Monitor Care & Natural History; Zoo & Pet Experiences

[bronxzoofrank]

Hi All,
I’ve had the good fortune of caring for 15-20 monitor species during my zoo career. From the diminutive Storr’s to the massive Water, Lace, Crocodile and Komodo Monitors, all have instilled in me the feeling that they were, somehow, “more complicated” than other reptiles. Indeed, recent studies have confirmed that they are, among lizards, highly advanced. While some are too large for the average household, several moderately-sized and even dwarf varieties are being bred by hobbyists, and all make fascinating and responsive captives.
The following information can be applied to the care of Savannah, Black Tree, Nile, Merten’s and most other monitors.
Read article here ************

Thanks, Frank

[crocdoc]

May I make a recommendation? I had a quick skim through your monitor care article (will read in more detail when I get more time) and noticed that you're recommending a basking spot of 90-95F. That's way too cold for a monitor.

Their preferred core body temperature usually exceeds that, so with that basking temperature they'd never be able to reach optimum temperature. It's best to have the basking spot a fair why hotter than their preferred body temperature, so they can achieve it quickly. A basking temperature of at least 120-130F is recommended for most species, some much hotter than that.

[bronxzoofrank]

Originally Posted by crocdoc

May I make a recommendation? I had a quick skim through your monitor care article (will read in more detail when I get more time) and noticed that you're recommending a basking spot of 90-95F. That's way too cold for a monitor.

Their preferred core body temperature usually exceeds that, so with that basking temperature they'd never be able to reach optimum temperature. It's best to have the basking spot a fair why hotter than their preferred body temperature, so they can achieve it quickly. A basking temperature of at least 120-130F is recommended for most species, some much hotter than that.

Hi,

Thanks for your input; we've done very well with those temperatures for a wide variety of species at the Bronx Zoo; colleagues elsewhere have done so also. Individual species vary in their needs, as mentioned. Basking animals are able to reach appropriate temps, and time spent under light has not been a problem (although I imagine this can be a concern in some situations). Best, Frank

[crocdoc]

Originally Posted by bronxzoofrank

we've done very well with those temperatures for a wide variety of species at the Bronx Zoo;

I beg to differ (as a frequent visitor to the Bronx), but I'm going to be polite and bite my tongue/sit on my typing hands.

Best

[infernalis]

Originally Posted by crocdoc

I beg to differ (as a frequent visitor to the Bronx), but I'm going to be polite and bite my tongue/sit on my typing hands.

Best

Please don't be quiet David...

[Toothless]

I just read the article, and it does contain alot of very useful information.
However, I would like to see what everyone's opinions are on the recommendations of sand/ cypress bedding, the basking temp range, and the low humidity for savannah monitors. These points seem to go against everything I've read about their care. Do you mind stating how long each monitor has lived for (or how old they are now), and what their set-up consisted of? I'm just a touch curious .
Other than that, I thought the article was pretty good .

[bronxzoofrank]

Originally Posted by crocdoc

I beg to differ (as a frequent visitor to the Bronx), but I'm going to be polite and bite my tongue/sit on my typing hands.

Best

Hello,

Thanks for the note. Certainly higher temps can be used as well; in my 21 years working there, we did had problems with monitors and a variety of species kept in huge exhibits that could not be heated properly (i.e. JungleWorld, in mid '80's), or where shy/stressed individuals did not use basking sites for a sufficient length of time. Best, Frank

[infernalis]

I am going to state my observations.

My first Bosc monitor was kept under similar conditions as you publish in that blog and he was under metabolised, his organs failed, he was in far from ideal shape, he became one of those lethargic blobs that barely resemble a wild specimen. He lived five years.

I have since tried again, with a big difference. I operate my cage with the coldest spot being deep down under the soil at approximately 75 degrees, the dirt averages 80 degrees mid depth, the ambient air inside the cage ranges from 80+ up to just over 100 degrees.

With current basking temperatures approaching 150 degrees (F) I have raised 2 Bosc Monitors that have a body shape identical to wild specimens.

Housing any Varanid in a fish tank is not something I would encourage, we simply cannot create the proper tropical conditions that these animals need with a common aquarium.

[crocdoc]

I can recall seeing your previous pair of lace monitors before they died and they were suffering from assorted metabolic issues, such as gout, related to insufficient heat. They weren't that old.

The newer ones aren't that old, either (I saw them as juveniles right before they were shipped over there, when they were off display at the zoo here in Sydney), but are heading in the same direction for the same reason. I entered the enclosure with the keepers to check it out.

I do recall a large Varanus salvator you had in Jungle World (I have photographs of it somewhere). It would definitely have been difficult getting a basking spot onto those displays.

[infernalis]

Originally Posted by Toothless

I just read the article, and it does contain alot of very useful information.
However, I would like to see what everyone's opinions are on the recommendations of sand/ cypress bedding, the basking temp range, and the low humidity for savannah monitors. These points seem to go against everything I've read about their care. Do you mind stating how long each monitor has lived for (or how old they are now), and what their set-up consisted of? I'm just a touch curious .
Other than that, I thought the article was pretty good .

History has proven those conditions as less than ideal for long term health.

[AjaMichelle]

Thanks for not staying quiet David!

[_Varanidae_]

Greetings,

Highly relevant to this discussion, here are some direct quotes from a recent study that looked specifically at mortality in monitor lizards at the Bronx Zoo:

Out of 85 animals analyzed:

"Gout was responsible for nine deaths and was considered a significant secondary complication in an additional seven, bringing the total incidence of gout to 18.8%."

Given the history of poor supportive husbandry regarding the thermal demands of varanids discussed earlier, inadequate basking temperatures could play an important contributing role in the development of gout. Providing captives with appropriate thermal gradients and access to surface basking temperatures in excess of 45◦C may reduce occurrences of gout.

The quote "discussed earlier":

"Recent advancements in husbandry have shown that varanids require surface basking temperatures in excess of 45◦C, with some species regularly seeking out and basking at surface temperatures exceeding 60◦C in captivity [Husband and Bonnett, 2009; Lemm, 1999; Retes and Bennett, 2001]. Zoo exhibits, particularly those on public display, may not provide sufficient basking temperatures since lighting and heating fixtures are usually placed out of public view, often at considerable distances from the nearest basking area..."

[bodiddleyitis]

The biggest breakthroughs in monitor lizard husbandry in the last quarter century have been the recognition that access to high basking temperatures and increased humidity are necessary to allow the animals to metabolise freely. As far as I am aware this is true for all species. It's disappointing to read that savannah monitors "develop health problems in damp enclosures" when all the available evidence suggests that most die because they are kept much too dry.

[infernalis]

Originally Posted by bodiddleyitis

It's disappointing to read that savannah monitors "develop health problems in damp enclosures" when all the available evidence suggests that most die because they are kept much too dry.

With that in mind, My two Boscs freely chose to spend time down inside burrows that I have measured humidity reading nearing 100%

With a wide range of humidity and temperatures made available to them, these animals seek out very hot and very humid locations within the enclosure completely on their own.

[varanus_mad]

I have no idea how at this pointt in time thete are still zoos using and recommending husbandry that kills varanids.

If you doubt the above posts you should try there recommendations?

You will be impressed with the differences in behaviour.