Animal Information

The Red-foot Tortoise (Chelonoidis carbonarius) History, Identification, and Other Info.

All turtles and tortoises were originally assigned to the genus Testudo by Carl Linnaeus in 1758 for a short time, but it soon became the term for turtles with high-domed shells, elephantine legs, and completely terrestrial habits.

Red-footed tortoises are commonly known as red-leg, red-legged, or red-foot tortoise, the savanna tortoise, as well as local names, such as carumbe or karumbe, which means ‘slow moving’ in Brazil and Paraguay.

Other names these reptiles are known to be are Wayapopi or morrocoy, used in Venezuela and Colombia.

There are variations of jabuti such as japuta and jabuti-piranga used in Brazil and Argentina. interestingly, Plinia cauliflora, the Brazilian grapetree, jaboticaba or jabuticaba, derived from the Tupi word jaboti/jabuti (tortoise) + caba (place), meaning the place where you find tortoises.

Red-foot Tortoise Identification

The red-footed tortoise (Chelonoidis carbonarius) “Keel-on-OY-dis Kar-bo-ˈna-ri-us” is a species of medium-sized tortoises. Average adult sizes vary by region and sex, and ‘giants’ are often encountered. Red-footed tortoises average 12–14 in with males slightly larger overall.

The largest known specimen, from Paraguay, was 24 inches long and weighed over 62 lbs. It is unknown if the ‘giants’ represent diet availability, genetic issues, longevity, or other possibilities.

Recognized differences are seen between red-footed tortoises from different regions.

Recognized differences are seen between red-footed tortoises from different regions. In 1982, Roger Bour and Charles Crumly each separated Geochelone into different genera based on anatomic differences, especially in the skulls.

That resulted in the formation or restoration of several genera: Aldabrachelys, Astrochelys, Cylindraspis, Indotestudo, Manouria, and Chelonoidis. Chelonoidis was distinguished from other Geochelone by their South American location, as well as the absence of the nuchal scute (the marginal centered over the neck) and the presence of a large, undivided supracaudal (the scute or scutes directly over the tail), as well as differences in the skull.

Many of these generic names are still debated. For example, there is no specific definition of Geochelone is given, and Chelonoidis is primarily used for geography rather than unique anatomic characteristics.

Various authors have divided the red-footed tortoise into different groups by anatomy and geography. Peter Pritchard recognized seven types, but DNA research has identified five genotypes.

The most obvious differences are between the groups found north or south of the Amazon basin. The ‘northern’ variants all look very much like the holotype and are distinguished primarily by a shell, head, and limb coloration. The variants south of the Amazon are generally both larger and smaller than the holotype, have a very different pastoral pattern, and have an enlarged scale or ‘spur’ on the inside of the forelimb elbow.

Northeastern variant
This is the holotype of the species. Head and limb colors are generally light orange to red. Plastrons are mostly pale yellow. These range in the Guiana Shield- Venezuela, Guyana, Suriname, Guiana, and northern Brazil.

Northwestern variant
They are similar to the northeastern variant, but their carapace base color is grey, dark brown, or coffee rather than black. Their pale plastrons have central dark areas resembling an exclamation point. Their heads and limbs are generally pale yellow to orange. The average size is slightly smaller than usual- 30–35 cm. These are found in southeast Panama and Colombia.

Northern variant
These also are similar to the northeastern variant, with head and limb colors generally pale yellow to light orange. They are rarely read on the heads and limbs are often slightly different colors. The average size is slightly smaller than usual- 30–35 cm. These are found in Colombia, Ecuador, and Peru.

Southern variant
The southern variants’ carapaces are often not quite black to dark brown, sometimes with light grey or whitish between the scutes. Their plastrons are mostly dark in a symmetrical mottled pattern. The size tends to be larger on average then northeastern variants, with the largest individuals found in this area. Forelimbs feature a slightly enlarged scale on the side of the ‘elbow’. Adult males do not have the constricted waist, and females average a bit larger than the males. These are seen in the Gran Chaco – Bolivia, Paraguay, and northern Argentina.

Eastern variant
Carapaces of the eastern variants are often light grey or whitish between the scutes. Their plastrons are mostly dark in a symmetrical mottled pattern. The size tends to be smaller on average than northeastern variants, also reaching sexual maturity at a smaller size. The forelimbs feature a slightly enlarged scale on the side of the ‘elbow’. Their heads and limbs are either yellowish or red, ranging to brilliant cherry-red. These are located in the east to southeast Brazil. The red-headed type of this variant is often called a ‘cherry-head’ in the pet trade

Sexing Red-foot Tortoises

Males are slightly larger and more colorful overall. The carapace of a male from north of the Amazon basin shows a ‘wasp waist’, or constrictions along the sides. The male’s plastron is deeply indented to help with positioning during mating. The male’s tail is long and muscular, generally carried along aside while the female’s tail is short and conical.

The anal scutes vary to allow the male’s tail more mobility and allow more protection for the female’s hind end. The gap between the points of the anal scales and the marginals is wider and the anal scutes form a broader angle- almost a straight line across- in males to allow the tail to move laterally. The angle is more closed (to about a 90° angle) and the points are closer to the marginals in females

History Of The Red-foot Tortoise

Red-footed tortoises range from southeastern Panama to Venezuela, Guyana, Suriname, and Guiana in the north. They are also found south along the Andes to the west in Colombia, Ecuador, Peru, and Bolivia; east to Brazil, and along with the southern range in Bolivia, Paraguay, and possibly northern Argentina.

They are not evenly distributed within their range. For example, they are not often found in central Brazil or in heavily forested areas in general. They have only been documented in Peru since 1985. Accurate range information is complicated by the sheer size of the range, political and geographic barriers, and confusion about where many specimens were collected.

This member of the family Testudinidae is also found on several Caribbean Islands, although it is not always clear if they are native or brought by humans.

Many of the colonies are thought to have been established in the 17th century as food supplies or as pets.

They are found in the Netherlands Antilles, Trinidad, Tobago, Grenada, Barbados, St. Vincent, the Grenadines, Santa Lucia, Martinique, Dominica, Guadalupe, the Leeward Islands, the Virgin Islands, and Puerto Rico.

The genus Chelonoidis has two main subcategories based on appearance and habitat- the C. carbonarius and the C. chilensis groups. The C. carbonarius group has the closely related red- and yellow-footed tortoises that clearly share a common ancestor. The C. chilensis group features the Chaco tortoise (C. chilensis) and Galápagos tortoise (C. niger), which share similar habitats and a basic appearance, but otherwise do not seem to be closely related. The relationship between the groups is unclear.

Several theories are offered to explain the relatively small number of tortoise species in South America and the relationship between them, but the fossil record is not very complete.

One long-held theory is that they came from Asia using the land bridge, then spread down through North America and shared ancestors with the gopher tortoises (Gopherus species).

Another holds Geochelone ancestors floated over from central Africa, taking advantage of their ability to float, resist saltwater, and go without food for extended periods.

DNA studies suggest that the carbonarius group may be related to the African Hingeback tortoises (Kinixys species). This suggests that they might have come from Gondwana before it separated into Africa and South America some 130 million years ago.

One ancestral form from about 5mya, Chelonoidis hesterna is thought to have lived in wet forests and split into two species in the Miocene with the yellow-footed tortoises remaining in the deep forest and the red-footed colonizing the edges of the forests and the emerging savannahs.

As the climate and topography changed, groups of red-footed tortoises became physically separated and genetically isolated.

The species name carbonarius means ‘coal-like’ referring to a dark coal with glowing patches. It was originally identified by Johann Baptist von Spix in 1824.

The holotype was kept in the Zoologischen Sammlung des Bayerischen Staates in Munich, Germany, but was lost. Paulo Vanzolini believes it may have come from near the city of Manaus, Brazil, on the Rio Negro. No subspecies of red-footed tortoise are recognized, although many believe the species has five or more variants that may be subspecies or even separate species.

They are however closely related to the yellow-footed tortoise (C. denticulata) from the Amazon Basin. They are popularly kept as pets, and over-collection has caused them to be vulnerable to extinction.

Husbandry Of The Red-foot Tortoise

The happiest and healthiest red-foot tortoises are kept in naturalistic settings that mimic the native environment to which they come from.

The preferred habitat of the red-footed tortoise varies somewhat by region, but generally includes fairly consistent seasonal temperatures near 86 °F that rarely get lower than 68 °F or over 95 °F, generally with high humidity and plenty of rainfall, although some of the areas can get quite dry.

Most of the range experiences cooler wet seasons from April to August and warmer dry seasons from September to March. Only some parts of the southern range have occasional cold snaps.

Red-footed tortoises are often found in or near transitional areas between forest and savannah, such as forest clearings, wood edges, or along waterways.

Red-foot Tortoise Diet

Red-footed tortoises are primarily herbivorous but will also eat small amounts of animal matter making them omnivorous with a diet based on a wide assortment of plants, grasses, flowers, fungi, carrion, fruit, and invertebrates.

Red-foot Eggs and Babies

Conservation Of The Red-foot Tortoise

Eggs, hatchlings, and young tortoises are food for many predators, but the main threats for adults are jaguars and humans. Population density ranges from locally common to very scarce due in part to habitat destruction and over-collection for food and the pet trade.

The IUCN does not consider the red-footed tortoise to be at risk of extinction. The species is listed under Appendix II of CITES.

Many island populations are likely in serious decline as habitat loss and over-hunting pose a serious threat throughout its geographic range. Without current population estimates, it is difficult to predict the potential conservation and management needs for this species.

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