His book, which will be officially launched next Tuesday at 5pm upstairs at the Hastings Central Library, is titled Dare To Escape and tells the story of a baby gecko called Houdini whose young life is shattered by the natural hostility of the wild - in the form of Kotare the kingfisher, who stalks and takes his parents.
The baby gecko takes to the big world around him and builds on his strength to survive in the adventures he encounters, and lives up to his name of Houdini.
It is a story which takes place within the harmony of wildlife and the natural bush - two things about which Mr Tregonning is passionate. He said it was a story for all New Zealanders from age 5 upwards.
"Even grandparents with a desire to encourage their younger family members to read will enjoy the forest and bird setting - it's a blend of fact and fiction and displays how precious this creature is," Mr Tregonning said.
The children he had introduced to the tree green geckos he sometimes took along as part of natural science lessons agreed.
"They are tickled pink to see them up close and to hold them - and it is a real benefit to be able to do that."
Mr Tregonning got in touch with the Department of Conservation 10 years ago, requesting permission to breed geckos as a licensed holder.
The answer was yes and since starting the programme he has visited 31 schools across Napier and Hastings with his little green visitors.
He said he felt a responsibility to be the "voice" of the gecko in the world in which it now lived.
" ... allowing the children to encounter the tree green gecko has given them the opportunity to enjoy the really cute features of a reptile which is rarely found in New Zealand.
"It is the gentle, cool and non-threatening touch of the species that gets them - and they look like they are smiling."
The book, illustrated by artist Peggy Hope, is Mr Tregonning's third in a series of "dare to" titles and will be on sale at Beattie and Forbes in Napier, Poppies in Havelock North and Plaza Books in Hastings.