Tortoises Need Heat and Light

Posted at 2:09 pm August 16, 2010 by Rachel Foster

This healthy desert tortoise enjoys the warm sun.

We are reaching the mid-point of our second season here at the San Diego Zoo Desert Tortoise Conservation Center in Las Vegas, and we are seeing an increase in the number of pet desert tortoises surrendered to the Pet Tortoise Hotline (702-488-9422), exactly what we were hoping for! However, a large number of these pet tortoises arrive with a number of different health issues, most resulting from improper housing and diet. These can lead to a number of different conditions ranging from upper respiratory conditions to metabolic bone disease.

Since the entire shell of a tortoise is made up of bone and keratin, it is very important to feed them foods high in calcium to maintain the shell’s rigidity. As tortoises bask in the sun, they are not only soaking up the UV rays needed for calcium metabolism, but they are also warming themselves so that they can properly digest their food. Without the heat, even if they are eating, they are not digesting or getting the nutrients they need.

Rachel examines a tortoise at the Center.

In one case we saw this year, three tortoises were surrendered to the hotline. They had been living in an aquarium without any heat or light and were fed lettuce for several years before finally being surrendered. By the time they came to us, their condition was so severe that they were only barely alive. Their shells were flat and so soft that they bent inward with the most gentle touch. In addition, their beaks didn’t develop properly, they had severe edema all over their bodies, and they were very ill. These conditions are the direct result of nothing more than the tortoises being housed indoors and not being fed properly.

In another case, a tortoise came to us severely emaciated with old dog bite wounds all over her carapace (see a post about this problem: Family Dog Loves Pet Tortoise Too Much?). Because the family dog kept trying to use her as a chew toy, she was kept in a closet without heat or light where she was fed lettuce and fruit (not ideal for tortoises). Today, that tortoise is emaciated because, even though she was given food, she was unable to digest it without heat and light. She is just one of a number of tortoises we are rehabilitating so that some day they will be healthy enough to be released to the wild where they will contribute to the recovery of wild populations.

Rachel Foster is a research associate at the San Diego Zoo Desert Tortoise Conservation Center.

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8 Responses to “Tortoises Need Heat and Light”

  1. Shirley Sykes says:

    These are such sad cases, Rachel. You and your comrades at the SDZDTCC are doing a marvelous job in educating the public about taking care of tortoises, and in rehabilitating them. Many thanks to you all!

  2. Susan O says:

    These stories about the tortoises are as touching as they are informative. I look forward to learning more!

  3. Dianna from Ohio says:

    I always wonder what people are thinking when they do stuff like this.. and not only to tortoises but all pets… Alot of caring for a pet is just pure logic but it seems to skip some humans. The tortoises are very lucky to have you and your coworkers looking out for them.

  4. Mae was from NJ says:

    This makes me feeling like yelling and asking the people who have ignorantly handled them: WHY do you even think of having a tortoise if you just going to keep it in a closet???? I only hope more misguided people hear about your group and surrender these reptiles to you, and hopefully, in time for them to be returned to health.

  5. Lee says:

    I’m worried about my desert tortoise hatchling. He is 3 weeks old and is being raised initially in a large terrarium. We are using the UV light that best matches sunlight. He is active and we are feeding him dandelion, weeds, grasses, hibiscus, grape leaves and greens dusted with Reptivite.

    The little guy is very active and is eating well. It is raining hard today and I cannot imagine him living outside for his first year. Is this an acceptable environment for his first year?

  6. DCTT Team says:

    #5 Lee

    The most important thing you can do for your hatchling is to let him live outside. I know it’s hard to think that this little fragile life can do well out there, but hatchlings that are not allowed to hibernate, especially in their first year of life, are less likely to grow up healthy. There is no light bulb in the world that will provide the exact amount of desert UV light and heat that a desert tortoise needs. (Are you using a desert-specific bulb that also provides heat? UV bulbs only last six months to a year giving off the UV rays they claim to have, so be sure to change it regularly). If your hatchling just hatched three weeks ago, then it should not be eating – they hatch with their yolk still attached, and most live off of that nutrition until the following spring when they come out of hibernation. He should have a drink, but nothing more. If you have already fed him and he actually ate, then you should not allow him to hibernate, because tortoises should not go into hibernation with food in their GI tract. Also, you might want to check the Reptivite to see if it is appropriate for desert tortoises – different reptiles have very different nutritional needs, and desert tortoises in particular have very different needs from many other species. You don’t want to give your hatchling vitamins that he doesn’t need or that could be detrimental to him. You didn’t mention heat – do you have a heat lamp on the terrarium? Tortoises cannot digest their food unless they are housed at the proper temperature, so this will be critical during the winter inside your home. Also, don’t forget about water – tortoises absolutely must be able to take in fresh water every week during the active season and when they are housed indoors temporarily, even in the off season.

    In my experience, hatchlings (and desert tortoises in general) that are housed indoors do not fare well in the long run. Most suffer from metabolic bone disease due to lack of proper heat and light, which leads to improper nutrition from being unable to digest their food. They may be alive, but they are not very healthy. It takes a long time, sometimes years, for a tortoise to begin to look or act sick, so by the time someone notices, it is often too late. Tortoises are a huge commitment, especially when they are young and tiny, so it will take a lot of effort on your part to make sure he’s healthy. Although it sounds like you won’t be able to hibernate him this year because he’s eating, the best thing you can do for him is to put him outside in the spring into a predator-proof enclosure with a well-constructed burrow that he can enlarge on his own as he grows, and commit to not bringing him inside any more after that. He can live to be over 100 years old if he is cared for properly, so I hope the spring will bring a great start to his life.

    If you decide that caring for him will be too difficult, and you live in southern Nevada, please call our hotline at 702-488-9422, and we will be happy to pick him up for free and bring him to the DTCC where he can live with other hatchlings and we can care for him in a protected area.

  7. Buslady says:

    Lee: If you need a safe outdoor enclosure look at Waterland tubs, these are made for turtles & tortoises (the small land version would do well for babies). I have one of these for my 4 turtles so they get their outside time when I’m home. You can make a screen top to put over it, your baby would have a large land area and a shallow water side to soak in.

    Keeping one outside 100% of the time can be dangerous if you have predators like raccoons and possum, so you’d bring him inside at night, outside in the tub at day. Keep feeding weeds and stuff, anything high in calcium. No broccoli, cabbage and related veggies…very bad stuff. No tomatoes.

    With my 4 babies, they’re 50/50 inside and outside. Two are adult size now, small species..lookin good…and the two I’m raising from day one are growing slow and steady. So it’s not a lost cause, the biggest thing is slow growth and avoid pyramiding (stacking of the scutes)

    (for the record are all captive bred, 2 hatched here(CA Ornate wood), one turns 4yrs tomorrow! The other two is a Reeves, and a Spotted.)

    Desert Tortoise Team responds: We see you have turtles, not tortoises, Buslady. It is never safe to keep tortoises outside without having access to a burrow or burrow-like structure, since desert tortoises are so sensitive to temperature, and they certainly need to be in predator-proof enclosures, and we don’t think a simple screen over the top will discourage a determined predator.

  8. johnthan says:

    Most reptiles require high quality and appropriate lighting to meet a number of different metabolic needs. The only exceptions are certain nocturnal and dense rain forest species. It is not necessarily the case that all of these needs can be accommodated by one single form of lighting.