vivarium theory

[fluxlizard]

Hello All!

I'm new here. I live in Virginia in the foothills of the Blue Ridge Mountains.

I've bred a variety of lizards for many years, but I've never used permanent outdoor vivariums like you all use. For the past dozen or so years, I've been bringing all of my lizards out into the yard for the summer and back indoors for the winter.

A year ago, I drove down to Agama International in Alabama to purchase some of Bert's old breeding stock, and got a look at the outdoor terraria he built during his life there.

Ever since I made that trip, I have been running what I saw through my mind trying to understand what he was doing, and wishing I could afford to buy his place!

Slowly over the past several months desire to make some outdoor terrariums that might be used year round for some of my lizards has been growing stronger and stronger. I have made up my mind to start by trying to make a few terraria this summer.

I have read all that I could find that Bert wrote, and I have carefully studied agama international's youtube videos www.youtube.com/user/agamainternational#p/u, and I have studied some work the benson institute has done with growing vegetables year round in pit gardens at high altitudes in south america bensoninstitute.org/visits/register_visit.asp?pdf=/Publication/Manuals/PanqarHuyu.pdf bensoninstitute.org/visits/register_visit.asp?pdf=/Publication/Manuals/Walipini.pdfand the last several days I have read probably about every post on these forums trying to learn more, but I still find I have some really basic questions.

Maybe someone would be kind enough to offer advice to me?


My main question is about hibernacula-

What is the target temperature I should be trying for?

Am I trying to locate it deep enough underground that I just avoid freezing, or am I trying to go deep enough to keep things 10-15 degrees C?

Is it possible to make the chamber too deep so that the lizards crawl in and go to sleep but are never warmed in the spring so they never emerge? Or do they have internal clocks that tell them to check the weather up above every once in a while?

Do I need to go below the frost line?

When I was down looking at Bert's work, I noticed that many of the same species he was breeding in his concrete pit style terraria he was now breeding in above ground galvinized steel sided terraria as well. And he had a wide variety of terraria, indicating to me that he was constantly experimenting with ideas throughout his lifetime, or maybe adapting his theories to the terrarain (some were located on flat ground, others on hillside) or I am sure things also depended on species. But what I am wondering is if the pit terraria were really doing anything essential that his above ground terria with only the hibernacula located below the earth were not also doing.

I guess that's thing two- I'm trying to decide whether I should go with pit style terraria or just really good hibernacula in above ground terraria.

I currently keep a number of species that I am wondering about keeping in these types of terraria- Bearded dragons, veiled chameleons (I know Bert worked with both of these species a little, but I don't think he had a lot of success with either for some reason), sudan plated lizards, egyptian green toads, australian water dragons (from Bert's stock), Chinese crocodile lizards (also berts), Argentine black and white tegus (also berts). I was thinking I'd try 2 or 3 of these this year and see how they work out in the new terraria I build. I'm also sort of wondering about sandfish and forest armadillo lizards. Sandfish I haven't been able to find much info on. I have had half dozen for a few years now without breeding behavior that I have noticed indoors year round. In December I brought a bunch of lizards to do a little educational presentation for the local boy scout troop, and somehow a couple of sandfish that I brought in a small container were forgotten in the car on our return home that night (I thought wife had unpacked that particular box, she thought I had, and she had been traveling with them at her feet so they wouldn't tip over so they weren't with the other lizards in the back of the vehicle. 2 days later I returned to the car, opened the door and saw the little plastic box full of sand sitting on the passenger side floor. It had been well below freezing at night and day temps were only slightly above freezing, though maybe they rose a little higher in the car in the driveway. I thought for sure I had 2 dead sandfish. Took them out to my lizard building, reached in to remove the bodies and one moved ever so slightly and slowly. I put them in the terrarium and within an hour they had buried themselves, dug them up the next day and you would never have known anything had happened- they were fast and have done fine ever since. So I am guessing they may be good candidates for outdoor terrarium if I keep the wet off of them.

Any suggestions on which would be easiest?

Our weather here is pretty mild- I am able to keep lizards outdoors in cages from late spring when nights remain above 10c from Mid-May until the last week of september or first week of October when nights sometimes start dropping below 10c again. Most of the summer we have rain once or twice a week and day temps 29-31c with a handful of days each summer over 32c. Winter months most days are between 4 and 12c, most nights between 4 and -6. A few weeks are highs only -1 to 4c and a only a few weeks with nights -5 to -12 and a handful of nights or fewer slightly cooler than that. Most of the winter is cold and often damp with rain most weeks. But we do get snow especially in January and February. Usually 10 to 15cm and usually it melts within a couple of days after the storm. This past winter we had an incredibly exceptionally long cold spell and had lots of snow- a couple of storms with about 43cm and snow staying on the ground from Christmas until late February. That has not happened before in my memory.

So, that is my environment- anyone here on the forum have similar where they live?

I am fortunate to live where there are many native reptiles and amphibians- some species I've seen people here on the board keep- corn snakes, snapping turtles- several different species of turtle (eastern box turtles, eastern painted turtles, and more) and many snakes (black rats, eastern kings, eastern hognose, timber rattler, copperheads, and more) and many frogs (spring peepers are out calling for the past few weeks everywhere here) and I have read that we have the most diversity of salamanders in a small area in the world- we have many species in the mountains. Highlights include spotted salamander, red salamander, spotted newt (which becomes the beautiful orange eft) and the mighty hellbender and many many more. Also lizards but sadly not so many- eastern fence swifts, 5 lined skinks, broadhead skinks). So if anyone is ever wondering what native habitat is like for a cornsnake or snapping turtle- I can walk a few hundred yards and be in cornsnake habitat and I regularly get out of my car to move box turtles and snapping turtles off the road in the spring and fall.

Anyway, that is my intro, my plans, my questions and I just want to say I am looking forward to learning from all of you here.

Sorry this intro has been so long.

[Killian]

Welcome to the board! that certainly is an interesting introduction. You have raised some very valid points and some interesting questions. hopefully somebody on here will be able to help you out. I live in Ireland and it rarely if ever gets above 18C in the summer so the species you mentioned must be kept indoors. I concentrate on cold loving species therefore outdoors. There are some keepers on here from the south of Europe and one or two Americans. Do keep us updated on your plans though I will be interested to read more

[fluxlizard]

Thank you Killian.

only 18 c? wow- maybe that's why I see some of you guys using glass or plexiglass for your walls?

[viridis]

Welcome Fluxlizard you raise some interesting points.I was never lucky enough to meet Bert or see his enclosures first hand but read his articles avidly.He was really ahead of his times in breeding Lacertids and his theories about calcium and vitamin D3.
I live in the south of England and we had an exceptionally cold and prolonged winter with temperatures getting down to minus 5 or 6 celcius [sorry dont know the fahrenheit].I thought that I would losemost of my animals with the cold and damp but most of the adults have come through.However they are Lacertids from Northern and Central Europe so in their natural habitat it gets very cold and conversely hot in the summer.Most temperate lizards will hibernate naturally and mine were able to dig down in damp sand to about 450mm or 18".The sand had plenty of rubble and stones in it to break it up and allow the lizards to find their own depth.On top of this I put another thick layer of leaves about 300mm or 12" deep and half covered the tops of the vivaria with glass.This seemed to work for me.
I dont think you necessarily have to build tunnels or special hibernacula the lizards should be able to sort this out for themselves if you have a frost free patch of sand or light earth.It isinteresting to note tat the losses I suffered were lizards that had been previously overwintered indoors and therefore probably didn`t know how to hibernate properly.
I would think that you could probably keep Sandfish outdoors.Remember that they come from desert areas of North Africa so nightime temperatures are cold.You would have to ensure that the substrate warms up and even gets hot during the day which would entail a covering of glass and I am guessing that the hibernation period would be very short.Remember that you are unlikely to see them for very long as they do burrow a great deal,Now to contradict myself you are probably better keeping them inside in vivaria for this reason.

[fluxlizard]

Thank you for your reply viridis

I guess one of the keys I am wondering about is if the soil around the lizard has to warm in the spring or if the lizards will just sort of know when it is time to emerge.

Have you ever measured temperatures down at the depth your lizards hibernate at?

I'm trying to get frostline information for my area still, but I am afraid my lizards might have to get down 61 cm to get to a stable temperature... Maybe if I put a leaf pile over their burrows they would not have to go so deep? And maybe once temps warmed up above freezing in the spring, I could remove the leaves? Does this sound correct?

I think I may go with a couple of berts species this first year- probably the water dragons and tegus for sure. He said that both of those species were more or less dormant for several months of the year. I have also watched my temperatures and compared them with his every day and night for the past several months. Mine were not too different- a little colder in fall and spring for a little longer, and longer cold spells in the winter, but overall, not as much difference as I expected...

I may try a few bearded dragons- I have lots of bearded dragons and I have some individuals that have been kept in a cold room at 10-15 c since January 1st that are still looking good. So I think maybe I will try a few outdoors this winter as well.

Have you guys already seen the videos Bert's son Timo did on youtube this past winter? I linked to them in my first post. He was taking requests so I asked him to show me how the water dragon cages were built and he showed the enclosures for the tegus and the shinisaurus as well. I was enjoying the afternoon I spent at agama international so much and there was so much to see it was hard to take it all in, and I was focused on the lizards more than the enclosures, so it was really nice of him to put the videos up online for everyone to see. He shows how some of these were hibernated there in alabama and it is a pretty good introduction.

One thing I thought was funny- Hester told me that she and Bert would check on the water dragons sometimes in the middle of winter- they would dig in and reach into their hole, and a few minutes later the lizards would fill the hole in, even when it was quite cold out...

[viridis]

Hi Fluxlizard
I have not measured the hibernating temperatures but I would say that the lizards need to be able to bury down to frost free soil
I do have doubts as to whether Bearded Dragons will survive through a winter.As far as I am aware they are a desert species that require high temperatures.Bert had good success with Australian Water Dragons and Argentine Tegus but these are more temperate species.He also bred Lacerta strigata and timon Lepidus,I would have thought that these were more suited to your climate.if you can get any Lacertids they are generally very active and often brightly coloured.Species like L.bilineata,viridis or agilis.Even some of the smaller " Wall Lizards" genus Podarcis are good but they are escape artists.I believe there are feral colonies in various States of P.sicula.

p.s. your posts leave me with a warm feeling inside as they remind me of Lauel and Hardy !!!

[fluxlizard]

I think inland bearded dragons are the same lattitude as aussie water dragons. I need to get some weather data somewhere online I guess and take a look since water dragons are near the coast which might make a difference. I was sort of hoping the pit idea would make things less extreme so I could pull it off with them. I was thinking maybe even with a 55 gallon barrel of water in there for a heat sink or something.

I've been breeding bearded dragons for over 15 years and have done a variety of things to cycle them for breeding in that time. I have kept them for up to 4 months in previous years at 10-15c no problem. This year will be my longest- I'm trying to go from Jan1 to mid-may at which time I will be able to bring them outside for breeding (recent years I have done most of my breeding from Feb through May indoors and then taken them outside for summer weather). These extreme cooling temps and duration are not necessary of course- The past 7 years prior to this winter I have only done a very mild cooling in the winters- turning off my lights in November so they remain a rather cool room temp - swinging about 13-26 c. And it has worked just as well as the more extreme cooling, but I was interested in learning if I can extend dormancy length in anticipation of trying a few outside next year, and also because it saves on electricity if they are sleeping away the winter months. So, if the temp of the earth is 10-15 c 4' deep pretty most places on earth (see benson institute links in my first post) then in theory I would guess I would be safe if I can get them to use a hibernaculum that remains that temp in a pit- and maybe the concrete or block walls would act as a heat sink or maybe I would put a 200 liter drum of water in there to act as a heat sink so the pit warmed up in the days and nights remained above freezing and a little more mild.

Or am I dreaming?



I've never tried this kind of thing before.

Do you guys only keep lizards in your outdoor vivaria that come from quite similar environments to yours? I was hoping to try with one of the species I already own, but if that is the case, maybe I'll have to get something else...

[viridis]

I am not too well up on Australian temperatures but from what i understand the Water Dragons are found on the coast in south east Australia where it is cooler and more temporate but the Bearded Dragons are from the hotter,drier inner regions.would it not be possible to put them outside during the Spring ,Summer and Fall and bring them in during the winter?
As far as I am aware over in the U.K. people do generally keep lizards outside from central and southern Europe.Even so there are vast climate extremes within this area.
At a show in Germany I was talking to a man who claimed to keep Uromastyx outdoors{under glass] all year in Northern Germany .I was with an Uromastyx expert who seemed quite surprised by this.The German assured him that it was possible because the weather in Germany is bright and cold in the winter thereby allowing the vivaria to heat up.In Britain we usually get warm dull winters which would have a detrimental effect on the lizards.I only offer this as a theory and it might apply to your Bearded Dragons.

[fluxlizard]

Thank you for your comments Viridis.

To date that is pretty much how I have been doing my bearded dragons. I have been brumating them 2-3 months at mildly cool temps and breeding them mostly indoors in late winter through late spring and then bringing outdoors when night temps remain warm enough for the summer for my screen cages that sit on tables (above 10c). This gives me from about mid-may until the first week in october of outdoor housing before I haul all the cages and lizards back indoors for the winter.

This year, as I say, I am trying a longer colder brumation. I am considering the idea that maybe if I have a deep pit type outdoor terrarium I can access the flywheel effect that the benson institute talked about in those papers I linked to and keep my ground temp at least above 10. If I cover with plastic and add a big heat sink like a black 55 gallon drum filled with water, maybe I can cut 2 or 3 months off of my winter in the pit, and that would leave 4 or 5 months of dormancy for the dragons. Plus we have many winter days here that I think the temps in the pits would be warm enough that the dragons would wake up somewhat and have a chance to bask and drink if they wanted.

Maybe.

Or the other thought I am considering is trying something along the lines of what you are suggesting and do outdoor terraria that are on the ground as well as indoor terraria. Possibly I could cover the outdoor with plastic and lengthen my warm months here so I could get a few weeks extra in both the spring and fall because of the ground heat over what I am getting now with the cages on tables. Maybe I could lengthen "summer" enough that I would only have to bring the lizards indoors into a safe "cold room" like I am using at the moment for dormancy.

Since my last post I have done a little more homework on this project- I e-mailed timo for clarification about their steel vs concrete pit vivaria, and I checked a really great australian weather website to learn a little more about what winter is like for vitticeps in the wild.

From Timo I learned that the above ground cages were used only during the summer for waterdragons and that the pit terraria were used for hibernating the waterdragons during winter. The black and white tegus were overwinted in both style terraria, but were given plenty of insulation (leaves, carpet, plastic) in the steel terraria.

Australia has a wonderful website for checking weather history day by day, month by month with highs lows actual temps, mean temps etc here:

www.bom.gov.au/climate/averages/index.shtml

I checked alice springs, recommended for inland bearded dragons on another board, and using a range map for inland bearded dragons I checked several other locations for temps.

Looks like they have a shorter winter (4 months maybe?) and night temps usually not freezing (but occasionally a few each winter in some locations). In some locations it does get quite cold nights in winter though- close to freezing fairly often.

Bert also worked with uromastyx there in alabama. The ones he was breeding he went and collected himself from a location that had a cold winter climate so he could hibernate them in his terraria. I have bred mali uromastyx in past years, but cooled them very mildly for 2-3 months indoors (10-15 nights 16-23c day temps).

I am not sure what my winter sunshine is here - we have sunny days but maybe too many are cloudy in a row...

Thanks again for giving me more to think about with all of this.

I might make a few terraria and try things out and then get lizards to match the conditions. You mentioned lacertids- I've always been interested in jewelled lacertas, maybe those would be a good one... Actually all of the lacertas here on the board are just beautiful in their terraria, but I don't think they are available too often here in the US...

[barb1]

Hi, welcome to the site.

You have some interesting thoughts. Although I breed Lacerta Lepida and keep them outside, I am not an expert on other species. Mark may be able to give you some more expert advice and he has also been over to Berts place. I've alerted him to your questions.

You sound as if you are one the right tracks with the hibernation, it should be below the frost line. Reps seem to have an inbuild system for telling the outside temps. and as the soil warms up, I am sure they will come to the surface.

[mark68]

Hi Barb. I have read through this briefly. The problem is there is more I want to say than I have time for right now ! But I will get involved in a few days. Yes I spent a week at Agama int. while Bert was still alive. One thing I will say is that I am pretty sure the AWD cages were not designed with AWD in mind. I believe they were originally used for Phelsuma and Basiliscus sp. The climate here is very similiar to Alabama and I do not use sunken cages for AWD.

[fluxlizard]

It would be wonderful to get any thoughts that you might have then Mark. I'm pretty excited about trying something this year, I just am not sure what it will be yet. I'd be especially interested to hear of your experiences with your australian water dragons.

[fluxlizard]

Well for whatever its worth it looks like I'm going to go with above ground galvanized metal enclosures along the same lines as the ones used by agama international for their tegu pens and water dragon enclosures.

I decided against concrete for 2 reasons-

concrete too expensive right now (has gone up dramatically in my area the past couple of years and is very cost prohibitive)

also I don't think I will live on my present property forever. with the metal I can dig them out and dismantle and move them if I want. Concrete terraria in ground are forever.

I was happy to find that the metal is much cheaper than I had anticipated if purchased as seconds and leftover bits from roofing and siding jobs. In fact it is almost as cheap as low end plywood.

I plan to make banks of these terraria, cover with plastic in spring and fall and put bales of straw around the outside of the banks to try and insulate them and extend my outdoor season for the lizards by a month or two, and then cool them indoors in my cold room.

I've got an idea for bringing the heat up out of the earth passively as well.

Any tips before I begin construction in the next week or so would be appreciated greatly.

Wish this board had more activity. I feel sort of like I'm reinventing the wheel here instead of building on others experience...

[viridis]

I have been advised to buid my outddor vivaria from galvanised metal.I can certainly see the advantages of it as the lizards are unable to climb smooth surfaces,but I am put off by the finished look.
This site isn`t very active I guess that there are not many people keeping herps outside.Most of the people here are from the British Isles so our climate limits the number of species that can be kept outdoors.I guess if we could keep Royal Pythons or Leopard Geckos outside it would be different. ;D