No. Never mix species. That is never a good idea for a private hobbyist. Some people think that they can do this since they have seen it at zoos etc. Well – who says that the zoo knows what’s best…?
There are many reasons for not mixing and the reasons varies depending of what species we are talking about. One is that the animals come from different environments (countries, climates, temperatures etc). Another reason is different body mass – the bigger one can kill the smaller. A third reason is that the reptiles might have different gut flora. One might be resistant to a disease – and the other one is not. They can both get sick from this. A fourth reason is that they might be active during different hours during the day/night.
Some inputs from other people about this subject
One of the main reasons for not mixing species outside of the obvious (one thinking the other is a snack) is bacteria and parasites. What is naturally found in one species gut for digestion and excreted out, can pass to the other species and be deadly.
Example: Coccidia is thought to be a natural parasite (in minimal amounts) in a bearded dragon and that the dragons own gut fauna controls its and keeps a balance. Except when a dragon gets stressed or some other illness allows that to bloom and get out of control.
Yet another species may walk in the feces or consume something that walked in it and have no other bacteria in them to keep it minimal and become a host to an overgrowth of it. Then in turn infecting the bearded dragon with an overload of oocysts the other species excrete out.
Another example and I am taking this from an email to me from a well known researcher of diseases of reptiles:
<quote> Did you know that if you culture the skin of a healthy normal lizard, you have over 60% of chances to grow an Aspergillus or a Penicillin?</quote> This exist on the skin of a lizard and can simply be a there as a contaminant and does not bother them, yet could be devastating if ingested by another species.
Other reason can include the environmental and nutritional needs of one species over the other, what one thrives in, could be harmful to the other. Ex: the humidity a water dragon or iguana likes, would be dangerous to a bearded dragon as exposing them to the possibility of fungal yeast or mold infections that is not a problem for the more moist loving reptiles.
The Reptile Rooms
I would say that the simple reason is because they are captive in an artificial environment.
Someone will say, "Well, there are lizards & geckos & turtles & squirrels & raccoons etc all living together in the wild - why can't I put them all in my tank?"
There is no ability for the tortoise to dig a burro to get away from a hawk in a tank.
There is no means for a turtle to swim down stream & into the next creek to get away from a raccoon in a tank.
There is no way for a little gecko to climb a tall branch and blend in with leaves to get away from a hungry lizard if none is provided in a tank.
We just cannot easily replicate all of Mother Nature's way of providing self-protection / camouflage for several types of species in one enclosure. Zoos can do with huge enclosures, some acres big, but in a home of a reptile hobbyist, it's just not practical.
The biggest, most aggressive species in the tank will be the lone survivor.
I agree with Cheri's & Sharlas statements so far for sure. There are certain instances where it can be ok, don’t down it, before you know everything. Now I know, everyone who is just getting started with reptiles wants to do a mix species exhibit, but they shouldn’t, because they need the experience in caring for one reptile at a time, and more but only in separate cages. Your beginner reptile hobbyist will mainly try and do things as cheap as possible so a big enough cage is usually out of the question. But keep in mind an experienced hobbyist, with a very large cage, could make an interesting Australian exhibit. It would have to be at least 6 feet tall, 10 ft wide and 3-4 feet back to accomplish this, but I have seen it done successfully. First you have 4-5 Frilled Lizards which use the full height of the cage. Then you can add in a trio of Blue Tongue skinks that utilize the bottom. And fill in with a troupe of bearded dragons 4-5 strong. I have always thought about doing this, and if you have the time, experience and know how to keep a watchful eye on all, it’s a very doable set up.
I do agree that for a beginner though, mixing species is wrong, and here is another reason why. Even with something that lives in the same area and have the same requirements - how will some one, not experienced enough, make sure that in a small cage, the species cohabitate? As in eating right, eating the right amounts, not feeling stressed by the other animal, or attacking the other animal. A more experience keeper knows these signs and can separate if needed. Just my thoughts.
Well, one reason is that many reptiles come from completely different habitats, in entirely different continents. For example, two species you often see mixed together (especially in pet stores) is leopard geckos and African fat-tail geckos, and they shouldn't be. Leos are from the middle east, not Africa.
While you may be adequately providing correct housing conditions for one, the other is definitely not in optimal living arrangements.
The Reptile Rooms
Cheri mentioned the humidity needs of a different species. On the other end of the spectrum… I've often seen the question "Can a Uromastyx be housed with a beardie"?
Assuming they are both desert animals, people think there's no problem.
Desert climates can vary greatly. Just one instance, a Uro requires a 120-130 degree basking site. That would dehydrate and cook a dragon in no time.