Mommy: Female, hatched in the wild on the Galapagos Islands. She arrived at the Zoo on April 23, 1932 but it is estimated that she hatched in 1928. She has been at the Zoo longer than any animal in the current collection.
Little Girl: Female, hatched at the Bermuda Aquarium and Zoo. She arrived at the Philadelphia Zoo on May 11, 1956. It is estimated that she hatched in 1940. She is the offspring of tortoises collected from South Albermarle Island during the Townsend expedition of 1928.
3 young Galapagos tortoises, unknown sex, arrived at the Zoo on July 19, 2011 from the Gladys Porter Zoo. All hatched in 2009. Their sire (father) is on breeding loan to Gladys Porter from Philadelphia Zoo. Their names are Peaches, Victor, and JP.
Tortoises have been on Earth a very long time, dating back at least 200 million years, which means they shared the planet with dinosaurs. Galapagos tortoises are the largest living tortoises, and they can live to be over 100 years. They live in warm dry regions and cool forest areas on the sides of the volcano.
Not only are the males generally larger than the females, but they also have relatively longer tails. Galapagos tortoises are typically an overall dull black color, and they have paler, pink skin around the head and throat compared to the Aldabra tortoises.
Longevity
This species can live over 100 years. The oldest known animal lived to be 152.
Reproduction
Near the end of the wet season in the spring, the female Galapagos tortoise will move to arid lowlands with well-defined nesting sites. To soften the ground, the female urinates on a patch of soil in an open, sunny spot. The tortoise then lays 2-20 white, hard-shelled, spherical eggs about the size of billiard balls in the hole. She lowers herself over the opening and, by sliding her underside about, raises mud to form a smooth cap almost flush with the surrounding ground. This cap hardens in the sun. The tortoise's eggs hatch after 4-8 months. Hatchlings need rainfall to soften the mud cap so that they can dig their way out of the sealed chamber.
The sex of Galapagos tortoise babies is determined by the incubation temperature of the eggs. Temperatures of less than 28 degrees Celsius produce males and above 29.5 degrees Celsius produce females.
Behavior
Galapagos tortoises are terrestrial and diurnal, or active in the daytime, and very fond of water. They are slow-moving animals, moving only 0.16 miles per hour. They have a dominance hierarchy based on the height to which the tortoise can stretch its head. The Galapagos tortoise's eyesight is extremely poor, so much so that the males will try to mate with almost anything resembling a female, even a large rock. These tortoises spend their day grazing and relaxing in the sun. They also enjoy drinking and wallowing in puddles of water. Nights are usually spent half submerged in mud or water or burrowed in dense brush. This keeps them warm during the cool night hours.
Adaptations
Galapagos tortoises have large scales on their legs that act as protective devices when they withdraw into their shell. When withdrawing, they protect their head by meeting their elbows front. The Galapagos tortoise's foot bones are structured to facilitate walking, and their pillar-like legs help support their weight. Their lower jaws are covered by horny ridges with serrated edges that help them cut through tough plants. Galapagos tortoises also have a good sense of smell.
Conservation Status
On the 2007 IUCN Red List of Threatened Species, the Galapagos tortoise is listed as Vulnerable.
To learn more about the conservation efforts at the Philadelphia Zoo, click here.