Dr Reardon has led the Department of Conservation's grand and Otago skink recovery programme at Macraes Flat for the past four years and was an integral part of the team whose work led to a dramatic recovery in numbers of the critically endangered skinks.
It is this experience he plans to take to his new role as a conservation biologist with the Zoological Society of London's Edge programme, which aims to protect the world's most evolutionary valuable species.
He recently returned from the Sixth World Congress in Herpetology, in Brazil, where he spent a lot of time in meetings with government agencies and non-governmental organisations (NGOs) interested in finding out how his team had achieved success with the skinks.
"It really gave me perspective [that I realised] I'd lost in the last five years, tucked between the tussocks. New Zealand really is a global leader in conservation."
The issue was now on the international agenda as countries acknowledged global extinction was happening as pressures came on from climate change, development and pollution.
"New Zealand is more than ever relevant on the conservation scene."
He considered himself very lucky to be part of an organisation that was aware New Zealand was still in "extinction crisis" and set out of prevent further losses to biodiversity.
"It is a big concern globally there is a lack of understanding of the true costs of conservation."
In his new job, which was based in London's Regent Park, he would take the lessons learnt with the skinks to South Asia, especially India and Sri Lanka, where society was impinging hugely on the biodiversity and ecosystems to the point only small postage stamp-sizes of some ecosystems were left, Dr Reardon said.
The Welsh-born scientist worked as a natural history cameraman before becoming disenchanted, and deciding to move to New Zealand because it excelled in developing conservation management.
"I decided to return to applying scientific logic to achieving good conservation outcomes," Dr Reardon said.
He chose Dunedin because it was New Zealand's wildlife centre and had an excellent university zoology department.
A keen herpetologist (the study of amphibians and reptiles) since he was 6, he was fascinated by Doc's plans for the skinks, which were clearly going extinct.
Initially involved as a Landcare Research scientist looking at whether parasites or disease were the skinks' problem, in 1994 he got "sucked" into managing the Doc programme.
"I saw it as a great challenge," he said.
"I think a few people thought I took a hospital pass but I love a challenge."
He originally thought he would set up the scientific framework for the programme then walk away after about two years, but thanks to a dedicated team of rangers, "stalwart conservationists", he could not do it.
"The team was so well established and committed I felt I would be letting them down if I walked away - that is why we had the results we had - the dedication was first class."
Together, they developed one of the best pest-control operations on the planet, he said.
"It's a magic place and I'm hugely sad to leave my friends and colleagues - they've been like another family."
Despite looking forward to his new job, he does not rule out coming back to New Zealand one day.
"What you can achieve in conservation in New Zealand is enormous. This is the place you want to be to learn new skills in a practical way. It all adds up to making a difference."
