If you plan correctly, you can create a habitat that will allow you to keep a variety of species of reptiles and amphibians communally. It is a great challenge, but it can also be great fun.
To maintain a community tank successfully, you will have to know the habits of the species involved, be sure that your specimens are in excellent health, avoid serious size discrepancies and be certain that the animals are non-predaceous (meaning they won't eat one another).
Animals that seem reasonably benign in the wild may not be so when captive and crowded. For example, a captive toad that may ordinarily feed upon invertebrates may readily eat small lizards, salamanders or smaller toads when forced into close proximity.
Some of the most beautiful species will prove predaceous in the terrarium. Collared lizards may eat smaller lizards or snakes of any type. Ranid frogs, such as bullfrogs, are remarkably efficient predators and will stuff surprisingly large cage mates into their large mouths. Tiger salamanders may eat small horned frogs; in turn, they can become prey for large horned frogs.
African clawed frogs will eat smaller aquatic cagemates, including prized fish, small salamanders and smaller frogs. Large skinks (broad-heads and Great Plains) will preferentially eat smaller skinks of their own or other species. Most snakes – even those that supposedly feed only on endothermic (warm-blooded) prey – will eventually eat an ectothermic cage mate if the opportunity presents itself.
The Problem with Males
Male reptiles and amphibians can be particularly problematic. Once they are settled in and have established their territory, only a single male of a given species can be maintained in each terrarium.
This means a full species – not subspecies. For example, although they may look different to us, the four subspecies of the Madagascar giant day gecko have mannerisms so similar that the male of one subspecies will be bullied by the male of another. Should you choose to keep more than one subspecies, each must be kept in a different enclosure.
There may be cases where even though they are different species, the mannerisms of two herps will be so similar that they will prove incompatible. Such a case was demonstrated when we attempted to maintain breeding colonies of Madagascar giant day geckos and Standing's day geckos together. These are two fully different species. Initially, the male giant day gecko pursued the male Standing's day gecko mercilessly. However, within the day the tables were turned, the male Standing's was dominant, and their squabbling was so incessant that it was necessary to remove the colony of giant day geckos to prevent injuries.
Females are usually less territorial (even though some species establish hierarchies) and one male and up to several females will usually be compatible.
Some Herps Just Don't Get Along
No matter how much care you take, some herps cannot be kept communally. Some examples of non-communal species are: most monitors, all milk and kingsnakes, African mole snakes, most pythons of the genera Leiopython, Liasis and Apodora, tegus, African giant bullfrogs, horned frogs, American bullfrogs, large snapping and alligator snapping turtles, large Mexican giant musk turtles, indigo snakes and cribos, and any other snake-, lizard- or frog-eating herp species. Even baby turtles of usually benign species can and will nip off the tail tips of their cage mates.
Should you wish to maintain a community herp tank, you can do so. But it is important that you research all of the potential problems and thoroughly understand the mannerisms of your herps. Intimidation, stress, and overt dominance can be manifested by body language alone; physical skirmishing isn't even necessary. Watch carefully that all specimens are comfortable enough to eat and drink, bask and move properly. When this is determined, relax and enjoy the beauty of your community creation.
Communities in Action
So what species can you house together? The larger your cage, the longer the list will be.
We traditionally provide wood-framed wire step-in cages (6 feet high by 2.5 feet wide by 4 feet long) for many of our herps during the warm months of the year. In one we keep a trio of Standing's day geckos, a trio of Jamaican anoles, a pair of Tokay geckos and three or four curly-tailed lizards.
In our large "iguana palace" (16 feet long by 10 feet wide by 8 feet high) we keep a trio of rhinoceros iguanas, a trio of great green iguanas and a trio of frilled lizards.
In a simply furnished 220-gallon terrarium we keep a hodgepodge of American and Asian rat snakes – about 15 specimens of eight subspecies and species.
A 50-gallon terrarium holds a pair of Mali spiny-tailed agamids, a pair of Taylor's beaver-tailed lizards and a few whiptails.
In a 150-gallon filtered aqua-terrarium we have 15 assorted baby turtles (painted, red-eared, red-bellied, toad-headed, etc.), two large ornate bichirs (a tropical fish) and several "sucker-mouthed" catfish.
Our 40- by 32-foot backyard pen houses several radiated tortoises and many box turtles (both American and Asian), some of which having lived in harmony for more than 40 years.
A 75-gallon savanna-style terrarium contains about a dozen garter snakes (eastern black-necked, flames, checkered, etc.) that dwell amiably together.
A 45-gallon hexagonal rainforest tank is home to a dozen assorted treefrogs. These run the gamut from Australian White's treefrogs to Borneo eared treefrogs, American barking treefrogs and Malaysian flying frogs.
On a desk is a 30-gallon high terrarium, decorated with small orchids, vining pothos, many corkbark hides and transverse limbs. Several species of day geckos – neons, gold-dusts, blue-tailed, and ornates – thrive and breed within.
When we are establishing these tanks, we put all the inhabitants in simultaneously (but this is not truly mandatory), and we spend long hours watching the interactions of the reptiles and amphibians, always ready to remove and replace any that seem to be overly aggressive or that may otherwise not fit in.
Always furnish your terrarium to benefit all species included in the community. For example, day geckos like limbs of fair diameter, anoles will clamber through slender twigs, and curly-tailed lizards are adapted to life amid boulders. When the community terrarium is set up properly with resting, hiding and feeding areas, the potential for any adverse interactions between these three species are minimized and the possibility of a relatively normal lifestyle for each species is maximized.
It is important that you watch your specimens carefully at feeding time. In the community rat snake setup we feed each snake individually from forceps. The more voracious specimens may be placed individually in a covered plastic trashcan to eat. Two rat snakes may start eating at the opposite ends of the same mouse, and unless physically separated the larger or more aggressive feeder may overpower the smaller snake or the less aggressive feeder. This can also occur when feeding garter snakes earthworms or minnows. Always use care.