The Leopard Tortoise

It seems that people tend to name animals by their spots, if they have them; Leopard toad, Leopard tortoise ….

A game ranger once related the tale of how he took some naïve tourists on a game drive and, on spotting a Leopard tortoise explained that it is so named because it drags its prey up into trees. “Really?” asked one fascinated tourist. This story is probably apocryphal, but it makes me smile every time I think of it.

Photo: Zoo Med Laboratories

So what do we know (for a fact) about the Leopard Tortoise?

The genus name Stigmochelys is a combination of the Greek words stigma meaning ‘marked’ and chelone meaning ‘tortoise’. The specific epithet pardalis is derived from the Greek word pardos meaning ‘spotted’ after the blotchy shell. The descriptive Afrikaans name for it is “Bergskilpad”, or mountain tortoise.

We tend to think of tortoises as being uniquely African in origin, but in fact tortoises originated in Asia and entered Africa after spreading to Europe and North America. They are widespread throughout the savannahs of Africa, from southern Sudan, Ethiopia and Somalia southward through East Africa to the Eastern Cape and Karoo, and westward to southern Angola and Namibia. They are restricted to arid areas with some water sources. Some of these animals were translocated by people, released, and managed to survive, and are now found in areas such as the southwestern Cape and the former Transkei, adjacent KwaZulu-Natal and Lesotho, from which they were historically absent.

When translocated from their homes, both sexes are known to undertake long return journeys of up to 50 km. Home range size varies considerably according to the availability of food and shelter.

The Leopard Tortoise is the largest species of South African tortoises. They can live up to an age of 100 years in the wild, but life in captivity is considerably shorter, mainly due to malnutrition caused by the wrong diet. Overfeeding tortoises with a high-protein diet is the main cause of death in captive tortoises. The natural diet includes a wide variety of plants, especially the native grasses, which contain the right nutrients derived from the soils of their natural habitats. They also eat succulents and fallen fruits (thus fulfilling an ecological role of dispersing the seeds). Being toothless, tortoises shear through succulent grass with the aid of their sharp horny beaks.

Contrary to popular belief, tortoises need to drink water and do so when it is available. Tortoises are able to survive in very dry conditions by storing water obtained from succulent plants. They store the water in a cloacal bursa or sack in the rear of the body for use when required. They will also excrete this water supply as a defence against predators and to dampen dry soil when digging holes in which to lay eggs. If you pick up a tortoise trying to survive in very dry conditions it may excrete its valuable water supply, resulting in the eventual death of the animal.

Females grow faster and are considerably larger than males. In the breeding season, males are combative, as is the case for many tortoises. Combat includes bouts of competitor ramming, butting and sometimes overturning one another. The victorious male has a direct approach to courtship. It trails the female for some distance and repeatedly butts her. “Hey, you! How about a little whoopee?” Eventually he wears her down and she accepts his advances. The male’s concave plastron (belly shell) makes mounting easier.

Copulation is a noisy affair, even in tortoises. It is often accompanied by grunts, groans, gasps and wheezes from the male.

The gravid (pregnant) female takes great care in selecting a sunny, well-drained site to start digging a pit with her hind feet in which to lay her eggs. If the ground is too hard, she releases some of her precious urine or cloacal water to wetten and soften the ground.

Depending on the size of the female, she may lay up to 24 eggs in the hole. The eggs are white, round and hard-shelled. After egg-laying is complete, she refills the hole, which she pats down firmly with her hind feet. She then tamps down the soil by lifting and dropping her shell on the spot – a bit like failed push-ups.

Sadly, very few (only around 2%) of the eggs that hatch eventually survive to breeding age. Predators of the hatchlings and juveniles include rock monitors, storks, crows and small carnivores. In their natural habitat, falls in rocky areas may result in cracked shells, while others are scarred or killed by veld fires.

Apart from its spots, this tortoise can be recognised by its distinctly domed shell. This is an adaptation to hot arid conditions, where the sun beats down relentlessly. A curved shape reduces the sun’s direct impact at any one time. The “pyramiding” or growth of conical protuberances on the shells of some tortoises, is an indication of poor nutrition and is often seen in captive animals.

All tortoises are protected by law in South Africa and they may not be killed, captured or kept in captivity. The only reason to pick one up would be to remove it to a place of safety from a position where it was unlikely to survive – e.g. from a busy road or from the threat of an approaching fire. If picked up, the animal should be released as near as possible to the place it was located. In the Cape, especially, where species distribution is limited by habitat, untold harm will be done by releasing the captured animal into the distribution area of another species, or where it may not have the correct food plants. South Africa is thought to be home to 30% of the world’s remaining tortoises, but sadly, many tortoises are still captured for the pot or the pet trade, making them an increasingly vanishing species.