Red-footed tortoise

Species of tortoise

Speciesbox
| name = Red footed tortoise
| image = Geochelone carbonaria IMG 4978. jpg
| genus = Chelonoidis
| species = carbonarius
| authority = (Spix, 1824)
| synonyms = * Testudo carbonaria Spix, 1824:22
Testudo hercules truncata Gray, 1830:3
Testudo boiei Wagler, 1833:pl.13
| synonyms ref = In Portuguese, jabuti (jaboti) refers to both the red footed tortoise and the yellow footed tortoise. It is also called kati in Natú and sambó in Kiriri.

Red footed tortoises were originally assigned to the genus Testudo (named 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—the tortoises. In 1835, Leopold Fitzinger used Geochelone to differentiate some non Mediterranean tortoises, apparently based on size and lack of specific identifying characteristics such as the hinged shell in the African hingeback tortoises. He used the term Chelonoidis as a subgenus for the species from South America. Few people used these terms until they were resurrected by Hewitt in 1933 and Loveridge and Williams in 1957. 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, no specific definition of Geochelone is given, and Chelonoidis is primarily used for geography rather than unique anatomic characteristics. 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. 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 shell, head, and limb coloration. The variants south of the Amazon are generally both larger and smaller than the holotype, have a very different plastral pattern, and have an enlarged scale or 'spur' on the inside of the fore limb elbow.

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. Size tends to be larger on average then northeastern variants, with the largest individuals found in this area. Fore limbs 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. They are seen in the Gran Chaco Bolivia, Paraguay, and northern Argentina.

Carapaces of the eastern variants are often light grey or whitish between the scutes. Their plastrons are mostly dark in a symmetrical mottled pattern. Size tends to be smaller on average than northeastern variants, also reaching sexual maturity at a smaller size. Fore limbs 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. They are located in east to southeast Brazil. The red headed type of this variant is often called a 'cherry head' in the pet trade.

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. Most species of tortoise spend much of their day inactive, and red footed tortoises generally spend over 50% of the daylight hours at rest. They may rest for even longer after a large meal, with five to ten day stretches being common. One large specimen seems to have stayed in the same position for over a month. Resting tortoises barely move, allowing leaf litter to accumulate on them, and termites have built tunnels on the carapaces of resting red footed tortoises. They seek shelter in places that offer thermoregulation and protection from predators. Treefalls are a favored site, as are debris piles, burrows (especially those of the armadillo (Dasypodidae family) and agouti (Dasyprocta species)), hollow logs, holes, and heavy vegetation cover. They generally try to find tight fitting resting places, and will occasionally 'wedge' themselves between roots and trunks but remain otherwise exposed. Burrows and holes are often flooded and the tortoises will rest in the water and mud with just their nostrils and eyes exposed. In warmer weather, they press up against moister, cooler surfaces in shelter areas. The tortoises show personal preferences with many individuals always seeking out a specific type of shelter. Besides communal shelters and scent marking, red footed tortoises also show other signs of semisocial behavior such as lack of aggression at feeding sites, not protecting territory, and group feeding at fruit falls and carrion (although it is not unusual for one tortoise to block access or even try to make off with some of the food). Red footed tortoises often follow each other, usually a smaller one following a larger and quite often males following males, but all combinations are seen. They have also been observed following apparent scent trails laid by an individual a day or two earlier. and because studying fecal pellets gives very different results than what the animals are observed eating. Red footed tortoises have been observed at the base of fruit trees, apparently waiting for fruit to fall. Omnivorous tortoises seek out foods high in calcium even if other foods are more readily available, and even eat mineral rich soil if they cannot get adequate calcium in the diet. The peak time for courtship and reproduction is the early wet season in April and May, although it can happen at any time. Courtship noises and possibly scent cues seem to attract other tortoises to 'courting sites' under fruiting trees such as Genipa.

Heat, light, and humidity must be kept within proper guidelines for healthy tortoises. Red footed tortoises are most active at temperatures from A warmer area of is recommended, and night temperatures can drop a few degrees lower. High levels of humidity should be available in some part of the habitat.