She envisaged a ribbon, a thread, running through the book with north on one side, south on the other.
"So I was looking at these animals and how they have adapted over time to their climate and its seasonal changes. I did it, really, because I wanted to show children how important climate is to these animals, and with rapid climate change, we are demanding they adapt really quickly, and probably quicker than they can."
Sandra is shocked at how many species we have lost over such a short time.
"When I researched the book I had all these ideas of what animals I was going to do and I got terribly excited about some of them."
She has an old 1960s Readers' Digest book on animals, in which she saw the Golden Toad from the cloud forests of Costa Rica.
"They have this fascinating thing where the males all gather round a pond where they chorus to attract the females, really putting themselves at huge risk. Then they disappear after mating. I had this vision of these beautiful gold toads around a pond." She since discovered the toad is extinct.
It was Sarah, the book designer, who noticed Sandra had placed animals sharing a common theme on each page, and Sandra had not realised. It's something for young readers to find and identify.
Sandra has also added the conservation status of each animal – there are five categories: least concern, near threatened, vulnerable, endangered and critically endangered.
"Everybody knows about elephants, but I thought I'd put them in anyway, but it was nice to be able to research the snow leopard, and the dormouse was such a pleasure to illustrate, and these honeypot ants had always fascinated me so they had to go in."
All the creatures started off as watercolour paintings before becoming illustrations in the book and there are two levels of text for different age groups. The hard part for Sandra was what information to leave out.
The book is being produced this month and will be launched at Lockett Gallery on Sunday, March 7, at 3pm, as part of La Fiesta!