There is a wide range of North American rat snakes available in the UK pet trade. These are commonly kept due to their manageable size, largely docile temperament and hardiness. The genus Pantherophis includes the corn snake, Pantherophis guttatus, grey rat snake, P. spiloides, baird’s rat snake, P. bairdii and the Everglades rat snake, P. obsoleta rossalleni. The corn snake is the most popular, arguably due to the huge variety of selectively bred colour and pattern morphs. It is likely that due to the similarity of these species and through some intentional or even accidental hybridisation, the captive bloodlines have become somewhat mixed. We think this may be the case in a snake we recently added to our collection – a juvenile rat snake from our local reptile rescue centre. Yet he most closely resembles the Everglades rat snake.
This species is found, incidentally, within the Florida Everglades. As such, it has become adapted to riparian habitats and therefore may require higher temperatures than some of the other North American species. They have keeled scales, an adaptation that helps snakes grip onto branches, suggesting that they are avid climbers. They are fast, slender and can be highly active when provided with plenty of mental stimulation.
When planning an enclosure for a new reptile it is imperative to look to the wild conditions from where they inhabit, as per Wild-Recreation®. The Everglades is made up of a series of rivers bordered by long grasses with intermittent cypress trees. As such we need to provide opportunity for climbing and grasses for ground cover within which the snake can hide.
The ultraviolet index available in Florida reaches an average of UVI 8 in the summer. To formulate an ideal UV index to provide within the terrarium, we typically lower this by 2, to account for cloud cover. We then think about the behaviour of the particular species. We know that they actively bask in partial sunlight by exposing part of their body to the sun. Or, they may bask long grass so as to remain hidden whilst utilising the energy within the Sun’s rays. Therefore we reduce the index by a further 2 units. This gives us a target of UVI 3 to 4 as the maximum basking index we should provide. Remember that in the wild the available energy will be lower in the cooler months and higher in summer. For accurate solar replication the animal should be given this index at the basking zone, descending down to UVI of 0. This is the basis of the Light and Shade Method. This ensures that the snake can use average wild-like ultraviolet A and B throughout the year.
We must provide a basking area warm enough for the animal to raise its temperature to the level required for its biological function. Then we use lower areas so that they have the element of choice. We wanted the basking zone to reach as high as 33oC.
A lamp array was chosen to create a flood of wavelengths ranging from heat, through visible light and into the ultraviolet range. For heat we use an Arcadia Reptile Deep Heat Projector® with a dimming thermostat. This lamp provides natural Infrared wavelengths, creating a gentle yet effective heat that powers into the muscle tissue of the animal. We then matched that with a 22 watt Jungle Dawn over the front half of the enclosure, next to the heat lamp. A 24 watt D3+UV Flood was added to the back so the three lamps’ outputs converge together over an energy-rich basking zone as per the Light and Shade Method. All three lamps were set over to the right-hand side to allow the left-hand side to descend into cool and shade. This is the basis of self-regulation.
Using a glass terrarium, we aimed to recreate a corner or snippet of the wild-like environment, whilst providing a secure, safe habitat with space for various behaviours including climbing, hiding, bathing and basking. Coincidentally we also find that doing this results in an aesthetically pleasing environment for us humans to enjoy!
It is an option of course to leave the glass sides of the terrarium clear. Yet we feel that reptiles will feel much safer if a naturalistic background is used to help them feel more secure. Blocking the glass with a natural material such as wood also helps to retain the heat. This not only reduces running costs but extends the length of the heating equipment as it does not need to work as hard to be able to maintain the set temperature.
For this background we used naturally dried birch bark sheets as these have a warm woodland tone and are cut to size so are easy to attach to the glass. When designing a vivarium we need to check that nothing we include could cause harm to the inhabitants. In this case we used an aquarium-safe clear sealant to affix the panels. It’s easy to use as it does not dry straight away so you have a bit of free reign to move things around as you are working to make sure you are happy! Once fully dried and left for any fumes to dissipate, this material is completely safe for animals. When applying it though, it smells quite pungent so we used it in a separate room to our reptile room, with good ventilation to avoid any harm or distress to the animals. We left the silicone to set fully before adding more layers of shredded bark to add texture to the back panel of the build. The whole thing was then left for a further two days to make sure it was completely cured.
Once the background was complete we could get on with designing the decor. We used dried cork branches throughout and positioned them before adding the drainage media in order that they would remain stable once the rest of the substrate was in place. We used three bags of EarthMix Arid. Then we could get our grasses in.
Carex grasses are commonly available in garden centres and are relatively hardy – a must for most vivarium builds! The plants were bought a week in advance of adding the snake and rinsed off the leaves gently with warm water to remove any potential pesticide residue.
It takes a bit of playing around to get the plants in the position that you want. We found it easier to do this then top up the substrate level afterwards. We could then add the essential hides, only using natural decor such as coconut halves and ceramic hides. These are free from resins found in non-natural hides that could potentially release VOCs. Finally we placed a large ceramic bowl of water in the cool end to allow for bathing.
To make a vivarium truly ‘bio’ we add in the custodians as a last step. These include our own mix of springtails and tropical woodlice that will break down the waste products in the vivarium and any dead leaves. We sometimes add mealworms to this mix but we thought that they may be too large for this small system and end up feasting on the plant roots.
One of the joys of designing a new terrarium is not only the initial steps, but observing how it develops over time. Plants need particular attention at first to prevent them drying out and dying back. As the terrarium has a mesh top, the ventilation is good so heavy watering will not raise the humidity too high. We wanted to see a layer of humidity maintained in the drainage layer rather than standing water so we target watered them every one to two days. The beauty of the EarthMix Arid substrate is that it will maintain a dry layer on the top whilst holding humidity that the plant roots will benefit from.
Since introducing the snake back into his enclosure he has been showing excellent colour and activity. He has not refused a feed and will move between the humid ceramic hide, rock stack and basking area as he pleases. After a feed he tends to sun himself under the lamp array. The viv in its current state has been running for about a month so we will post up an update on it in the weeks to come.