Two critically-endangered tortoises the size of golf balls have hatched at Chester Zoo.

The infants, born to mum Smoothsides, 50, and dad Burt, who is 75, are the first of their kind to be bred at the zoo for seven years.

The radiated tortoises are being cared for in a climate-controlled breeding facility. They will eventually grow up to half a metre long and could live to be 100.

Once old enough, they will join four male and six female adult tortoises, from 10 to 74 years old, in the zoo's tropical realm habitat.

Staff have been trying to breed the tortoises since seeing for themselves how their habitat in the forests of southern and southwestern Madagascar has been devastated.


Like most species native to the island, located off the southeast coast of Africa, radiated tortoises are in sharp decline and considered critically endangered.

Image: The species is considered one of the most beautiful tortoises. Pic: Chester Zoo

An estimated 18 million of them have been lost from the island in the last 30 years due to deforestation.

Species such as rats and pigs, introduced by humans, have further hit numbers by eating tortoises' eggs and their offspring.

As many as 45,000 radiated tortoises are harvested from the wild annually for a mixture of things from bush meat, to the pet trade, and even harvesting for craft materials, the zoo said.

They are considered one of the most beautiful types of tortoise and the hatchlings already sport the breed's distinctive star-shaped yellow and black markings on their shells.

Ben Baker, the zoo's team manager of herpetology, said radiated tortoises are faced with a "very real threat of extinction" in Madagascar.

"They naturally have very slow rates of growth and reproduction, which means they have little or no hope of recovering unaided from the many threats that have been forced on them by humans - deforestation, hunting, poaching and predation of eggs from introduced species.

"This is a species that was once seen everywhere in southern Madagascar. However, an estimated 18 million radiated tortoises have been lost in the last 30 years - a staggeringly high number."