Tortoise, Pancake


Malacochersus tornieri


The pancake tortoise has a very flat, flexible shell, which can be bent and depressed with only mild pressure. While the shell bones of most other tortoises are solid, the pancake tortoise has shell bones with many openings. Their carapace is brown with a random pattern of radiating lines on each scute, which allows the tortoise to blend into its environment. There are twelve pairs of marginal scutes and two supracaudals (the shell scutes above the tail). Their beak is moderately hooked and the upper head scales are small and irregular. Their longer and thicker tails in comparison to females can identify males. Pancake tortoises are small and typically reach a carapace length of about 6 inches and weigh about 1 pound. The size of the largest male carapace is a
little over 6 inches and female’s carapace is 7 inches; height is about 1.5 inches.

Family

Testudinidae

Order

Testudines

Class

Reptilia

Range

Parts of Kenya and Tanzania, including the Serengeti National Park in East Africa.

Habitat

Rocky hillsides (known as kopjes) at elevations of 100-6000 feet.

Life Expectancy

In captivity, some individuals have been kept for decades.

Sexual Maturity

Diet

In the wild, the available dry grasses and vegetation. In the zoo, they are offered various greens, hay and vegetables.

Status

IUCN - Vulnerable, CITES - Appendix II

Behaviors

During daylight hours, they spend their time in rock crevices. Their depressed shells enable them to push their way into these areas not accessible by their convex-shelled cousins. When suddenly surprised, they may be removed easily from these hiding spots; if warned by a shadow falling across the entrance, they inflate their lungs so that their shells press upon the rock both above and below as they brace their legs like struts. Large distances can separate suitable habitats of sufficient size to support a viable population of pancake tortoises. Within one habitat, however, tortoises coexist peacefully with multiple individuals sharing favored crevices. Even so, social status allows higher ranked animals to choose the more favorable locations within a crevice. The usual grouping found by Moll and Klemens was a male-female pair, but up to ten tortoises have been seen in one crevice. The data collected by the researchers indicate that males may move from crevice to crevice, while females tend to stay at a single location. However, although intriguing, this data is still preliminary. Moll and Klemens also noted that other reptiles were also found within the pancake tortoises’ homes in Tanzania. These included agamas, geckos, skinks, and plated lizards. Presumably these animals take advantage of the protection of cracks and crevices in the same manner as the pancake tortoises. Moll and Klemens found a number of pancake tortoises that had been killed. The most likely culprits were small predators such as mongooses.This tortoise possesses a diamond-shaped region on its plastron that is extremely flexible, moving out when the tortoise draws in its legs. The combination of these two defensive maneuvers renders pancake tortoises virtually immovable when determined to stay put. Grasses and vegetation constitute the majority of the diet of a pancake tortoise. The exact food is dependent upon which species grow in the area and on the season of the year. Plants included in their diet include star grass, red oat grass, aloe, seeds and nuts. Standing water is rare in the kopjes except during the rainy season. Presumably during the rest of the year, the vegetation upon which the tortoises feed provides an adequate supply of water. In order to eat Pancake tortoises must leave the safety of their crevices. Tortoises in Tanzania were seen outside their crevices at many different times during the day, spending approximately one half hour each time foraging and occasionally resting. Other researchers have reported pancake tortoises basking or moving about in search of food. With its flat shell, soft plastron and habit of fleeing rather than withdrawing into its shell when disturbed, the pancake tortoise (Malacochersus tornieri) rates as one of the oddest of all chelonians. Courtship occurs throughout the year but is particularly frequent during the spring and early summer. Compared to other species, the courtship does not seem to be particularly sophisticated in pancake tortoises. The male will chase down a female and then mount her. If unsuccessful in chasing down the female, the large male will attempt to mount one of the smaller males, and occasional scuffles will break out. However, these are of a short duration and do not usually involve pursuit, biting or physical injury. Mating occurs at the beginning of the year, with nesting in July and August. Females will usually lay only a single egg and bury the egg under 3-4 inches of loose, sandy dirt. One female can lay multiple eggs over the course of a single season, with eggs appearing every 6 weeks to 2 months. The incubation period lasts about 4-6 months. Young hatchlings are about 1-1 1/2 inches long and more circular than adults. They are dark yellow, with brown or black markings on the scutes, plastron, and carapace. In captivity tortoises will mate year-round, but breeding success can be increased by providing the pancake tortoises with a yearly light cycle in which the length of the day varies over the course of the year, similar to that provided for other turtles, snakes, and lizards. If two or more males are kept together, they will sometimes fight over the females, who tend to ignore the males unless the males are actively pursuing or circling them. Some breeders report increased success with larger groups of tortoises, as combat between males may stimulate mating and increase fertility. Although most females only lay one egg at a time, each one can produce multiple clutches with a six to eight week gap between layings. Eggs are approximately two inches long and one inch wide - surprisingly big relative to the size of the tortoise! Eggs are usually laid in sandy soil; in captivity, females will deposit eggs in out-of-the-way places in the cage if they find the nesting area unsuitable. Females that are producing eggs should have calcium and vitamin supplements added to their diet to allow for proper egg and embryo development and to prevent vitamin and calcium deficiencies in the adult. Hatchling pancake tortoises look like hatchlings of many other tortoise species. Typically, they are dark yellow, with brown or black markings on the scutes on both their plastron and carapace. Their carapace is even slightly domed, unlike that of their parents. Upon hatching, juvenile Pancake tortoises are about one and a half inches long, and more circular than adults. As they age, they gradually adopt the more normal rectangular shape of an adult pancake tortoise.

Adaptions

Researchers found that although there is some variation in pancake tortoise habitat, there are some common elements. Most of the inhabited crevices were quite deep, had uncluttered rock floors and were located near a convenient route to the ground, presumably to allow the tortoises easy access to feeding areas. The crevices also usually tapered to a height of nearly 2 inches (5 cm) at some point. Tortoises can wedge themselves into this narrow area for protection. Crevices that fit these criteria are usually found in weathered, but not disintegrating, outcrops. Older kopjes are often too broken up to provide suitable shelter, while unweathered rocky areas do not have deep crevices. The softness of the shell comes from the underlying structure of the bones. Most tortoises’ bones are solid, with very little space between the individual bones under the carapace and plastron. However, in the pancake tortoise these bones have many openings, or fenestrations, in them. Juveniles of other tortoise species possess similar fenestrations in their bones, which fill in as the tortoise grows, leaving the carapace and plastron solid and inflexible. This growth apparently does not occur in Malacochersus tornieri. Unfortunately, cracks and crevices only provide protection if you can reach them. Luckily for the pancake tortoise, less bone means a lighter animal, so they can move more quickly than tortoises with a thick shell. It is quite possible that they are one of the fastest tortoises in the world. When threatened, they will not crouch down and withdraw into their shells. Instead, they will make a dash for the nearest rocky shelter. Pancake tortoises tend not to stray very far from protection, and they also seem to be able to locate their favorite hideaways quickly when displaced. Finally, the pancake tortoise’s flat shell and extreme agility allow it to flip itself over quickly when it lands on its back, a handy ability for a tortoise that spends most of its time climbing around on boulders and rocky hills. In their natural element, individual animals can be very hard to spot. Although they leave their cracks and fissures to bask in the sun and to eat, the brown or horn color of their carapace, combined with a random pattern of radiating lines on each scute, allows pancake tortoises to blend into the background, making them difficult to see. In this regard, their coloration is similar to other smaller tortoises, such as the Padlopers (Homopus species) of South Africa or the more widely distributed hingeback tortoises (Kinixys species). The coloration and patterning of the carapace and plastron is quite variable, and can fade with age. The shapes of the pancake tortoise’s head, legs, feet and other body parts are similar to those of many other tortoises. Males can be identified by their longer and thicker tails relative to the females and by their smaller overall size. Because of the separation of the kopjes, they live in isolated groups. They are excellent climbers, and make their homes under rocks, in rocky crevices (hence the alternative name crevice tortoise), or in small caves. Although they do not appear to hibernate, they may aestivate during the hottest months (January and February).

Special Interests

Pancake tortoises in captivity will eat many of the same things as they will in the wild, and drier grasses and alfalfa should be provided to add bulk and fiber to their diet. Tortoises will also take food such as lettuces, squash, carrot, broccoli, green beans, cabbage, some melons, and occasionally other fruit. Vitamin supplements are not essential if a varied diet is provided. A small amount can be given infrequently. A water bowl can be provided, although they may only use it rarely. The biology of the wild tortoises is still poorly understood, and there is some evidence that their social behavior also sets them apart from most other chelonians in that they may occur in fairly large aggregates.

Folklore

Years ago, before the common name “pancake tortoise” became popular, Malacochersus tornieri was known as the “soft-shell” tortoise because of its pliable shell. Although their pliable plastron allows these tortoises to “inflate” themselves to increase their thickness, earlier claims that they can inflate and wedge themselves in rocky cracks “chuckwalla style” are now believed to be untrue.

Conservation

The major threat to the pancake tortoise is the pet trade. Their curiosity value, combined with their small size, has fueled large-scale collection of these tortoises for the pet trade, and they were once commonly seen for sale in local pet stores, but limited availability and rising prices have made this a rarity. Habitat that is suitable for pancake tortoises is not common or extensive when found, which limits the size of the population in those habitats. Unfortunately, few private individuals have successfully bred pancake tortoises, and captive bred pancake tortoises are rarely available. Tortoises collected by local hunters deal with local middlemen. Animals are occasionally stockpiled in local areas until an order for tortoises arrives from an exporter. These exporters contact the local middlemen, obtain the necessary permits, and ship the animals to wildlife importers in Europe and the United States. Individual collection sites can be responsible for the collection of hundreds of tortoises at a time. Local hunters only receive a few cents per tortoise, with the middlemen making less than 50 cents per animal. Once collected, tortoises face a potentially long wait until exported, and then must survive the stressful exportation process. Recently the Tanzanian government has reduced drastically the number of exported tortoises, and the European Economic Community has banned their import. The number of Pancake tortoises entering the United States has dropped, and prices for Pancake tortoises have risen in the last few years. Perhaps these changes will convince more commercial turtle breeders to begin working with Pancake tortoises.

Jacksonville Zoo History

Exhibit

Seronera Reptile House