Elephants are among the earth's most sentient beings. They remember, they experience grief and joy, fear and love. Indeed, as our knowledge of these extraordinary creatures increases, the more they transcend all preconceptions of animal behavior. Michael "Nick" Nichols, longtime photographer for "National Geographic" as well as the magazine's editor-at-large for photography, has been working with African elephants for more than 20 years. In "Earth to Sky, " he tells their story through poignant images that bring us directly into their habitats--lush forests and open savannas, or stark landscapes ravaged by human intervention--to observe the animals' daily engagements and activities. Nichols' photographs are accompanied by the words of such celebrated figures in the field of conservation as Iain Douglas-Hamilton, J. Michael Fay, Peter Matthiessen, Cynthia Moss, David Quammen and many others. In addition, Nichols engages us in his photographic journey with personal and informative introductions to each of the book's four chapters--exploring life in the wild, the ivory trade, family interactions and programs for orphaned elephants. The survival of elephants is under dire threat from territorial conflicts between man and nature, and most immediately from the market for ivory. More than 25,000 elephants are slaughtered each year, and their ivory is sold at astronomically high prices to countries such as China, Japan, the Philippines and Singapore. Sadly, all signs point to a tragic conclusion for these wise, complex creatures, should humans continue to exploit them. "Earth to Sky" is an urgent call for us to bring that process to a halt, while we still can. Michael Nichols (born 1952) is an award-winning photographer whose work has taken him to the most remote corners of the world. He became a staff photographer for "National Geographic" in 1996 and was named editor-at-large in January 2008. From 1982 to 1995 he was a member of Magnum Photos. His previous books with Aperture include "Gorilla" (1989) and "Brutal Kinship" (2005).