Is it Safe to Mix Reptile Species?

The short answer is “No.”

While a mixed-species ecosystem is often seen in zoos and other institutions, this is not something that should be attempted by a hobbyist unless they are extremely experienced, with the resources needed to maintain and keep a mix-species terrarium – and certainly something that should never be attempted by a beginner or casual reptile owner.

A vast amount of time, research and space, not to mention money, is required to create a successful multiple-species enclosure and most zoological institutions have access to the budget, specialist staff and a full-time exotic-specialty vet needed. Most hobbyists have none of these resources and may struggle to even keep several members of the same species together, never mind a mixed-species community.

Here are reasons why mixing species is a bad idea:

• Unlike fish where several species may have very similar requirements, most reptiles have very particular needs with regards to things like temperature, lighting and humidity. Even those that originate from the same area (e.g. arid environments) may have very different habits and occupy a very specific niche within that habitat. These micro-climates that exist naturally in the wild translate to drastically different care in captivity. In the unnatural captive environment, it is hard enough correctly replicating the natural environment for one species, for perfect health and well-being, never mind trying to achieve this for multiple species. It is almost impossible to keep different species together without compromising the care of one in order to accommodate others. This can lead to stress, illness and possibly even death.

• Space is a key issue: most recommendations for single species are the MINIMUM required for health and already do not provide the same freedom as the wild. If different species are to be kept together, it is vital that each as enough “space” to regulate their body temperature, hunt for food and have enough of their own territory to behave normally without the threat of aggressive cage mates causing problems. Even species that normally occur together in the wild rarely come near each other (unless one is trying to eat the other!) whereas the limited space in captivity means that they are much more likely to interact with each other in a negative way. Yes, zoos and similar to achieve multiple species communities but their enclosure sizes are not possible or practical for the average hobbyist in the home.

• Predation is a serious issue and many carnivorous reptiles will happily eat anything that moves. Even when keeping members of the same species together, it is a good idea to choose individuals of similar sizes as cannibalism can be quite common!

• It is almost impossible to provide the correct temperature gradients for the different species within one tank or enclosure. Similarly for humidity. Even species that come from the same habitat in the wild may occupy very different niches – some may be strictly arboreal, some may be semi-aquatic, others may need deep soil substrate to burrow – and it is impossible to provide adequately for these different needs in the space of most average hobbyist tanks.

• Diet is also an important consideration and most species have very defined requirements. Even those that eat the same food may need different sizes. Furthermore, the more dominant or stronger individuals in the tank will often bully the weaker ones, leading eventually to the death of the weaker species.

• Parasites and infectious diseases may be easily transmitted and what may be simply a nuisance to one species can be fatal to another.

While there are hobbyists who have successfully managed to maintain a mixed-species tank, this is the exception rather than the rule and not something that would be recommended by most experts. At best, the results are unpredictable and at worst, they can be devastating for all involved.

If you really want to create more interest, then consider a large tank where different species are separated by glass dividers. But make sure that each species still has the same amount of space and is provided with the same requirements as it would have if it was being kept singly. Remember also that even though they are physically separated, the reptiles may still feel stressed by the presence of others close by (particularly if they are potential predators).