Reptile Forum, Reptile Classifieds - CaptiveBred

[Sean]

I do not know if anyone else as observed this, upto now I have seen it in 2 species spenceri and glauerti. I never observed it in cumingi or panoptes or any other varanids that I have experienced.

With spenceri the tail spasm or jerks in a snake like movement as if they are aroused or excited by something, like a waving motion rather like a side winder. My animals are all housed separate but they performed the same behavoiur when housed together or when sometimes I was present in the enclosures.


With glauerti I have seen them do something similar and sometimes even vibrate their tails very rapidly.

As anyone else witnessed the same behaviour apart from myself and warhammer.

I am not talking about a typical defensive posture with arched back, tail curled ready to lash. The animals are in a relaxed posture, it reminds me of rather like a dog wagging its tail.

I never read anything that reports this kind of behaviour, but its very interesting.

[Sam Sweet]

Sean,
Wild V. tristis and V. glauerti will do this rather conspicuously at times if another individual is nearby -- I have only seen it in males. I have also seen tristis use an exaggerated version of tail-tip undulation when hunting for skinks in deep pockets of leaf litter. The monitors push under the leaves and go forward a couple of bodylengths, then raise themselves high on their forelegs and "rattle" the last quarter of their tails under the leaves. If a skink hidden under the leaves moves in response to this, the monitor pounces.

[Sean]

Thanks for sharing that information Sam, I find it very interesting to observe and exactly as you said. It seemed to happen when they were housed together occasionally and one of the individuals was fairly close to the other or as if they associated me with food when entering.

Interesting point that you say that you have only witnessed it in males.
The animal pictured above was sold to me on the basis of being a male and it also performs this kind of behavior, I know it is difficult to see but do you think that particular animal looks male because I find these very difficult to sex when comparing them to say something like panoptes etc.... I understand you would probably need shots from different angles and areas of the animal but what would your guess be from that photo?

[ilovemonitor-lizards]

i´ve seen it by all my gillenis, even the small ones and caudolineatus. and also all males of tristis, acanthurus and storri. also several times when one of the acanthurus females get´s nervous after or before laying eggs. regards martin
_________________
keeping: Varanus:
acanthurus
gilleni
tristis orientalis
tristis orientalis red head
panoptes panoptes
caudolineatus
varius
salvator cumingi
Brachylophus fasciatus
Petrosaurus repens

[Patrik]

i have seen it in tristis,glauerti and gilleni, and by both males and females.
and most of the times that i have been witness to this behavior they have been sitting in a vertical position on the cork bark wall.

[Sean]

Ok we have all witnessed it then, as it ever been documented anywhere?

[Scott W]

[Nelson]

You can add Ackies that live with Bearded dragons to that list too

Having only owned one monitor I assumed it was standard and well documented.

[glebopalma]

I've seen it by V. t. tristis, V. glauerti, V. a. acanthurus and V. gilleni. They all live separated.

[Sam Sweet]

Sorry Sean,
I haven't any experience sexing captive V. spenceri, and the only wild animals I've handled where I was reasonably sure of sex were a good bit larger. V. spenceri are such pinheads as juveniles and subadults that I'd be reluctant to go by head shape. Also, while I've only seen male goannas do the tail undulation act myself, I have not kept these species as captives; there is no strong reason to think that females will not do the same, in part because we do not know its function as a signal.