Tortoises live around the world in a wide variety of habitats, from temperate forests to harsh, arid deserts. Simply put, tortoises eat plants. Most species have evolved to consume the flora in their local ecosystem and adapt as needed to seasonal changes. If you have a pet tortoise, its essential to feed it a diet close to what it would eat in the wild.

The difference between turtles and tortoises can depend on the context of the conversation. In casual conversation involving non-experts, Americans tend to use the word "tortoise" to refer to land-dwelling, shelled reptiles and "turtle" to refer to a shelled reptile with webbed feet that spends most of its life in water. British people tend to use the world "turtle" to refer only to marine shelled reptiles, known to Americans as "sea turtles." To zoologists, both are considered chelonians, because they are in the taxonomic order called Chelonia, which is Greek for tortoise.

Tortoises inhabit forests around the world and their eating habits are heavily influenced by the local climate and seasonal variations. Leopard tortoises living in Tanzania have been observed eating mostly fleshy succulents (51 percent), with some grasses (almost 17 percent) and legumes (nearly 14 percent). Angulate tortoises living in a wide range of habitats along the southern and western coasts of South Africa heavily modify their diet based on the seasons. During the wet season, tortoises were observed eating grasses, shrubs, herbs and succulents. During the dry season, the tortoises were seen foraging for dry plant material and supplementing their diet with rabbit feces.

Desert tortoises are native to the American Southwest and these reptiles are completely herbivorous. Their diet includes mostly desert grasses, leafy plants and flowers. Some people keep these tortoises as pets and many make the mistake of indiscriminately feeding them store-bought produce. While store-bought produce can be part of a desert tortoise's diet, it should be limited to dark leafy greens that are high in fiber -- such as kale, collard greens, spinach and parsley.

Some people make the mistake of feeding their pet tortoise fruits and a tortoise may readily accept these sweet-smelling offerings. However, fruits contain too much sugar for a tortoise and a high-sugar diet can impair the reptile's organ function over the long term. Variety should be the cornerstone of any pet tortoise's diet. Their preferred food of leafy greens may seem boring to us but there is a lot of variety within that seemingly narrow category. With a hard, bony exterior and females that lay eggs, it should come as no surprise that tortoises also need a lot of calcium in their diet. This can be included in the form of prickly pear cactus pads or collard greens.