamas does the same. Ive seen baby savs do it more than adult savs though and I am not sure if niles continue to have such ability when they are larger. Pajaaamas uses his tail to wedge into things to hold on rather than curl it though he does from time to time. It would be interesting to see how arboreal savs can be

[jarich]

Im not sure I would refer to it as prehensile in Bosc's. With arboreal species you see the definite tendency towards a curling of the tail that facilitates that actual grasping, like in prasinus or salvadorii. These species seem to have thinner tails also, so that the tail can curve to the side. The thick, stout, straight tail of exanthematicus doesnt seem so much a specific adaptation like that but rather more of a general adaptation, like a rudder of sorts.

Mine has a tendency to just sort of guide himself with it; as he slides off the branches he doesnt so much grab with it as he does guide the direction he falls. They dont seem particularly graceful on decent, but maybe thats just mine.

[infernalis]

I have seen Littlefoot in particular, wrap the end of his tail onto the edge of the enclosure front door to descend to the floor like a grappling hook.

I have never seen either of them do a full wraparound, since that would be virtually impossible to do given the rapid taper and stout construction of the tail.

In one of my tripod photos, He clearly latches onto a rock for balance.

Originally Posted by dinosaurdammit

Ive seen baby savs do it more than adult savs though

I often wonder about this, Most captive observations made to date have been overweight animals that no longer display any behaviors aside from waiting to eat.

[jarich]

I would guess that for all species the abilities of the tail would be lessened in captivity also. Muscle tone is less in captives pretty much across the board on reptiles, so I think it would be safe to assume its true in this case too.

[dinosaurdammit]

Originally Posted by infernalis

I have seen Littlefoot in particular, wrap the end of his tail onto the edge of the enclosure front door to descend to the floor like a grappling hook.

I have never seen either of them do a full wraparound, since that would be virtually impossible to do given the rapid taper and stout construction of the tail.

In one of my tripod photos, He clearly latches onto a rock for balance.



I often wonder about this, Most captive observations made to date have been overweight animals that no longer display any behaviors aside from waiting to eat.

i think its something to think about, i would guess with captive savs, that at least 80% are overweight or not meeting wild brethren. This might dampen the ability to do the natural things they would normally accomplish. I think for fat monitors it would be impossible. Unmuscled tails, with huge sagging guts. I feel this would be the same as a heavily obese and unfit person trying to do a pull up on the monkey bars. It just wont happen. It would be lucky that they could even hold on to the bars for any length of time, same with a monitors tail. A fit monitor can stand and support all their weight ON their tail alone without propping on anything, but ive never seen a fat monitor even tripod.

[infernalis]

in an attempt to scale a smooth wall, I photographed Littlefoot supporting his entire body by his tail.

[murrindindi]

Hi Wayne, most species that have a relatively long tail would probably be able to use it the way you describe your monitors doing, simply because the tail is so muscular and like the body, flexible.
In which case, you will hopefully find some more stout branches for them very, very soon (they love showing their abilities off)!

[murrindindi]

Originally Posted by infernalis

in an attempt to scale a smooth wall, I photographed Littlefoot supporting his entire body by his tail.

If you watch closely you might see how they actually press the appendage into the object they`re climbing, adding more support.

[murrindindi]

Originally Posted by dinosaurdammit

When I had my nile he would actually use his tail to dangle down and catch crickets n such, pajaaamas does the same. Ive seen baby savs do it more than adult savs though and I am not sure if niles continue to have such ability when they are larger. Pajaaamas uses his tail to wedge into things to hold on rather than curl it though he does from time to time. It would be interesting to see how arboreal savs can be

Hi, yes even in adulthood their tails are still used that way to great effect my (late) Ornate monitor weighed just over 20kl (50lbs), but would use the tail to help him climb up/down.

[alessia55]

Originally Posted by infernalis

in an attempt to scale a smooth wall, I photographed Littlefoot supporting his entire body by his tail.

You should share this photo with us. It would be so appropriate in this thread!

[infernalis]

Taken from the littlefoot & Cera thread. (Excuse me that I fogot his left rear foot was used to balance on the edge of the enclosure)

Originally Posted by infernalis

The most impressive part of this photo, he is attempting to climb a pane of tempered glass I have for building another enclosure, so he is supporting almost all of his weight with his tail! (The albino garter snake takes great interest in what is going on.)

[infernalis]

The problem with having so many pictures of my monitors, I am trying to find some specific photos, and they are all over the place, making it a real challenge to find certain ones.

[jarich]

GoPro! Do it in style...