Wednesday, October 1, 2014

My Cousin: The Hinge-Back Tortoise

The Hinge-back Tortoises, as they are commonly called, develop a hinge that allows them to close the rear of their carapace, protecting their back legs.
Hinge-back tortoises appear to be typical tortoises on first inspection but Hinge-backs are considerably longer than they are wide, more closely resembling a Red-footed Tortoise than a Leopard Tortoise, for example. In overall size this species are on the smaller end of the tortoise range.
Hinge-backs possess the elephantine feet associated with tortoises, although the front feet are not quite as blunt as the rear. Their forelegs usually have a series of enlarged, downward-pointing scales while the rear legs lack these scales. In these chelonians the head is only of medium size, while their tail ends in a nail-like spike. Of course, the Hinge-back's distinguishing characteristic is the unique hinge that develops in adults at the rear of the carapace, between the seventh and eighth marginal scutes.

Hinge-Back Tortoise enjoying a salad!
The carapacial hinges allow the tortoises to clamp down the rear of their carapaces, giving increased protection to their tail and legs. Hinge-backs also have effective defenses for their front legs and head. When threatened, a tortoise can retract its head quite far. Its front legs then seal the anterior opening in the carapace; the knees meet in front of the head with the feet pointing to either side. The enlarged scales on the forelegs face outward in this position, protecting the legs themselves and effectively closing the tortoise off from the world.
The Hinge-backs inhabit a diverse array of habitats in central and southern Africa, primarily in grassland and savannah regions, although some individuals can be found in coastal forests. These regions often go through times of drought, and Bell's Hinge-back burrow underground to survive these periods. This tortoise has large anal sacs which can be filled with water, taking up a large percentage of the abdominal cavity, to help it during the dry season. This stored water may be used by females when building nests to help loosen and moisten the soil in and around the nest.
Hinge-backs are omnivorous feeders in the wild. In addition to greens, they consume snails, insects such as millipedes and beetles, and will scavenge corpses when encountered. In captivity they will eat a wide variety of vegetable matter, including green beans, broccoli, squash, mushrooms, and bananas. They readily take mealworms and mealworm beetles, cooked chicken, and liver. Earthworms are relished; they are grabbed, whipped from side to side, and swallowed rapidly.

1 comment:

  1. I love this action-still photo at the top with the infinite horizon meeting tabletop.