What should Varanid husbandry practices be like?

[monitorlizard]

What about the use of nest boxes?
I seen(what I believe to be) people with cages that have a very shallow substrate but have a nest box. Would that suffice, or is that completely unacceptable? Crocdoc, I have seen you use nest boxes, how deep is your substrate?

[Pirarucu]

Originally Posted by monitorlizard

What about the use of nest boxes?
I seen(what I believe to be) people with cages that have a very shallow substrate but have a nest box. Would that suffice, or is that completely unacceptable? Crocdoc, I have seen you use nest boxes, how deep is your substrate?

Some species, such as varius and rosenbergi, nest exclusively in structures like termite mounds, and so should be provided with something that replicates this for nesting. Some species usually don't burrow and therefore do not need the deep substrate throughout their cage.

I am in favor of offering dirt through the whole cage and offering nest boxes. Let the varanids decide what they need or don't need.

[monitorlizard]

What about the size of the cage? Varanids have huge territories in the wild. Now for the most part we obviously cannot replicate that, but how big do you think the minimum size for a cage should be.
I understand the idea of the length of the cage being twice the lizard's length with a width and height that are the same length as the lizard, but to a lizard from the wild that is only allowing the lizard to take a couple steps forward and then turn around. This obviously isn't applied to lizards under two feet, because they are give four plus foot cages. Why not apply the same to larger lizards? Rather then twice the length of the lizard for the length of the cage how about three times and instead of the length of lizard for the height and width why not twice the length? Or is that just not practical?

I think I understand FR when he said that an arboreal cage cannot be achieved in captivity unless you use an entire tree. When I see people with arboreal varanid enclosures I normally see shallow substrate with a bunch of four to six foot logs placed vertically to mimic a tree in the wild. But in the wild that would be just the base of the tree. Arboreal Varanids use not only the base but also the canopy fifty plus feet off the ground. Rather then bother with a substrate and mimic the base, how about trying to mimic the canopy by having the main structure of the enclosure logs, with nest boxes in the trees that resemble hollows frequently found in trees or termite nests that a monitor would lay its eggs in. Since the monitor is arboreal it wouldn't want to burrow.

[crocdoc]

Originally Posted by Pirarucu

I am in favor of offering dirt through the whole cage and offering nest boxes. Let the varanids decide what they need or don't need.

Bingo. I agree wholeheartedly.

Originally Posted by monitorlizard

Crocdoc, I have seen you use nest boxes, how deep is your substrate?

I guess you didn't read that exchange on KS (I'm teasing, as I know just how long it was).

The long and short of it is this: As Pirarucu has said, some species are termite mound nesters in the wild and it is my opinion (based on my own experience as well as the experience of many other keepers) that these species nest particularly well in nest boxes. I think offering them a choice is important, but for those species a nest box should be one of the choices offered.

In answer to your question regarding substrate depth in my enclosure - I used to religiously keep it very deep, but the female has never nested in it (she's done test digs, but never followed through). Now the depth varies depending on how frequently I top it up. It's still important for retaining humidity, but not important for nesting with my animals.

Originally Posted by monitorlizard

I think I understand FR when he said that an arboreal cage cannot be achieved in captivity unless you use an entire tree.

In a sense he's right, but the reality is still that some species will do better in a vertical enclosure than others. I don't think many monitors (other than tree monitors) are likely canopy users, but a lot of species do use trees for escape/security, for foraging and for basking, and these can be achieved in a tall enclosure that's not necessarily tree height. I know from experience, for example, that young, nervous lace monitors do much better in an enclosure in which they can get above my head height.

Even my adult lace monitors like to rest on the very short trees in my enclosure in the same way wild monitors do - vertically.

Alex, my male at home.


Wild lace monitor.


Alex, at home.


Wild lace monitor I saw three days ago.

[smy_749]

How do the varius eggs survive inside the termite enclosure? Termites don't eat away at or attack the eggs? Just curious...But I'm assuming after the eggs are laid inside, and the termites close it off again, it makes for a nice moist incubator lol Also, is there any way to recreate a termite mound type structure in your enclosure with a specific type of dirt (minus the termites) ? That would be pretty cool haha

Also we all know you can't achieve a 100 ft + canopy in your house, or anywhere for that matter unless you created an 10 story building with a tree in the middle. But everyone understands that saying arboreal when it comes to enclosures, just means if you have to choose between a 8 x 4 and a 4 x 8 , you would obviously choose 8 x 4 for a species which tends to be terrestrial, and 4 x 8 for a species which tends to enjoy being off the ground because it is MORE aboreally oriented. Its just that when I said the A word (its forbidden in some forums), some people assumed I thought it would be a sufficient substitute/equivalent for a rain forest canopy environment which anyone with sound intellect would realize is not what I meant :S

Oh...and I never get sick of those varius pics. The last 2 look very different, the smaller bottom one seems to have a longer skinnier snout, maybe its just the angle. Is that hanging position on the tree strenuous on the muscles, or do they just let the claws do the work and sort of dangle there?

[Pirarucu]

Originally Posted by smy_749

How do the varius eggs survive inside the termite enclosure? Termites don't eat away at or attack the eggs? Just curious...But I'm assuming after the eggs are laid inside, and the termites close it off again, it makes for a nice moist incubator lol Also, is there any way to recreate a termite mound type structure in your enclosure with a specific type of dirt (minus the termites) ? That would be pretty cool haha

Also we all know you can't achieve a 100 ft + canopy in your house, or anywhere for that matter unless you created an 10 story building with a tree in the middle. But everyone understands that saying arboreal when it comes to enclosures, just means if you have to choose between a 8 x 4 and a 4 x 8 , you would obviously choose 8 x 4 for a species which tends to be terrestrial, and 4 x 8 for a species which tends to enjoy being off the ground because it is MORE aboreally oriented. Its just that when I said the A word (its forbidden in some forums), some people assumed I thought it would be a sufficient substitute/equivalent for a rain forest canopy environment which anyone with sound intellect would realize is not what I meant :S

Oh...and I never get sick of those varius pics. The last 2 look very different, the smaller bottom one seems to have a longer skinnier snout, maybe its just the angle. Is that hanging position on the tree strenuous on the muscles, or do they just let the claws do the work and sort of dangle there?

Correct me if I'm wrong, but I believe he uses coconut husk/fibers in the heated nest box after experimenting with different materials.
In the wild, termites would not bother the eggs as they are too big to shift and are not food. They treat them like rocks that appeared in their mound.

As for the ten story building.. Moody Gardens has done just that, with a lot more than just one tree, LOL. The pyramid is ten stories tall.
The Croc Monitor can climb thirty or forty feet up in his enclosure if he wants to, though he usually doesn't.

[smy_749]

Originally Posted by Pirarucu

Correct me if I'm wrong, but I believe he uses coconut husk/fibers in the heated nest box after experimenting with different materials.
In the wild, termites would not bother the eggs as they are too big to shift and are not food. They treat them like rocks that appeared in their mound.

As for the ten story building.. Moody Gardens has done just that, with a lot more than just one tree, LOL. The pyramid is ten stories tall.
The Croc Monitor can climb thirty or forty feet up in his enclosure if he wants to, though he usually doesn't.

Ah ok makes sense. Although if they carry half the strength ants do, (Idk much about termites), you'd be suprised what a few thousand can move around/kill.

Do you have any pics of the entire enclosure? Is it a private place or a zoo?

[DeadlyDesires]

Originally Posted by Grendel

I believe in the first option, and strongly reject the second.

most deff!

[crocdoc]

Originally Posted by smy_749

How do the varius eggs survive inside the termite enclosure? Termites don't eat away at or attack the eggs? Just curious...But I'm assuming after the eggs are laid inside, and the termites close it off again, it makes for a nice moist incubator

The termites seal off the enclosure but don't harm the eggs. The reason monitors use these mounds is because they are moist and warm - perfect incubators - and remain warm all winter. It's no coincidence that the two species of monitor in Australia with the southernmost distributions both nest in termite mounds and both have eggs that overwinter.

Originally Posted by smy_749

Also, is there any way to recreate a termite mound type structure in your enclosure with a specific type of dirt (minus the termites) ? That would be pretty cool haha

Yes, I've been using a nest box that mimics the conditions of a termite mound, for many years. It's worked at treat.

Originally Posted by smy_749

The last 2 look very different, the smaller bottom one seems to have a longer skinnier snout, maybe its just the angle.

Mostly angle and age.

Originally Posted by smy_749

Is that hanging position on the tree strenuous on the muscles, or do they just let the claws do the work and sort of dangle there?

The latter. They dangle. When they are high up in a tree and want to stay there for a while (for example, to avoid a predator), they let the body hang and all of the limbs go straight, so the claws and tendons do the work rather than the muscles.

If you look closely at that bottom photograph, though, you'll notice that the tree the monitor is on is smooth and barkless. Only a monitor with claws sharp as fish hooks can climb that, but they have no issue at all.

Here's an example of a wild monitor hanging for the duration, with arms and legs straight

[smy_749]

Thats probably the best example you can show someone to give an idea of how sharp the claws are, Smooth surfaces, effortlessly hanging out, are you sure that last pic is not a gecko? :-P hahaha

I posted this question on another thread but don't remember which one, I'm posting too much and getting all excited...I read on a research paper that murrindidi sent me that griseus have hatchlings which hatch before the cold season, and stay underground, first emerging in the spring. Is this common in monitors? I found it strange being that typically in nature, animals are born in optimal growing/feeding season.(obviously winter is not the optimal season, being that they never emerge, or is it just outdated info..20+ years is a long time)

"Hatching the young-of-the-year takes place in burrows at the end of August and in September. Although some findings of hatchlings at the end of August and in September were reported (Ataev, 1985;Tsellarius et al., 1991), they appear, as a rule, at the surface only the next spring (Bogdanov,1986).

[crocdoc]

If that is the case with griseus (I don't know their natural history well enough to verify that), that would make sense for a monitor that lives fairly far north, where the winters are cold.

1. Monitor eggs have long incubation periods.
2. Monitor eggs require fairly warm temperatures for incubation (30C).
3. Baby monitors are better at seeking shelter and coping with cold than monitor eggs would be.

Imagine a pair of monitors mating in spring or early summer. The female lays eggs a month later and the eggs must incubate for several months before hatching. By then it's late summer or early autumn. One biological 'choice' would be to have a longer incubation so that the hatchlings emerge in spring, but in the places griseus are found the ground wouldn't be warm enough for eggs mid-winter this and there probably aren't any termite mounds in which to nest. Hatchlings, though, can seek shelter for the winter and can cope with quite low temperatures, lower than the eggs would cope with.

Something similar happens to livebearing reptiles in cold climates, like garter snakes in Canada. By the time the babies are born it is late summer and they may not get many meals in before heading underground for winter. They sometimes go straight down shorty after birth, without any meals at all.