Nigrita is a Galapagos tortoise (Chelonoidis nigra) that lives at the Zoo Zürich in Switzerland. At 80 years old, she has becomes a new mother and laid a clutch of eggs that produced nine healthy hatchlings. Nigrita is part of a breeding program to increase the tortoises’ numbers. She was mated to a young male called Jumbo. He’s 54 years old and weighs 440 pounds.
Nigrita first came to the Zoo in 1946 and laid her first clutch of eggs in 1980. Sadly, none of those hatched. She laid her first surviving clutch in 1989 and has produced 91 tortoises over the years, many of which have been sent to other zoos. Nineteen of her progeny remain at the Zoo Zürich, and they range in age from a few days to eight years old.
When the keepers discovered the new batch, they dug them up and put them in an incubator which they watched for over two months. The Zoo Zürich claims to be only institution in Europe to have successfully bred Galapagos tortoises in captivity.
The Galapagos tortoise has one of the longest life spans of any animal on Earth; they can live for over 150 years. An 80-year old tortoise is therefore hardly elderly; in fact, Nigrita is in her prime. Galapagos tortoises reach sexual maturity when they’re around 40 years old.
The tortoises owe their longevity to a slow metabolism and their ability to store lots of water. They can survive for a year without eating or drinking. Galapagos tortoises are herbivores and eat grass, berries, cacti, lichens and leaves. They get most of their water from the plants they eat.
Newly hatched tortoises weigh four or five ounces, while the adults can weigh 400 to 700 pounds. Nigrita weighs a dainty 220 pounds and is therefore still growing herself.
The Galapagos tortoise is an endangered species, and humans may be to blame. People journeying in boats and ships would kill the tortoises for their meat, while some of the animals that traveled with them ate the eggs. The tortoises’ slow growth rate and late sexual maturity make them vulnerable to extinction, as does the fact that the wild populations occur only on the Galapagos Islands. Galapagos tortoises also produce relatively few young; a single clutch will have no more than 16 white eggs that resemble billiard balls.