Henry's first book Lonesome George: The Life and Loves of a Conservation Icon was published by Macmillan Science in April 2006, was longlisted for the 2006 Guardian First Book Award and shortlisted for the Royal Society's prestigious General Book Prize. The paperback was published in May 2007. Here are some of the nice things some very generous people had to say about it:

"This astonishing story of survival tugs at the heartstrings. If Darwin were alive today he would be fascinated by Henry Nicholls' splendid account of this solitary survivor from Pinta Island. A must for anyone who cares about extinction or has a soft spot for the remarkable history of a very singular animal," Janet Browne, author of Charles Darwin

"Nicholls is surely set to become an author of many more fascinating science books. In many ways, this book is what good science writing is all about - explanation through a ripping narrative," Steve Connor, The Independent

"Not simply the story of a tortoise but the tale of that icon of evolution, the Galápagos archipelago, and of the heroics and (sometimes) seeming futility of the conservation movement. The science is compelling, the tone is light - highly recommended," Olivia Judson, author of Dr. Tatiana's S@x Advice to All Creation: Definitive Guide to the Evolutionary Biology of S@x, writing in Seed Magazine

"This is a wonderful tale of an almost mythical beast. Rich in historical detail George's story is one of pathos, despair and hope with some quirky reproductive biology thrown in for good measure. Henry Nicholls has done us all a service, reminding us of the fragility of life in general and of one very special chelonian in particular. Essential reading," Tim Birkhead FRS, author of Promiscuity and The Red Canary: The Story of the First Genetically Engineered Animal

"When tortoises were common on the Galapagos island of Pinta, sailors ate them. When they became rare, collectors pickled and stuffed the last few, "for science". Now it seems that only one is left - the huge and lugubrious Lonesome George - there is talk of applying the most heroic high tech, cloning and the rest, to keep his lineage going. It is a cracking tale - and crackingly well told. It is also salutary. Giant tortoises are indeed extraordinary - but not as strange as human beings," Colin Tudge, author of The Secret Life of Trees: How They Live and Why They Matter

"The literary device of placing a reptilian icon at the centre of a dynamic play about science, conservation and our attitudes to nature results in a highly readable book that has much to say about the ways we flounder around in our attempts to protect things that seem important to us," Nature

"Well written and fascinating — Nicholls’ passion for his subject and sense of humour are always evident," Times Literary Supplement

"Conscientious, comprehensive and balanced. Everyone with an interest in conservation should read this account and consider its implications," Trends in Evolution and Ecology

"Conscientious, comprehensive and balanced. Everyone with an interest in conservation should read this account and consider its implications," Trends in Evolution and Ecology

"Manages to package human drama, reproductive biology and a conservation message with humour and exemplary clarity," Folha de Sao Paulo

“Highly readable. I encourage you to read this succinct book and pass it on to your colleagues, even children," EMBO Reports, Professor Jeffrey Powell, Yale

"In terms that are at once accessible and breezy, he makes an unequivovcal case for the sole known remaining individual of the Galapagos giant tortoise subspecies, Geochelone nigra abingdoni...Nicholls is a master reconteur...the chapters themselves are marvels of elucidation...Nicholls' effort is both timely and redoubtable, and demands critical attention now," John Matthew, History and Philosophy of the Life Sciences

"Endlessly interesting and chockful of humour," Stirling Observer