Chester Zoo has performed a world first by successfully breeding a lizard-like reptile outside its native New Zealand in the battle to conserve an endangered species older than the dinosaurs.
Isolde McGeorge has taken care of tuatara at the zoo since 1977 so to say she has patience is something of an understatement.
But it would appear that getting tuatara to breed in captivity is even more difficult than getting pandas in the mood for romance.
They take 20 years to reach sexual maturity, come into breeding condition once every four years and live a slow-paced existence – fortunately their life expectancy is 120 years.
The rare newcomer arrived weighing 4.21 grams following a 238 day incubation period – the egg from which the youngster hatched was laid on April 11 and hatched on December 5. It could grow to as long as 80cm or 31 inches.
Specialist keeper Isolde must feel like a proud surrogate mother to the tuatara, an ancient reptile that flourished on almost every continent 225 million years ago but is now extinct everywhere except New Zealand.
The sex of the creature has not yet been determined but it is believed to be female and the new arrival has been nicknamed Baby Isolde in honour of her patient keeper.
She said: “Breeding tuatara is an incredible achievement. They are notoriously difficult to breed and it’s probably fair to say that I know that better than most as it has taken me 38 years to get here. It has taken lots of hard work, lots of stressful moments and lots of tweaking of the conditions in which we keep the animals along the way but it has all been very much worth it.
“This animal has been on the planet for over a quarter of a billion years and to be the first zoo to ever breed them outside of their homeland in New Zealand is undoubtedly an amazing event. It’s one of the most momentous events for the reptile team at the zoo since we discovered Komodo dragons are capable of virgin births in 2006.”
The new arrival is the offspring of mother Mustard and father Pixie.
The duo, along with four other females, was accompanied by a Māori chief when they ceremoniously arrived in Chester from Wellington Zoo in 1994.
Isolde added: “When you’ve worked with tuatara for as long as I have you come to realise that they don’t do anything in a hurry. Their metabolism is incredibly slow - they take only five breaths and just six to eight heart beats per minute and they only reproduce every four years with their eggs taking a year to hatch.
“We’ve waited a very, very long time – 12 years with this particular pairing. The night before it hatched I spotted two beads of sweat on the egg. I had a feeling something incredible was about to happen and so I raced in early the next day and there she was.
“Immediately I broke down in tears – I was completely overwhelmed by what we had achieved. Now that we have all of the key factors in place, the challenge is to repeat our success and to do it again and again.”
For reasons unknown, it was around 70 million years ago the species became extinct everywhere except New Zealand, where it now has iconic status. The tuatara is steeped in Māori culture and is highly revered. The islands on which they live are now protected and very few people are given permission to visit.
“Tuatara lived before the dinosaurs, they lived with the dinosaurs and they survived after dinosaurs had died out. They really are a living fossil and an evolutionary wonder,” added Isolde.
“There is no other reptile like it on the planet – the species is very, very different to anything else. They have no external ear openings, they don’t possess normal teeth but instead have projected serrations from their jawbones and they have a ‘third eye’ in the middle of their heads.
“These ‘eyes’ are equipped with a lens, retina, cornea and connective tissue leading to the brain but in fact have no visual function, instead they’re photoreceptors and are believed to utilise UV light.”
Although the tuatara looks very much like a lizard, it actually belongs to a group of animals commonly known as beak heads, or Rhynchocephalia. Chester Zoo, which has seven tuatara including the newcomer, has looked after the species since 1962.
Collections director Mike Jordan commented: “The intensive care given and the intricate skills developed along the way are exactly what you need to hone if you’re to save highly threatened species in the wild. For example, we’re currently working to conserve critically endangered mountain chicken frogs and Bermudan skinks, both on the very brink of extinction and both incredibly difficult to breed.
“In many ways these species are heading towards a last chance saloon but our achievements with the tuatara certainly fill us with confidence that we can breed them and, subsequently, help to save them.”