Why Moisture Is Important!
Sometimes I feel like a bit of a broken record but hey, in the end it shouldn't matter how many times you have to say or write something when it comes to helping animals and the keepers that just want to do the best for them. There's still a ton of outdated and inaccurate information regarding the care of turtles and tortoises all over the internet and it can be very frustrating for someone such as myself to try and break through it with what can actually save an animal's life. Well, here's another go at it. Moisture and hydration is absolutely crucial to the survival of ANY turtle or tortoise. There is no argument here. Species from tropical, sub-tropical and temperate regions need it and so do those deriving from arid ones. Sure, certain species have adapted to an arid environment through evolution but they still require water in their lives to some extent. In some cases, they require more than we care to realize.
Turtles and tortoises, like this young adult radiated tortoise (Astrochelys radiata) to the left need to be able to drink but they also need to be able to absorb moisture through the skin and shell. This is particularly critical when they are very young. It's staggering how many hatchling chelonians die an untimely death from keeper error which is often because they suffered severe dehydration leading to organ failure. Let's face it, many of us grew up on books about these animals that suggested keeping them in dry conditions on heinous substrates like rabbit pellets, corn cob bedding or aspen shavings. While those books may be nostalgic to us (I admit, they certainly are for me), they caused terrible deformities in these creatures and of course, countless deaths.
By now we are all pretty familiar with "pyramiding" which is the unnatural raising of the carapace scutes. This creates a bumpy or pyramided look but in some instances, the specimen is horribly deformed. This poor gopher tortoise (Gopherus polyphemus) is a prime example of deformation from improper care. Taken illegally from its wild Florida home and then raised completely dry in a fish tank, this endangered tortoise perished way too young in life. You can see how awfully deformed the shell is from dehydration and how overgrown the beak is from being fed an inappropriate, soft diet. At nearly adult size, this gopher tortoise's shell was pliable instead of being rock solid bone. It was altogether a very, very sad situation. Things aren't always this extreme, though. More often than not a tortoise or turtle still lives an otherwise normal life because the pyramiding of the shell isn't severe or it was caught in time before other parts of the body (organs for example) were compromised.
Sometimes, all it really takes is studying the wild habitat a species comes from. In the case of that gopher tortoise, all one needed to do was look into the ecology of the animal. Sure, it's downright illegal to take any gopher tortoise out of the wild but the point is that the people responsible didn't just break the law, they allowed the animal to suffer and die early. They're gopher tortoises....they burrow...they live in FLORIDA....where it's humid...really, really humid. Speaking of humid places and burrowing, this is where things typically go wrong from the very start. Babies must be able to burrow into moist substrate of sufficient depth to be able to subject themselves to a humid microclimate. We often pay more attention to keeping the air humid inside an enclosure which does have its benefits as we can see with this wonderfully developing, young western hingeback tortoise (Kinixys nogueyi), but we fail to recognize the importance of the substrate, at least for some species.
Like box turtles, some tortoise species choose to spend most of their time hidden in leaf litter or just below the surface of the ground in moist earth. This doesn't just go for obvious forest-dwelling species but it also goes for European ones and some others too. Hermann's, Russian, marginated and Greek tortoises subject themselves to staying hidden in a humid microclimate a high portion of the time while they are young and more vulnerable. They will expose their shells partially to soak up the sun in order to reach an optimal body temperature and then quickly move on to grazing. Before the extreme heat of the day, they return to the moist earth and may or may not emerge again late in the day. They also spend the night in these haunts and just like baby box turtles, they may even find food where they are hiding. This makes it possible for them to stay hidden the majority of the time all while being in the presence of that precious moisture. Above is an example of a properly raised eastern box turtle (Terrapene carolina carolina). Its shell is strong, notably arched and smooth.
Taking a look at the photo to the left, you'll notice two adult Texas tortoises (Gopherus berlandieri) and this is a good example of a "not so bad" outcome. The animal up to the right is a perfectly and smoothly grown female while the male in the left foreground exhibits a degree of deformation which is especially noted when we look at the vertebral scutes. Instead of displaying a smooth arch, the top of his carapace dips down in the middle and is lumpy. Despite his appearance, he lives an otherwise normal life. The animal was initially a victim of an overly dry environment but this was then corrected by the keeper before too much damage occurred. He is lucky because when it comes to hatchlings, failure can happen almost overnight when they are kept too dry. Once babies start on a downward spiral, it's nearly impossible to bring them back.
Some tortoises will feature a "natural" degree of pyramiding. We see this most often in star tortoises (Geochelone elegans) and leopard tortoises (Stigmochelys pardalis). In their native lands, they are often subjects of extremely dry conditions for prolonged periods. This results in the slight raising of the scutes, primarily the vertebral scutes. It's possible that this varies from year to year. Some specimens that are exposed to an excessively dry year while they are still developing could be the reason behind why we also see perfectly smooth animals occurring in the same places. In nature, tortoises and terrestrial turtles drink from rain puddles, off vegetation or from standing bodies of water. They may even wade in it or even attempt to swim. The animals store the intake inside their bodies and void it if they are startled. This is one of the reasons why it can be a death sentence to a tortoise living in an arid or desert habitat if it is picked up and disturbed. By voiding it, they may dehydrate and perish if rains do not come again for a prolonged period.
In captivity, keepers often opt to soak their animals in warm water to ensure they are getting an appropriate amount of it. When kept outdoors, this is usually not necessary as they will take full advantage of rain and the puddles it creates within their enclosures. This adult radiated tortoise of ours wasted no time wading into a freshly created rain pool on a hot, humid day. Soaking is up for some debate as it is not really all that natural. Some people will do this every day which can have adverse effects. For one, picking the specimen(s) up to be soaked in a tub may cause them to void themselves. Instead of allowing the tortoise to store the water, they void it all only to drink it up again right away. This can be a possible issue if the animal is ever presented with a period of time where it will need its reserves. Secondly, soaking in warm water often forces the animal(s) to void their bowels. When this is constantly being done, who is to say that it won't be a problem down the line? No one picks up baby turtles and tortoises in the wild to soak them. They simply respond to the elements they're naturally presented with such as rain.
Rain holds so many benefits for these creatures and it helps to trigger responses in them which are timed with the seasons. Fall rains typically initiate the hatching of eggs in the ground that have remained buried for months. Spring rains signal a time to emerge from a winter's rest. This is when turtles and tortoises drink profusely to replenish themselves after months of inactivity. Even aquatic turtles will leave their watery expanses to travel in rain with some choosing to nest during or just after it. This adult male marginated tortoise (Testudo marginata) in the above photo is looking for a puddle during a light rain, early in the spring, after waking up from his brumation here. The point is, these are primitive reptiles with heavy instinct that is deeply seeded in their makeup. They know what to do and when to do it once we provide them with a naturalistic environment.
To touch on aquatic turtles again really quick, did you know that diamondback terrapins (Malaclemys terrapin ssp) will actually leave the water when it rains to drink from the fresh puddles? We took the above photo at one of our study sites just after an amazing thunderstorm. This female drank and drank from those big puddles. Because they occur in brackish water, they actively seek-out fresh water to drink when the rain provides. They'll even drink fresh water off each other's backs or from the very surface of the brackish habitat they live in.
Soaking is sometimes necessary as it can help an animal to relieve itself of a build up of toxins and of course, anything that's done in moderation isn't usually cause for alarm. We may soak on the occasion but for the most part, we allow our turtles and tortoises to experience rain whether it's when they're outside or when they're inside and we provide them with an "artificial rain" via misters or hoses. We also make sure they always have access to a shallow, clean water dish. This allows them to wade or soak and of course drink whenever they want. Remember, just because you're not seeing the animal in the act of drinking doesn't mean they aren't doing it. Why? well, to quote Olaf in Disney's Frozen 2, "Turtles breathe through their butts." It's true....they are taking the water in through their cloacas! I have 2 little girls and a wife who eats, drinks and sleeps Disney, so, you're welcome for that.
To sum it up, always keep it in the forefront of your mind that moisture and hydration play a critical role in the health of turtles and tortoises. The substrate should be deep and retain moisture especially when the air humidity is low. The animals should always have access to a water dish that is cleaned frequently. If you're going to soak, space it out. I'd suggest no more than two times weekly if you're otherwise providing an environment with adequate hydration. Keeping them outdoors at least for a few months during the summer hold benefits that cannot be replaced by indoor methods so by all means, allow them to experience it if you're able to offer them a predator safe, escape proof, naturalistic enclosure. Need some ideas? Check us out on YouTube to see how we do it here.
Stay tuned for the next blog and Happy New Year!