We all know that maintaining a consistent temperature gradient in a tortoise enclosure is critical. Being cold blooded means that tortoises are unable to maintain their own body temperature independent of the world around them, therefore having a strong heat source to bask under is critical for them to be able to carry out key metabolic functions such as digestion of food and the absorption of calcium.
It’s well known how to maintain the right temperatures during the day, either with the aid of sunlight or a heat bulb, but what are the requirements for temperature during the night?
Does a Tortoise Need a Heat Lamp at Night?
Whether or not your tortoise requires additional heat at night is dependant on several factors, including the ambient temperature of your house or yard (depending on where you keep them), and the species, as some are more resilient to lower temperatures than others.
If night time heat is required however, I would certainly advise against it coming from a light bulb. Just as they would in the wild, tortoises require darkness in order to sleep properly.
Therefore if you do require a source of additional heat at night, I would opt for another method such as a ceramic heat emitter, or a heat mat.
How Should I keep a Tortoise Warm at Night?
Ceramic Heat Emitters & Heat Mats
Whichever method of heat you choose, you should be sure that it doesn’t produce more heat than is necessary, especially given that the temperature should almost certainly be cooler than during the day.
For this reason heat mats are in many ways the better option as they often feature a built in thermostat that you can easily adjust.
To be able to adjust the temperature of a ceramic heat emitter may require an additional thermostat which isn’t as easy to set up, as well as being an additional cost consideration.
Which Species of Tortoise Require Additional Heat at Night?
When it comes to all living things Mother Nature usually knows best, or at the very least she knows what works.
We can determine what night time temperature is required by a particular species by looking at the average night time temperatures in the areas of the world they hail from.
Testudo Genus Tortoises at Night?
The group of tortoises that fall under the Testudo genus (Hermann’s Tortoise, Greek or Spur Thigh Tortoise, Russian Tortoise, Marginated Tortoise, and Egyption Tortoise) all live in or just outside of the Sub Tropical regions of southern Europe, The Middle East and North Africa.
During the warmest months of the year these regions are usually 18 °C (64.4 °F) to 20 °C (68 °F). This sort of temperature correlates fairly well with night time room temperatures throughout Europe and North America, so for tortoises kept indoors this is fairly easy to achieve and maintain.
As for outdoor living at night, it’s not necessarily that these species can’t survive at lower temperatures throughout the year, as they’re able to slip into a semi hibernative state should they need to when temperatures drop outside.
However the closer you can get to matching their natural environment the more healthy their growth and development will be, so it’s advisable to both monitor and supplement the temperature should you need to. This is especially likely outside during the spring, autumn and winter.
When it gets really cold (close to 0 °C for example) it’s necessary to bring your tortoise indoors, either for overwintering or hibernation.
Whilst the specific environmental requirements for tortoise’s that hail from the tropics varies between those from the humid rainforests of South America to the semi arid grasslands of central Africa, one thing that more or less unites them is the greater temperatures they are exposed to all year round.
Tropical tortoises include Red Foot tortoises, Yellow Foot tortoises, and Indian Star Tortoises. These vary in their resilience to temperature, with the Red Foot Tortoise in particular being more adaptable to slightly lower temperatures, and the Indian Star Tortoise being notoriously prone to illness due to low temperatures and excess humidity.
Tropical regions generally don’t generally experience night time temperatures below 22 °C (71.6 °F), so there is a need for tropical tortoises to be kept slightly warmer during the night than mediterranean/north African tortoises.
Crucially of course Tropical tortoises don’t hibernate, no bringing them indoors to be overwintered when outdoor temperatures drop below 13 °C (55.4 °F) is essential regardless of whether you have additional heating facilities outside or not, it’s not worth the risk.
If my Tortoise Lives Outside Do I Need an Additional Night Time Heat Source?
When it’s not time for hibernation or overwintering and your species can safely be kept at lower temperatures you might still want to provide additional heat for them at night, not because it would be fatal if you didn’t, but because it might promote better overall health and reduce the potential for respiratory infections and other unwanted problems.
If you’ve got visions of having to rig up electric heaters and lamps outdoors and all the headaches (not to mention ongoing costs) of having to do so, the good news there is a simple alternative method that doesn’t require any complicated wiring or even a power source.
There are several good outdoor enclosures on the market that are essentially just like small greenhouses that trap heat from the daytime sun.
I would choose a model that has a swing door that can be locked in the evening, keeping both the tortoise and heat in, and don’t forget to monitor the temperature inside the enclosure with a thermometer.
Whilst this type of enclosure won’t be effective enough to keep your tortoise outside during very low temperatures, it will almost certainly extend the portion of the year when you can keep your tortoise outdoors full time.
Should Outdoor Tortoises Be Brought Inside During Winter?
I have known people to keep their tortoises outside all year come rain, shine, or indeed snow and frost. Whilst they might take pride in this, to me it represents nothing short of stupidity, not to mention animal cruelty.
Why you would choose to play russian roulette with your tortoise’s life in this way is beyond me, so I would always strongly advocate bringing your tortoise indoors for the winter regardless of the species.