[4] His mother was Constance Baillie Rose of Scottish descent while his father was Louis Arthur Dillon Ripley, a wealthy real estate agent who drove around in an 1898 Renault Voiturette.

Both his paternal grandparents, Julia and Josiah Dwight Ripley, died before he was born but he was connected to them through Cora Dillon Wyckoff.

Great Aunt Cora and her husband, Dr. Peter Wyckoff, often hosted young Ripley at their Park Avenue apartment.

Cora's and Julia's father (his great-grandfather) and partial namesake was Sidney Dillon, twice President of the Union Pacific Railroad.

"Louis told me we ought to have a lawyer in the family," he has said, "but I really hated the idea, and in the summer of 1936, after graduating from college, I resolved to abandon all thoughts of a prosperous and worthy future and devote myself to birds, the subject I was overpoweringly interested in.

They stayed at the Taj Mahal Hotel in Bombay and then went to Kashmir and included a walking tour into Ladakh and western Tibet.

[8] He decided that birds were more interesting than law and after graduating from Yale in 1936 he was advised by Ernst Mayr that "the most important thing you can do is get a sound and broad biological training."

During World War II, he served under William J. Donovan ("Coordinator of Information") in the Office of Strategic Services, the predecessor of the Central Intelligence Agency.

In the early days Ripley acted as liaison with the British Security Coordination led by Sir William Stephenson at the Rockefeller Center.

Nehru came to hear of this from an article in The New Yorker and was furious, leading to a difficult time for his collaborator and coauthor, Salim Ali.

He noted that the Smithsonian sent a scholar to India for anthropological research who unknown to them was interviewing Tibetan refugees from Chinese-occupied Tibet but went on to say that there was no evidence that Ripley worked for the CIA after he left the OSS in 1945.

He was awarded honorary degrees from 15 colleges and universities, including Brown, Yale, Johns Hopkins, Harvard, and Cambridge.

[21][22][23] Ripley successfully defended the National Museum of Natural History against a lawsuit that objected to the Dynamics of Evolution exhibit.

[9] Ripley had intended to produce a definitive guide to the birds of South Asia, but became too ill to play an active part in its realisation.

However, the eventual authors, his assistant, Pamela C. Rasmussen, and artist John C. Anderton, named the final two-volume guide as Birds of South Asia.

In 1985, Dillon and his wife, Mary Livingston Ripley, donated the portion of their estate that is today the Conservancy to the non-profit organization that continues to operate it.

Today the Conservancy remains one of the only facilities in North America dedicated to breeding and rearing rare and endangered waterfowl and houses over 90 species of birds, totaling over 500 individuals.