Louis D. DeMouy, 72, a retired statistics and data expert at the U.S. Energy Department, who was also a leader in bird-watching groups, died Nov. 8 at ManorCare Potomac nursing facility. He had mesothelioma, a form of cancer, said his wife, Jane DeMouy.

Louis Decker DeMouy was born in Washington and was a graduate of Gonzaga College High School. He received a bachelor’s degree in economics from Georgetown University in 1963 and later served two years in the Army. He received a master’s degree in economics from Georgetown in 1970.

After a series of early jobs with federal and regional agencies, Mr. DeMouy worked at the Securities and Exchange Commission from 1972 to 1975. He then joined the Federal Energy Administration, which later became part of the Energy Department.

From 1977 until his retirement in 2006, he worked at the Energy Information Administration, where he managed national and international energy information programs. He provided data and analysis for departmental studies and was the U.S. representative to many international energy organizations and gatherings. In 1997, he became director of the Integrated Energy Statistics Division. He was a consultant after his formal retirement.

Mr. DeMouy, who lived in Chevy Chase, twice served as president of the Montgomery Bird Club of the Maryland Ornithological Society. He chaired gatherings of the Maryland society and led bird-watching walks for the Audubon Naturalist Society in Chevy Chase and at Kenilworth Park and Aquatic Gardens in the District.

He was a volunteer reading mentor in D.C. schools and volunteered at food pantries. He also ran several times in the Marine Corps Marathon and 10-mile running events.

Survivors include his wife of 47 years, Jane Krause DeMouy of Chevy Chase; three daughters, Maura DeMouy of Bethesda, Amy DeMouy of Kensington and Bridget DeMouy of New York City; seven sisters, Ruth Anne DeMouy-Hunt of the U.S. Virgin Islands, Mary Jane Poulter of Farmville, Va., Frances DeMouy of New York City, Rosemary D. Podany of Glen Burnie, Dorothy DeMouy of Phoenix, Helen DeMouy of Denver and Caroline D. Mayo of Dublin, Ohio; four brothers, Richard DeMouy and Joseph DeMouy, both of San Antonio, John DeMouy of Huntingtown and Patrick DeMouy of Columbia, S.C.; and four grandchildren.

— Matt Schudel