Radiated Tortoise

(Astrochelys radiata)

Habitat and Distribution: Found in woodlands, thorn forests, and scrubby grasslands of the island of Madagascar.

Size: 12-16 inches long; up to 35 pounds. Males are slightly larger than females.

Wild Diet: Grasses, succulent plants, flowers, leaves, vegetables, fruits, berries, and carrion

Predators: Snakes and birds of prey

Reproduction: Males start mating when they are about a foot long, and females when they are a few inches longer. Females usually lay their eggs in nests about 6-8 inches deep, deposit 3-12 brittle-shelled eggs, then cover the nest and move away. Eggs incubate for 5-8 months. Newly hatched radiated tortoises are 1-2 inches long and their carapaces are brightly colored and somewhat flattened compared to an adult.

Behavior: Like all tortoises, the radiated tortoise lacks teeth and relies on the sharp cutting edges of its jaws to tear food into small pieces. They also use their forefeet to hold down plants so that the shoots can be nibbled more easily. Tortoises can survive for long periods of time without drinking; they obtain water from their food or produce it metabolically.


IUCN Status: Critically Endangered

Radiated tortoises are at risk of going extinct in the wild because humans regularly capture them for the pet trade, hunt them for food, and degrade their habitat. In 1985, a Species Survival Plan (SSP) was established for radiated tortoises. SSPs monitor zoo-based breeding of endangered species to ensure maximum growth and diversity of captive stocks. After a tortoise’s genes are well represented in the zoo population, he or she is no longer permitted to breed. Through careful record keeping and management, SSPs maintain the genetic variability and overall health of zoo-based populations and may save species like the radiated tortoise.

Did you know?

  • This tortoise is named for the brilliant yellow stripes radiating from the center of each dark plate on its shell.
  • When attacked by a predator, the radiated tortoise pulls its head into its shell and emits a high-pitched cry.
  • The strength and rigidity of the shell results from an inner bony casing of fused plates (called scutes) that are covered with keratin shields.