There were many days when Chandler Robbins rose before the sun to partake of the dawn chorus – the coo of the mourning dove, the dulcet strain of the American robin, the fluting of the wood thrush.

Among fellow birdwatchers, Robbins, who died March 20 at 98, was revered as a father of modern ornithology. He was the principal author of “Birds of North America: A Guide to Field Identification,” a bible for millions of birding enthusiasts.

Robbins documented avian life around the world, including on the Pacific island of Midway, where in 1956 he tagged a young Laysan albatross who came to be known as Wisdom. She is the oldest known wild bird, a matriarch who laid an egg as recently as December.

But for more than six decades, he worked primarily in the environs of Washington, D.C., as an ornithologist at the Patuxent Research Refuge in Laurel, Maryland. In the 1950s, he documented the damage wrought by the pesticide DDT, including its thinning effect on osprey and eagle eggshells. Rachel Carson, a colleague at the time, relied on his research for her 1962 environmental manifesto “Silent Spring.”

An early champion of citizen science, Robbins founded the North American Breeding Bird Survey, an initiative that has grown since its founding in 1965 to involve thousands of volunteer birders in an annual effort of exacting rigor to measure the continental bird population. It is one of the two most significant avian monitoring programs of its kind. Robbins participated in the other, the National Audubon Society’s Christmas Bird Count, for more than 80 years, said its director, Geoff LeBaron.

“It is not an exaggeration at all to call him one of the giants of 20th-century ornithology and bird conservation,” said John Fitzpatrick, director of the Cornell Lab of Ornithology in Ithaca, New York, said.

Robbins said that his first conscious memory was of a display of mounted birds at the library in Belmont, Massachusetts, where he was born Chandler Seymour Robbins on July 17, 1918. His father was a birder, and Chandler’s brother Samuel also grew up to be a noted ornithologist.

He received a bachelor’s degree in physics from Harvard University in 1940 and a master’s degree in zoology from George Washington University a decade later.

He declared himself a conscientious objector during World War II and joined the Civilian Public Service, work that brought him to the Patuxent Research Refuge. He retired in 2005 but continued field research until recently.