Donald R. Griffin, a zoologist who solved the mystery of how bats navigate in the dark and later transformed the study of animal behavior by suggesting animals were intelligent and could reason, died Nov. 7 at his home in Lexington, Mass. He was 88.
Griffin made his breakthrough on bat sonar in 1938 while still an undergraduate at Harvard University.
Working with fellow student Robert Galambos, he used special microphones to prove that bats "see" in the dark by emitting ultrasonic sounds above the range of human hearing and then listening for the echoes to reveal details about objects around them. Such information is so precise that some species of bat use it to find -- and eat -- tiny flying insects.
Griffin later coined the widely used term "echolocation" for the process and wrote a 1958 classic book on the topic, "Listening in the Dark." He became known as "Batman" among his colleagues and students.
"He was one of the great American scientists of the 20th century," said Fernando Nottebohm, a noted animal behavior expert and longtime colleague of Griffin at Rockefeller University in New York. "He had a very bold mind."
Griffin also pioneered the use of rigorous techniques to study animals in their natural environments instead of in artificial laboratory settings, which were easier for scientists to control but often interfered with the ways animals behaved normally, Nottebohm said.
To study how seabirds could soar without flapping, for example, he followed birds out to sea and later flew kites on the beaches of Trinidad.
Throughout his career, the topic that intrigued Griffin the most was the question of whether animals were aware of what they were doing, or possessed consciousness. In a 1976 book, "The Question of Animal Awareness," Griffin suggested that animals, like humans, might be capable of thought and awareness.
Though the issue had been raised by a handful of scientists in previous centuries and was the subject of a book by Charles Darwin, the topic of animal consciousness was somewhat taboo among scientists at the time Griffin raised it. Critics argued that Griffin's examples of animals apparently showing conscious thought were anecdotal and attributed human qualities to animals without rigorous proof, just as devoted pet owners did.
The topic remains controversial to this day. Many scientists argue that animals, like computers, can be programmed genetically to perform complex behaviors without consciousness.
"He knew he was taking risks and was on thin ground, but he thought it was a legitimate area for scientific exploration," Nottebohm said. With tenure at Rockefeller University, a membership in the National Academy of Sciences and an international reputation for his work on bats, "he didn't have to apologize," Nottebohm said.
Griffin argued that scientists needed to think harder about how they defined consciousness and that the sophisticated and adaptive behaviors of some animals -- herons using bait while fishing or apes using computer keyboards to send messages to their keepers -- left open the possibility of animal consciousness.
Griffin railed against the idea that animals were comparable to human sleepwalkers and said many who refused to consider the topic were succumbing to a "self-inflicted paralysis of inquiry." Griffin's imprimatur "made talk about animal minds respectable," said Mark Bekoff, a biologist at the University of Colorado and expert in "cognitive ethology," or the study of mental experiences of animals.
Griffin spent his final years in Lexington, Mass., working at Harvard University's Concord Field Station. Ever intrigued by animal communication, he was using microphones to study the noises made by beavers in their lodges.
Griffin was born in Southampton, N.Y., and graduated from Harvard in 1938. He received a master's degree from Harvard in 1940 and a PhD in 1942.
Griffin's first academic position was at Cornell University in 1946. He rose to the position of professor and then moved to Harvard, where he worked from 1953 until 1965. He joined the Rockefeller University faculty in 1965 and stayed until his 1986 retirement.
His wife, Jocelyn Crane, a researcher and assistant to explorer William Beebe, died in 1998.
Griffin is survived by two daughters, Janet Abbott of Arlington, Mass., and Margaret Griffin of Montreal, and a son, John, of Brighton, Mass.