Reptiles and amphibians: tortoises, terrapins and turtles

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Tortoises, terrapins and turtles, also called chelonians, are long-lived reptiles characterised by their protective shells, which often have beautiful carapaces, or upper parts. Their shells have long been admired by humans, and this can be the chelonian's undoing, since some humans value the shell more than the live animal. The carapace and plastron (lower part of the shell) allow the chelonian to hide from predators, so it can escape without having to run.

Mediterranean tortoises were once imported in large numbers and left to roam free in British gardens, where they didn't always survive the winter. They're now rarer and are valued more, so the standard of care has improved. Tortoises may not be as high-maintenance as some reptiles, but still need careful looking after, especially when they come up to hibernation. Aquatic and semi-aquatic chelonians are more high-maintenance, and particular care is needed to ensure that their water is clean and at the right temperature.

Tortoises can live longer than most humans, while red-eared terrapins can live for 30 years, but both are relatively easy to rehome compared to some reptiles, such as large snakes and lizards! The main concern when choosing a specimen is to find one that is healthy, old enough to survive without special nursing, and which has not been caught in the wild. Reputable reptile specialists are the safest bet for buying healthy chelonians, or you could try a fellow reptile enthusiast whom you can trust. Reputable specialists can also provide advice on whether a particular species is suitable for you, and on care and equipment.

Chelonian behaviour

Perhaps the best-known characteristic of chelonians is their habit of withdrawing into their shells when they feel threatened. This tends to deter animals that might want to eat them, so chelonians don't have to run fast to get away, and tend to be slow moving. They're also mostly vegetarian, so don't need to chase prey, though some aquatic species are carnivores, and can snap fast. 

Chelonians tend not to parent their offspring, and most are solitary animals. However, research on red-footed tortoises has shown that they can learn how to perform a task by watching another tortoise, which is a curious talent in a solitary animal that normally lives alone. The research was carried out by a team led by Anna Wilkinson, who also discovered that red-foorws tortoises aren't affected by contagious yawning in the way that humans, and other social species are. This study won her an Ig prize for improbable research.

Chelonians 'think' better when it's warmer, and slow down in both movement and their ability to react to what's happening around them when it's too cold for them. If you think your chelonian is too slow, check that you're providing enough warmth. 

Housing and environment

Chelonians are cold-blooded, so they cannot regulate their temperatures except by moving to somewhere where it's warmer or cooler. Most species kept as pets come from areas with warm climates, so they need heating, if only in the colder months, from a heat pad and/or other source. They also benefit from temperature variations so that it's cooler at night, as happens in the wild, and they need access to sunlight and/or have special lamps. Species from tropical and semi-tropical climates have a special need for artificial light in Britain. They can also burn easily, so use a thermostat and more than one thermometer to control and monitor temperature variations in different parts of the vivarium.

Tortoises and terrapins like to bask, though you need to keep a check to make sure it doesn't get too hot in their basking areas. Red-eared terrapins and tortoises need up to 30 deg C. Terrapins also need access to water, with a ramp or a slope, so they can go easily from water to land and back. Water temperatures should be at between 22 and 24 deg C. The background daytime temperature, ie not in the basking area directly under the bulb, should be around five to eight degrees cooler than the basking temperature, and the night-time temperature around five to eight degrees cooler than the background temperature in the day. This varies according to where the species comes from, however, and it helps to learn about the environment there, and to check the day-night temperature variations in the area(s) of origin, as well as variations between summer and winter. It's also worth checking seasonal changes in hours of daylight, especially for non-tropical species. There is little variation between summer and winter hours of daylight at the tropics, but much more variation as you move towards the cooler regions.

These changes in light and temperature are especially important for those chelonians that hibernate in winter. You need to adjust light and temperature, and reduce then stop giving food if you want to prepare your chelonian for hibernation. Chelonians from cooler parts of the world are more likely to hibernate, whereas those from tropical and semi-tropical regions tend to stay awake all year. Hibernating chelonians are vulnerable if left out of doors. They cannot survive frozen water, even if they are semi-aquatic species. Terrestrials can be given a box with insulating materials (like newspaper) to hibernate in, and left in a spare room, conservatory or unused garage. Fumes can harm them if the garage is in use for parking cars.

Chelonians found in deserts and other dry areas in the wild need a dry environment in captivity, though they can get dehydrated, and should of course always have access to water. Species from jungles and aquatic environments need more humidity, and are especially prone to dehydration if subjected to central heating, with no chance to moisten their skins. You can use a mister with tepid water to boost humidity levels.

All chelonians need access to drinking water, and some species also need to be able to swim. They aren't as sensitive as fish to chlorine, but still need dechlorinated water. Chelonians will both drink from, and defecate in their bathing water, so you need to check that it's clean, and change it regularly. Tortoises can't usually swim, so keep them away from deep water, but they do benefit from a bath in shallow, lukewarm water a couple of times a week, especially if they're kept indoors and you have central heating. Ideally, tortoises should have access to outdoors, especially in the daytime, except in very cold weather. If you have a largish greenhouse, and don't use pesticides or herbicides in it, a tortoise can enjoy being outside with some protection from the cold.

You can use mixed peat and sand, sand and birdgrit, wood chippings or newspaper for substrate (bedding) for dry land species, with some shady areas with damp moss for species needing humidity. Chelonians like to dig, and some species benefit from bird sand or grit, as a source of calcium. Do clean whatever you use regularly, and use filters to keep water clean for aquatic species.

The size of the vivarium is important. It should be big enough to allow your chelonian plenty of room to move around after it has grown, so check how big it will grow. The smaller the vivarium, the more often it will need cleaning, and the greater the risk of infection, so provide as much space as you can. Likewise, the more water an aquatic species has to swim in, the lower the risk of infection, and the less you need to change the water. 

Feeding

As a general rule, tortoises are mainly vegetarian, while terrapins and turtles are mainly carnivorous, though there are some semiaquatic species from the tortoise family which are omnivores. 

Vegetarians like Mediterranean tortoises, should eat mainly green foods like dandelion leaves, clover, turnip greens, Chinese lettuce, and clover, as well as carrots and squash. They can eat mushrooms, or chickpeas for protein, though protein levels should be kept low. A little wholemeal bread or grain with bran can be provided for fibre. Don't put butter on their bread, or give them cheese! Vegetarian tortoises can suffer from liver trouble if they eat saturated fats, and too much protein can also cause them serious problems. They can eat fruit, such as grapes, kiwi fruit, and oranges. Vegetarians should eat fruit very sparingly, though omnivores can tolerate it better. Feed brassicas, beets and celery only very sparingly, and not often.

Vegetarian tortoises should never be fed cat or dog food, which is too high in fat and protein, and which may not have the right ratio of calcium to phosphorous, so could affect their shells.

Carnivorous species can be fed live prey, such as mealworms, and small aquatic creatures, which they like to catch themselves. Care should be taken to ensure that dead food does not pollute water. They should be fed as much as they can eat, but not every day, three times a week is plenty.

Shell deformities and high mortality rates amongst hatchlings are common in animals fed on the wrong diet, and they may also grow too fast when they are young. Andy Highfield's work in this area is well worth reading, if you plan to keep members of the tortoise family (see Further reading).

Hibernating species need special care with their diets prior to hibernation. They need to build up reserves, but also slow down before they hibernate, because their digestive system is unable to cope with any remaining food once they're hibernating. Fruit can be a particular problem, since it ferments, which can be fatal for a hibernating chelonian.

Health

Diet and temperature are crucial. Make sure the food is fresh, and in the right proportions, removing stale food at least once a day, preferably twice. Avoid the temptation of feeding unsuitable human food titbits, like bits of chocolate and crisps, even if these are consumed avidly. The right temperature is important to avoid feeding and digestive problems. Don't let the temperature drop too much at night if your reptile seems to have respiratory problems. Cold, damp conditions can cause respiratory problems, especially in chelonians from arid regions, so it helps to keep a check on humidity.

You'll need to find a vet with an understanding of reptiles while your chelonian is healthy, since reptile vets aren't always easy to find in an emergency. Chelonians will need to see a vet if they're off their food for no clear reason (such as hibernation) and appear to be losing weight, wheeze or blow bubbles, pass blood in their stools, have deformed or damaged shells, apparent inflammations, or suffer damage due to attacks from other animals. Shells can suffer damage from falls or fungal infections, and may not grow properly if your chelonian isn't fed the right diet. A chelonian that is in pain will often grind its 'teeth' (actually, they don't have teeth as such, but beaks) and that is a sign to see a vet.

Hygiene helps to avoid infections, and frequent cleaning to remove rotting food and excrement will lessen risks of infection. Hygiene is very important if you have an aquatic species, because chelonians are prone to both fungal and bacterial infections. They're especially vulnerable if they have an open wound or a shell infection. Dirty water can both cause infections, and make them worse. If your chelonian has a wound (whether or not it looks infected) or any suspected infection, clean the tank daily, as well as keeping the water clean, both by changing it and of course by using a good filtration system. Do get help from a vet if your chelonian has a wound that takes longer than a few days to start healing. There could be an infection that you can't see, which may need antibiotics and other treatment.

 

Young chelonians and those that are underfed or have been ill with infections, wounds or for any other reason shouldn't be allowed to hibernate, nor should recently acquired specimens. You need to weigh your chelonian before hibernation and keep checking the weight. If this goes down sharply, warm the animal up and provide water. Chelonians can suffer from dehydration during hibernation, as well as damp Very dry skin, or a sunken appearance can indicate dehydration.. You can give your chelonian a shallow bath, before drying it and putting it back to bed. 

Female chelonians will sometimes become agitated, because they need to lay eggs. They need to be able to dig in order to do this, which is one reason for providing diggable substrate, or a digging area. They can lay eggs even if there is no male, though the eggs won't hatch.

Hygiene and handling

There are risks to humans from certain types of salmonella harboured by any reptiles. As a general rule, reptiles shouldn't be kept in households where the human inhabitants are very young or very old, so more susceptible to infection. Always wash your hands after handling reptiles. Don't keep them in the kitchen or dining area, or clean their housing in the kitchen - ideally, you should use an outside tap. If you have to use the bathroom to wash reptile equipment, disinfect the basin/bath with bleach afterwards.

Some chelonians are more likely to bite and are generally more aggressive than others, and if you're a novice, it is best to avoid these species. If you own a carnivorous chelonian, don't give it access to a finger, that could be mistaken for prey! As with all reptiles, try not to startle chelonians by making sudden movements close by that might appear threatening. Loud footsteps and vibrating floors can also spook them, so wear soft-soled shoes.

Give any new chelonian in your collection a chance to settle in and get used to you before you think of handling. In general, keep handling to a minimum. It may be tempting to pick up a creature with a beautiful shell, but it's stressful for the chelonian. If you do have to handle a chelonian, keep the head away from you, and keep lights dim and noise levels low, to minimise stress. Never turn a chelonian upside down. If you need to look underneath, lift it up, and look from below.

Breeding

Breeding is affected by seasonal variations, which you can mimic by adjusting the light and temperature. Chelonians that hibernate seem to need to do this in order to breed, while tropical species also seem to breed more readily if they've been relatively inactive for a few weeks. You can feed them less for a few weeks in order to encourage this period of inactivity, then feed more, and this 'stop and start' can stimulate breeding.

Hatchlings need special care with their diet to grow big and strong like their parents - the quality of the shell is especially affected by juvenile diet. Would-be breeders need to read up on chelonian nutrition and the needs of their particular species. As for how chelonians mate - well, you will just have to watch!

Further reading:

  • Ackerman, Lowell (1998) The Biology of Reptiles: Health Care, TFH Publications.
  • Ackerman, Lowell (1998) The Biology of Reptiles: Husbandry, TFH Publications.
  • Ackerman, Lowell (1998) The Biology, Husbandry and Health Care of Reptiles: The Biology of Reptiles, TFH Publications.
  • Bartlett, R.D. (1996) Turtles and Tortoises (A Complete Pet Owner's Manual), Barron's Educational Series.
  • Bartlett, R.D. (1999) Terrarium and Cage Construction and Care, Barron's.
  • Davies, Robert and Valerie Davies (1997) The Reptile and Amphibian Problem Solver: Practical and Expert Advice on Keeping Snakes, Lizards, Frogs and Other Reptiles and Amphibians Tetra Press; ISBN: 1564651940
  • Ferri, Vicenzo (2002) Turtles and Tortoises, Firefly Books Ltd.
  • Tim Halliday, Tim (Editor), and Kraig Adler (Editor) (2002) The New Encyclopedia of Reptiles and Amphibians Oxford University Press
  • Highfield, Andy (1994) The Tortoise Trust Guide to Tortoises and Turtles, Carapace Press.
  • Highfield, A.C. (1996) Practical Encyclopedia of Keeping and Breeding Tortoises and Freshwater Turtles, Carapace Press.
  • Highfield, A.C. (2000) The Tortoise and Turtle Feeding Manual, Carapace Press.
  • Klingenberg, Roger (1993) Understanding Reptile Parasites: a Basic Manual for Herpetoculturists & Veterinarians Advanced Vivarium Systems.
  • Kuchling, G. (1998) The Reproductive Biology of the Chelonia (Zoophysiology), Springer-Verlag Berlin and Heidelberg.
  • Mader, Douglas (1996) Reptile Medicine and Surgery, Saunders.
  • McArthur, Stuart (Editor) (1996) Veterinary Management of Tortoises and Turtles, Blackwell Science.
  • Orenstein, Ronald (2001) Survivors in Armor: Turtles, Tortoises and Terrapins, Key Porter Books.
  • Palika, Liz (2001) Turtles and Tortoises for Dummies, Hungry Minds.
  • Pursall, Brian (1994) Mediterranean Tortoises, TFH Publications.
  • Wilke, Hartmut (1998) Turtles and Tortoises (Family Pet Series), Barron's Educational Series.

  • Wilkinson, A., Kuenstner, K., Mueller, J., & Huber, L. (2010). Social learning in a non-social reptile (Geochelone carbonaria) Biology Letters, 6 (5), 614-616 DOI: 10.1098/rsbl.2010.0092.

  • Wilkinson, A, Sebanz, N., Mandl, I., Huber, L. (2011) No evidence of contagious yawning in the red-footed tortoise Geochelone carbonaria Current Zoology(formerly Acta Zoologica Sinica), 2011, 57(4): 477 - 484

  • Warwick, C., Arena, P., Lindley, S., Jessop, M., and Steedman, C., (2013) Assessing reptile welfare using behavioural criteria. In Practice 2013;35:123-131 doi:10.1136/inp.f1197
  • Zug, George, Vitt, Laurie J, and Janalee P. Caldwell (2001) Herpetology: An Introductory Biology of Amphibians and Reptiles, Academic Press.

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