Red-footed tortoises (Chelonoidis carbonaria) are tortoises from northern South America. They are medium-sized tortoises that generally average 30 centimetres (12 in) as adults, but can reach over 40 cm (16 in). They have a dark-colored loaf-shaped carapace (back shell) with a lighter patch in the middle of each scute (scales on the shell), and dark limbs with brightly colored scales that range from pale yellow to dark red. There are recognized differences between red-footed tortoises from different regions. They are 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.
Their natural habitat ranges from savannah to forest-edges around the Amazon Basin. They are omnivorous with a diet based on a wide assortment of plants- mostly fruit when available, but also including grasses, flowers, fungi, carrion, and invertebrates. They do not brumate but may aestivate in hot, dry weather.
Red-footed tortoises show gender, regional and individual variations in color, shell shape, and minor anatomic characteristics. Adult red-footed tortoise carapaces are generally an elongated oval with sides that are nearly parallel, although the sides of males may curve inwards. They are fairly highly domed and smooth with a rather flat back. There is often a high point over the hips and a small sloped section over the neck. The vertebral and costal scutes (the scutes along the center and sides of the carapace) are black or dark brown with a pale yellow areole in the center. The marginals (scutes along the edge of the carapace) 'tuck under' along the sides and flare slightly over the limbs. They are dark with the pale aureole along the middle of the lower edge. The nuchal scute (the marginal over the neck) is absent, and the marginals over the tail are joined as one large supracaudal. Growth rings are clearly evident in most individuals but become worn smooth with age.
Plastron view of an adult male red-footed tortoise showing pale coloration and central darker markings, male tail and anal scutes, and plastron indentation
Plastron view of an adult male red-footed tortoise
The plastron (bottom shell) is large and thick along the edges. The gulars (frontmost pair of plastron scutes) do not protrude much past the front of the carapace. The plastron of a male is deeply indented, and the anal scutes (rearmost pair of plastron scutes) may be used to sex the animal while the color pattern varies by region.
The head is relatively small with a squared-off profile and flat on top, longer than it is wide. The eye is large with a black iris, and rarely any sclera visible around it. The upper jaw is slightly hooked, and the upper jaw is notched in the front middle. There are fifteen to twenty 'teeth' or fine grooves on each side of each jaw. A nearly circular tympanum is located behind and below the eye and is covered with a dark scale. The scales of the head are generally smallish and irregular, becoming small and pebbly on the neck. Many of the scales are colored pale yellow to brick red, especially those on the top of the head, above the tympanum, around the nostrils, on the lower jaw, and on the sides of the neck. Males are usually slightly more colorful than females, and colors vary by region.
The limbs are generally cylindrical with four claws on the forelimbs and five on the hind, but no visible toes. The forelimbs are slightly flattened and the front surface is covered with large scales, mostly with the same color as the head. They are not as large or protrusive as they are in more primitive species such as the African spurred tortoise (Geochelone sulcata). The tail is muscular, varies in length and overall shape by gender, and lacks any sort of claw on the tip.
Average adult sizes vary by region and gender, and 'giants' are often encountered. Red-footed tortoises average 30–35 cm (12–14 in) with males slightly larger overall. Red-foots of up to 45 cm (18 in) are fairly common and over 50 cm (20 in) are occasionally discovered. The largest known specimen was from Paraguay, was 60 cm (24 in) long, and weighed over 28 kg (62 lb)! It is unknown if the 'giants' represent diet availability, genetic issues, longevity, or other possibilities.
Hatchling and young red-footed tortoises have much rounder and flatter carapaces that start off as mostly pale yellow to brown. New growth adds dark rings around the pale center to each scute. The marginals of very young red-footed tortoise are serrated, especially over the hind limbs. This probably aids in both camouflage against the leaf litter and in making the small animals harder to eat. Young tortoises are generally more colorful overall.
Redfoot tortoises that live outdoors are tolerant to various temperature ranges. High temperatures are generally not going to be a problem provided that the tortoise has a shaded area to escape to if desired and constant access to water to soak in and drink.
We keep our adult red-footed tortoises outdoors in Las Vegas with temperatures of up to 115 degrees Fahrenheit occasionally and have had no losses to heat. Keep in mind the fact that our red-footed tortoise “jungle” is sprayed with sprinklers several times a day, which lowers the overall temperature in that area and raises humidity. The entire area is covered with 80 percent shade cloth.
The tortoises themselves can also handle surprisingly cold temperatures, as low as 45 degrees, with no problems. When nighttime temperatures drop below 50 degrees, a heated hide box should be provided that maintains at least 60 degrees at night (in the 70s is better), or the tortoises should be brought in during those times. Red-footed tortoises are kept outdoors year round in some parts of the country where nighttime lows in the winter are 20 degrees (including here in Las Vegas). It is absolutely required that these tortoises are checked on each evening to make sure they get into a heated area and do not fall asleep out in the open and become exposed to cold temperatures at night.
Indoors, redfoot tortoises can be maintained at normal room temperatures: 68 to 80 degrees. They should also have a basking area heated by an overhead light or a ceramic heat emitter. This warm spot should be in the 90-degree range. While some don’t think it’s needed, we provide a UVB light in the indoor enclosures to help them properly process the calcium in their diets. When placed overhead, it will not lead to eye damage as is sometimes claimed. Lights should run 12 to 14 hours a day, and a mild heat source can be used 24/7 under or over the hide box area (small heat pads, red bulbs or ceramic heat emitters work great for this). Lamp timers make the light cycle consistent and easy.
Redfoot tortoises exist in a wide variety of habitats in the wild, from grassland to jungle, almost all with moderate to high humidity and moderate temperatures. Red-foots can handle variable amounts of humidity in captivity once grown, but babies should be kept humid to ensure proper smooth shell growth in their first few years.
Redfoot tortoises do not hibernate but will go through a winter slow-down period during cooler weather and shortened day-lengths. As adults, red-footed tortoises can safely handle body temperatures as low as 45 degrees at night as long as they are able to heat up into the 70s during the day. Summer temperatures up to 100 degrees can be tolerated as long as there is a cooler, shaded retreat the tortoise can get into. Moisture is not a problem in warmer temperatures (a cool mudhole on a hot day), but the tortoises should be kept dry on cold nights.