Red-footed tortoise. Drawing by Margaret Hawley
Found in tropical South America – the Guianas, Venezuela, Brazil, Ecuador and Paraguayand on some Caribbean islands – the red-footed tortoise (Geochelone carbonaria) has a dark carapace with lighter patches of yellow in the centers of the scutes and around the outside edges of the shell. Although there is much variation, the legs and head are often colored with patches of red, orange or yellow. Many individuals have a distinctive constriction in the sides of their shells, giving the appearance of a waistline or an hourglass shape when viewed from above.
Adult males, at an average of 13.25 inches (30.4 cm) long, are somewhat larger than the females, which average 11.25 inches (28.9 cm) in length. They are sexually mature at a smaller size than this, and tortoises owned by one of us (D.S.) have successfully bred at about 8" in length. Males have a concave plastron, just as our own desert tortoises do, and have lower, flatter, and a more pronounced hourglass shape to their carapaces than do females. Males also have longer, thicker tails than the females do. Pritchard reports that the largest red-footed tortoise on record is 17.75" long. Its shell is in the American Museum of Natural History. Although no sub-species have been described red-foots occur over a huge geographic area and there is considerable variation in size and color. Recently, importers and animal dealers have been offering so called "dwarf" red-footed tortoises for sale. These are brightly patterned with scarlet markings, reach a length of 6" to 8" or so, but are otherwise indistinguishable.
The handsome red-foot shares some of its range in the wild with the yellow-footed tortoise (Geochelone denticulata). While both species are found in tropical forests, in Surinam, where there is forest and open grasslands (created by man as a result of "slash and burn" agricultural methods), Pritchard mentions that only the red-footed tortoises appear to have ventured out of the forest into the grasslands. The yellow-footed tortoises have stayed exclusively in the forest. David keeps both species at his home here in southern California. He feels that the red-foots are noisier and hardier, but less aggressive than the larger yellow-foots.
Reproduction & Breeding Behavior
According to both Pritchard and to Ernst & Barbour the mating ritual of red-footed tortoises involves some very distinctive head movements on the part of the male. He begins by standing side-by-side with another tortoise and moving his head suddenly to one side, then returning it to the middle, in a series of sideways jerking motions. (Not like the front facing, head bobbing desert tortoise that many of us are familiar with.) If the second tortoise is a male, he will respond with similar head movements, and some characteristic pushing and shoving may then ensue. If, however, the second tortoise is a female, she will not move her head in response. The male will move around to sniff at her tail, to confirm what he already suspects, before mating begins. Experiments have shown that in order for mating to proceed, not only do the movements of the head have to be precise, but also the coloration of the head has to be correct. An artificial head not colored to match the species' pattern, did not elicit the appropriate response from either male or female.
