Eight rare tortoises have been stolen from the Shoalhaven Zoo, prompting pleas for their safe return.
Zoo owner Nicholas Schilko said robbers had broken the lock of the South African leopard tortoise enclosure and taken the animals on Wednesday night.
The smallest tortoise was about the size of softball, the largest about the size of a basketball, he said.
Mr Schilko said the oldest tortoise had recently laid eggs, which she buried, and he had recovered them and put them into an incubator.
He said the tortoises were herbivores which ate leafy greens.
While they may look quite hardy, if treated roughly or dropped they could receive internal injuries, he said.
"It's questionable the type of people who would steal them, are they the type of people who care enough to give them the right type of treatment, who can be sure," he said.
Mr Schilko encouraged anyone with information about the crime to come forward.
"We've had a monkey stolen, probably four years ago, and we recovered that via anonymous tip off," he said.
Mr Schilko said there were only 50 leopard tortoises in Australia and New Zealand.
Anyone with information about the robbery should contact the police on 131 444 or the zoo on 02 4421 3949.