E.O. Wilson, the pioneering US scientist, professor and author whose clarion call to protect Earth earned him the nickname "Darwin's natural heir," has died at age 92, his foundation said Monday.

Wilson was an award-winning biologist and research professor and later professor emeritus at Harvard University, and has been described as the world's leading expert on myrmecology, the study of ants.

He was the author of hundreds of scientific papers and more than 30 books, two of which won him Pulitzer Prizes for nonfiction: 1978's "On Human Nature, and "The Ants" in 1990.

"Ed's holy grail was the sheer delight of the pursuit of knowledge," said Paula Ehrlich, president of the E.O. Wilson Biodiversity Foundation and co-founder of the Half-Earth Project.

"A relentless synthesizer of ideas, his courageous scientific focus and poetic voice transformed our way of understanding ourselves and our planet.

"His greatest hope was that students everywhere share his passion for discovery as the ultimate scientific foundation for future stewardship of our planet."

Wilson, who died Sunday in Massachusetts, had become renowned for his advances in global conservation, and advised preeminent scientific and conservation organizations.