Lieutenant-Colonel J. Stevenson-Hamilton, First Warden of the Kruger National Park, South Africa, wrote a preface to the book "Sanctuary", printed in 1942.

"The destruction of any human work of art - a beautiful picture, a statue, or a splendid piece of architecture - is a serious catastrophe, but it is not irremediable; such things are the work of man, and what man has done once, he can do again : his genius can create other equally-beautiful pictures or statues or splendid pieces of architecture to replace those lost.

It is not so when a natural species has been destroyed. No utmost effort of man can ever again bring it into being. Once gone, it is lost irretrievably, and the world is permanently the poorer."