Feeding Mediterranean Tortoises - Some Basic Guidelines for a Healthy Diet

A. C. Highfield

The diet of Mediterranean tortoises in the wild consists almost entirely of herbaceous and succulent vegetation, including grasses, flowers, twigs and very occasionally fallen fruit.

During episodes of rainfall the tortoise will drink from the puddles which form, and it may also approach streams or ponds. It will frequently also pass urine at this time as well, and will simultaneously dispose of the chalky white uric acid residues which form in the bladder. It is categorically not true that wild tortoises rarely drink. I have seen both Testudo ibera in Turkey, and Testudo graeca graeca in Morocco approach streams and ponds and drink copiously, in addition to regular observations of drinking following rain. During the dry season, and in the more arid parts of their range, tortoises rely mainly upon the water content of their food in order to supply their moisture requirements. In captivity, we suggest soaking the tortoise for 10 minutes twice each week in fresh, shallow water to ensure an adequate state of hydration.

In captivity, a high fiber, low protein and calcium rich diet will ensure good digestive tract function and smooth shell growth. Mediterranean tortoises fed on cat or dog food, or other high protein food items such as peas or beans, frequently die from renal failure or from impacted bladder stones of solidified urates. Peas and beans are also very high in phytic acid, which, like oxalic acid, inhibits calcium uptake. Avoid reliance upon ‘supermarket’ greens and fruits which typically contain inadequate fiber levels, excessive pesticide residues, and are too rich in sugar. Fruit should be given very sparingly or not at all as it frequently leads to diarrhea, intestinal parasite proliferation, and colic.

When planning a diet for captive tortoises, take their natural dietary behavior into account as fully as possible. In the case of Mediterranean tortoises, try to provide a mixture of edible grasses and clovers, supplemented by mulberry leaves, grape leaves, and hibiscus leaves and flowers. Opuntia cactus pads are a great favorite and are rich in both calcium and fiber. A lack of dietary fiber, or roughage, will precipitate digestive tract disturbance, diarrhea and an apparently much increased susceptibility to flagellate and worm problems.

Although Mediterranean tortoises will take animal protein if offered (as will most normally herbivorous tortoises), in practice this leads to excessive growth and causes severe shell deformities, liver disease, and renal stress. It should therefore be avoided entirely. In our experience, tortoises that are fed animal protein suffer premature mortality.

A balanced diet for Mediterranean tortoises can also  include dandelion, naturally occurring non-toxic weeds, white (Dutch) clover (in moderation, it is quite high in protein), both leaves and flowers, rose leaves and petals, and sow-thistle, romaine or red leaf lettuce (in very limited quantities). Do not use head lettuces such as iceberg, as these contain very little in the way of vitamins or minerals.

Most land tortoises can and do fare best  when allowed to graze, offering the other listed items as occasional supplements. Do not routinely offer cabbage, spinach, chard, bok choy, or any vegetable related to these, as they inhibit calcium absorption and can cause serious health problems. This is particularly critical in the case of juveniles or egg-laying females. The regular use of a cuttlefish bone left in the enclosures allows tortoises to regulate the amount of calcium in the diet. Some tortoises like this very much, while others will refuse to eat it. Allowing Mediterranean tortoises to forage and graze naturally actually helps the tortoise to maintain good digestive-tract health, and greatly assists in the prevention of obesity. If scute pyramiding is noted, this usually indicates that either too much of the ‘right’ type of food is being consumed, or, more likely, that the overall protein content of the diet is too high. We recommend the use of a good quality phosphorus free calcium and vitamin D3 supplement at least twice per week, more frequently for juveniles and egg-laying females.

A. C. Highfield