His species are the ultimate survivors, the solitary legacy of an order of reptiles that thrived in the age of the dinosaur. But one tuatara needed a little extra help.
The young adult male almost starved to death after being bullied by other alpha males in their Cape Kidnappers' sanctuary this year.
But after five months' rehabilitation at Massey University's Wildbase Hospital, including a steady supply of "tuatara candy" - mealworms, crickets and huhu grubs - he will next week return to the Hawkes Bay sanctuary. A fence will be moved to keep him away from alpha males and decrease competition for food.
The tuatara was found by Massey University Veterinary Teaching Hospital veterinary resident Rebecca Webster in mid-April, skinny, weak and depressed.
She and a friend took the tuatara to the sanctuary hut, fed him and drove him to Wildbase.
Wildbase wildlife technician Deneka De Sousa said the reptile was severely emaciated. "You could see his spinal cord, pelvic bones and ribcage. He'd been starved for quite a long time."
The tuatara was warmed in an incubator, given fluids under the skin to rehydrate, subjected to ultraviolet light to prevent Vitamin D deficiencies and fed calcium C powder to prevent metabolic bone disease.
Best of all was the grub. Tuatara "candy" and a protein and carbohydrate combination described as "tuatara meatballs" helped him stack on the grams.
His weight, a gaunt 400g on arrival, was now a healthy 560g and he was being fed only once every two days to prevent him becoming overweight, De Sousa said.
"Once he got here he started gobbling up food within seconds, which is a good sign. He's doing so well. He's very active."
After six months it would be hard to say goodbye. "But just thinking of him going back into the wild makes us happy."
For a video of the tuatara, go to bit.ly/1O4o7Ig