Welcome to Central Texas Tortoise Rescue’s Keeper Education series, which has been made possible through the hard work of our volunteers and with generous support from the Jacob & Terese Hershey Foundation.
Many chelonian species enter a period of dormancy when their metabolism slows and allows them to conserve energy during the cold season. This dormant period is known as brumation, and is part of a natural and healthy cycle for species that live in areas that experience real and sometimes intense seasonal fluctuations in temperature, photoperiod, and food availability. Semi-arid and tropical species, like sulcatas, leopard tortoises, and red and yellow-footed tortoises, do NOT brumate in the wild and thus when those species are held in captivity in more temperate climates, they require access to heated housing during the cold season. As a chelonian keeper, it is up to you to know what species of tortoise you have and whether or not that species experiences brumation in the wild so that you can provide the appropriate habitat components to keep your animal happy and healthy.
If you have a non-brumating tortoise species, you’ll need to provide a heated, insulated house for your tortoise to use any time outdoor temperatures drop below 60 degrees. Larger animals can withstand temperatures in the 50s, and many tortoises will even come out and graze on sunny days that are in the 40s or lower. At CTTR, if we know overnight temperatures will be between 50 and 60 we don’t stress about adult tortoises being left out overnight - although they still have access to heated housing should they choose to utilize it. If we know overnight temperatures will drop below 40, we walk around at dusk and make sure everybody has properly put themselves to bed, and manually put tortoises away if they’ve fallen asleep elsewhere.
Our favorite pre-made insulated houses are called Lifesaver Dog Houses. You can order them online and add supplemental heat so they stay nice and toasty on the coldest of winter days. As a bonus, the heavy insulation keeps the inside of the house cool in the summer and provides a nice reprieve from the Texas heat.
You can insulate a premade doghouse or if you’re handy you can build your own insulated dog house from scratch. If you’re not handy...well, that’s what they make YouTube for! Some people use a barn stall or cut an access door into their shed and heat the shed.
Here’s a video on how to build your own insulated dog house:
My younger brother is in his early 20s at the time of this video and runs his own handyman service if you are located near Austin and prefer to hire the work done: call or text JR at (512) 965-4398
Turtles and tortoises are ectothermic. That means they do not produce their own heat like a mammal, and they thermoregulate by moving into the shade when it’s hot or by basking in the sun when it’s cold. Heat mats, heat panels, or ceramic heaters can be used to heat your tortoise’s insulated house. It is important to mount these on the ceiling or wall of the house, rather than on the floor, and to manage the power cord in a way that the animal cannot become entangled in it. We discourage the use of heat lights in tortoise houses because the are fragile and a broken heat light can easily start a fire.
In humans, the nerve receptors that sense heat and pain communicate readily with one another, which is why we quickly draw our hand away from a too-hot surface. Reptiles do not have the same hot-pain withdrawal reflex, either because they haven’t evolved it due to not coming into contact with too-hot objects in the wild or simply because they reason differently than we do, and don’t associate the pain with the object that they are touching. It is for this reason that so many captive reptiles must be treated for burns. This is why heat mats must never be placed on the floor of your tortoise’s house, and is another reason why we discourage the use of heat lamps, which concentrate intense heat over a small area.
Take a deeper dive into thermodynamics and understanding how reptiles use heat here: https://ourreptileforum.com/community/threads/thermodynamics-the-importance-of-correct-heat-for-reptiles.2827/
It is our belief that animals thrive when cared for in the way that best mimics their natural habitat, and we encourage every tortoise keeper to learn as much as they can about how their animal lives in the wild. This information should guide any action you take in caring for your tortoise. We hope to develop additional courses that delve into the ecology of the species we see the most, but at the time of this course’s launch we haven’t done that yet.
You can monitor the temperature and humidity in your tortoise’s house with fairly small, fairly affordable technology. There are small, inexpensive ones and more complex ones you can monitor on a Bluetooth device such as a phone or tablet. While some models illustrated here have a read out display on the device, we’ve recently enjoyed using Kestrel Drops, which is a small device that you link to your cell phone over bluetooth, and can monitor both temperature and humidity from a distance. These can even log temperature over long periods of time so you can track how hot your tortoise’s home gets during the day and how cold it gets at night, and you can easily gather cyclical data to experiment with different configurations and settings for your heating arrangement.
In the wild, many tortoises use the bathroom in their burrow, and they’ll “nest” in their own excrement inside of their winter house, too. You can add non-colored mulch in the bottom of the house to soak up some of the liquid waste and to provide additional insulation. Using pine or cedar shavings meant for small mammals may irritate the tortoise’s eyes and respiratory system, and using straw or hay can be a fire hazard if too much is used. A blanket on the floor is not advised; however, a blanket or other extra insulation thrown over the top of the house to help prevent heat escaping through the cracks may be a good idea on especially chilly days.
Clear flaps help keep the heat in while allowing the tortoise to see out and to come and go as he pleases. These flaps are made of clear plastic car mats cut into strips. It’s a straightforward process to “train” your tortoise to use its house. Tortoises are diurnal, which means they are active during the day and sleep at night. At dusk, put your tortoise in its house. In the morning it will see the light coming through the door and will push its way out through the clear flap. You may have to put your tortoise to bed several evenings in a row, but eventually it will put itself away reliably each night. The longest it has ever taken us to train a tortoise to go to bed properly at night was about two weeks.
In February 2021, many of us faced unprecedented weather for the area in the form of a prolonged period of freezing temperatures. Before you decide to provide a home for a tortoise, make sure that you have both the financial and the physical resources and physical strength/fitness to be prepared for the unexpected. Once things freeze in Texas, it’s already too late to go buy a heater or generator. We recommend having a generator on hand to keep your tortoise’s house warm in case of long periods without electricity. You need to be physically capable of moving your tortoise to safety - either to their heated house or into your home with you if need be. We used every available container to keep tortoises gathered around our fireplace during snowpocolypse, except for one 80 lb tortoise that was outside in an insulated house with a heat mat connected to a generator. We used a bluetooth thermometer with an alarm on it to tell us when the temperature in the tortoise house dropped to 60, and then we’d crank on the generator to get it warmed up. We couldn’t leave for gas because the roads were impassable and most places were closed anyway, so we would leave the generator on long enough to bring the tortoise’s house up to about 80 degrees and then shut it off until the alarm went off again (about every 2 hours).
When temperatures are going to be too low for days at a time, we use plywood and bricks to block the doors to the tortoise houses so they can’t come out and get chilled and become stranded (cold-stunned, essentially) outside of their heated house. Generally, if the forecast is below 55 for several days in a row, we leave the tortoises “locked in” to their heated houses until the temperatures come back up. Once it warms and the sun comes out, we remove the blockade from the door and allow them to come out on their own. In our area they generally are not blocked in for longer than 2 – 3 days at one time, and even that happens very rarely.
Thank you so much for taking the time to learn about winter housing for your tortoise! Central Texas Tortoise Rescue is run completely by volunteers with no paid staff, and we have been able to obtain heated housing for our animals and to provide educational content for you thanks to your generous support and a grant from the Jacob & Terese Hershey Foundation. If you found this content useful, please share it with all of your tortoise-keeping friends, and if you’d like to support our efforts of course donations are always appreciated. Finally, if you have additional questions about heated housing for your tortoise please reach out and ask – we’d love to keep improving the content of this course and making it even better for you!