Donald J. Frederick, 81, a retired science writer for the news service of the National Geographic Society, died of complications from pneumonia Nov. 18 at Sibley Memorial Hospital in Washington. His death was confirmed by Barbara Moffet, a National Geographic Society spokeswoman.

Mr. Frederick joined the National Geographic Society news service in 1965 and retired in 1995. His work ranged from stories about the naked mole rat to subatomic neutrinos. Many of his stories were published in newspapers around the country.

In retirement, Mr. Frederick did freelance writing for several publications, including Popular Science and Chemistry.

A resident of Washington, Donald James Frederick was born in Detroit. He graduated from Georgetown University in 1953 and also studied at the University of Oslo and the University of Madrid, where he received a language certificate.

His early jobs included writing for American Aviation Publications in Washington and for McGraw-Hill in New York.

He lived in the District and was a member of the Cosmos Club, National Press Club and National Association of Science Writers. He served on the board of the D.C. Science Writers Association.

His wife of 46 years, Andree Beaudoin Frederick, died in May.

Survivors include a daughter, Felice Frederick of Arlington County.

— Bart Barnes