Tortoise, Red-footed


Chelonoidis carbonaria


Red-foot tortoises have red scales on the limbs, as well as red, yellow, and/or orange facial markings. Length: 10 - 14 inches (25.4 - 35.6 cm) and in rare cases may grow up to 16 inches (40 cm).  There is also a smaller phenotype commonly called the ‘cherryhead’ red-foot, which can be identified by its’ bulbous nose and darker plastron. This phenotype, which does not bear subspecies classification at this time, ranges in size as an adult from 10 -12 inches (25 - 30 cm).  Males are longer and heavier than females, but not wider or taller. Weight: males about 20 lbs. (9kg) or more, while females weigh a bit less.  As with other tortoise species, males have a concave plastron.  As young mature, both sexes develop a unique mid-body constriction (some have referred to it as a “waist”) that, from a top view, gives the tortoises a decidedly hourglass appearance. This “hourglass” figure is much more developed in males than in females.  Mature males also have longer and wider tails than females.

Family

Testudinidae

Order

Testudines

Class

Reptilia

Range

Panama, Colombia, Venezuela, Guyana, Surinam, French Guyana, Brazil, Bolivia, Paraguay, and Argentina; also found on Trinidad, and have been introduced to many islands in the West Indies.

Habitat

It occurs in all types of forest habitat (rainforest, temperate forest, and dry thorn forest), and also is found in savanna areas, including man-made grasslands resulting from ranching and slash-and-burn agricultural practices.

Life Expectancy

40 – 50 years

Sexual Maturity

8 – 12 years

Diet

In the wild, they eat fallen fruits such as wild plum, mushrooms, vines, grasses, succulents, snails, ants, termites, bees, beetles, butterflies and carrion (agouti, peccary, bird, snake, lizard, and deer carcasses), and is attracted to yellow and red flowers; in the Zoo they are fed a mixture of greens, vegetables and fruits, occasionally supplemented with flowers.

Status

CITES – Appendix II

Behaviors

The bulk of the red-footed tortoise’s diet is fruits, comprising up to 70% of the total intake during the wet season and approximately 40% during the dry season. Fruits are normally consumed in a very ripe state after they have fallen from the tree. After fruits, flowers are the second most popular food of the red-footed tortoise. During the dry season, flowers constitute up to about 25% of the diet while the rest of the diet (about 20%) is comprised of green leaves and stems with a further 20% made up of miscellaneous fungi, mosses, termites and carrion. Males fight one another for access to females during the breeding season. Male to male combat begins with a round of head bobbing and then proceeds to a wrestling match during which males attempt to turn one another over. The successful male (usually the largest male) then attempts to mate with the females present. The ritualistic head movements displayed by males are thought to be a method of species recognition. Other tortoise species, most notably the closely related and sometimes sympatric yellow-footed tortoise (Geochelone denticulate), have different head movements. Red-foot tortoises head movements are a series of lateral jerks; by contrast, yellow-footed tortoises utilize a long sideways sweep in their displays. Females lay eggs between July and September. Clutch sizes vary from 2 to 8 eggs, with clutches of 3 to 5 eggs most common. Larger eggs and clutches are generally produced by larger and older females. They are generally buried in a nest in the ground. However, Pritchard reports that locals in Panama have observed eggs laid in leaf-litter on the forest floor. Eggs are oblong (about 2” x 1.5”) and have brittle shells. After egg-laying is complete, the female shovels soil over the nest with her hind legs. Nest excavation, egg laying and covering the nest may take as long as 3 to 4 hours. The incubation period is generally 105 to 202 days (mean 150) but may be as long as one year. Once hatching commences, it may take 2 days or more to complete, interspersed with frequent rest periods by the hatchlings. After hatching, shell fragments may adhere to the hatchlings’ carapace but will eventually fall off. Hatchlings are 1 to 1-1/2 inches long. Although they may appear somewhat misshapen upon emergence from the shell, the carapace will straighten within the first few days. They do not have any of the tooth-like projections on the edges of the carapace, like those found in the yellow-footed tortoises. A pinkish or yellowish sack attached to the hatchling’s plastron contains all the nutrients it requires for the first week. During mating males make a clucking sound that sounds amazingly like a hen.

Adaptions

The unique body shape of the male red-footed tortoise (concave plastron) facilitates the mating process by allowing him to accommodate the shell of the female and maintain his balance during copulation.

Special Interests

The species name for this tortoise, carbonaria, refers to the carbon-like color of its dark brown or black carapace. The red-footed tortoise is known in Brazil as Jabuti and in Venezuela as Morrocoy. Interestingly enough, tortoises are considered “fish” by the Catholic Church and during holy week, red-foots are consumed in huge numbers. Red-foots are collected and shipped to many different South American cities to be sold as a delicacy. The role of red-footed tortoises (Geochelone carbonaria) and yellow-footed tortoises (G. denticulate) as seed dispersal agents was investigated in northwestern Brazil from 5 to 26 January 2002 by analyzing fecal samples for frequency and viability of seed species and estimating daily displacement of tortoises from recaptured and thread-trailed individuals. Fourteen of 19 fecal samples contained a total of 646 seeds represented by 11 plant species. The most abundant species was Ficus sp. (N= 400) with 100 percent of seeds viable, followed by Aechmea sp. (N = 88) with 93 percent of seeds viable, and Genipa Americana (N= 59) with 91 percent of seeds viable. Mean minimum retention time of seeds was 1.6 days and mean daily displacement of tortoises based on recaptured (N= 7) and thread-trailed tortoises (N= 2) was 187 ft (57 m). Thus, the diversity and proportion of viable seeds consumed by tortoises, combined with the seed retention times and daily movements, suggest they may be effective dispersal agents. These preliminary findings warrant further investigation into the ecological role of these tortoises in Neotropical ecosystems and their contribution to the maintenance of species diversity and forest structure. The most common problem related to tortoise shell health is called “pyramiding”. Pyramiding is a form of metabolic bone disease (MBD). It is characterized by a buildup or stacking of keratin in the scutes. There are many factors that contribute to pyramiding, and much disagreement about the primary cause between herpetologists, veterinarians, and breeders. Traditionally, the focus has been on protein, because protein in the diet causes the shell to put down heavy layers of keratin, resulting in conical scutes on the shell. Lack of calcium may also result in the soft shells that often accompany pyramiding. More recently, research suggests that humidity is key to carapace health in red-foots and other species. Another less common shell health issue is known as “shell rot.” Shell-rot is a generic term which describes the visible effects of bacterial, fungal or even algal (in aquatic species) diseases of a tortoise’s or turtle’s shell. Some common causes of shell rot include improper enclosure humidity, poor hygiene, ticks, and aggression by other tortoises. Deep-seated shell abscesses are particularly serious, and invariably require surgical draining and removal, followed by selective treatment with systemic anti-microbials. If detected early enough, the fungus may be treated with a cleansing, at least twice daily, with a povidone-iodine or chlorhexidine solution.

Folklore

Conservation

In every country in its range, the biggest threat to the survival of red-footed tortoises is overhunting. Because they can tolerate long periods of time without food and water, an otherwise evolutionary advantage, makes this species both easy and profitable to transport. Another threat facing red-footed tortoise populations is habitat loss and disturbance. Although it has been observed that red-footed tortoises can live on land that has been converted to agriculture, their densities are much lower than they are in natural, unaltered habitat. Tortoises living on agricultural lands are much easier to locate, so higher hunting rates may account for this difference. Exportation for the pet trade also has a negative effect on red-footed tortoises, although it is much less of a threat to their survival than either hunting or habitat loss. Their natural history provides insight into two areas, the susceptibility of this species to overhunting and habitat loss, and captive husbandry and reproduction. Conservation efforts include the establishment and protection of wildlife reserves and national parks, where red-footed tortoises and other animals are protected from hunting.

Jacksonville Zoo History

The red-footed tortoise has been at the Jacksonville Zoo off-and-on since 1978, and has bred here.

Exhibit