Dwight R. Chamberlain studied the language of crows and ravens and helped to explain the intricate vocal cues they use in fighting, feeding and social interactions. In the 1960s, Mr. Chamberlain did early research on common crows, recording them so the could classify and understand the functions of their calls. He found at least 11 distinct calls, known as vocalizations, and described some of them in a thesis for his master’s degree at Virginia Polytechnic Institute and State University in 1967.
Among the calls, he identified signals for assembly, dispersal and hunger and a plaintive call made by crows that are dying. Mr. Chamberlain reported that the birds made a squalling call as an emergency signal for help, intended to summon other crows quickly. More elusive were the sounds of courtship, which he said were extremely difficult to record because of the crow’s secretive nature.
With another researcher, George W. Cornwell, Mr. Chamberlain published the findings as part of an influential paper, “Selected Vocalizations of the Common Crow,” in The Auk, a journal of the American Ornithologists’ Union, in 1971.
The classifications listed in the paper remain important in the field, said Kevin J. McGowan, an ornithologist who studies the social behavior of American crows, also called the common crow, and fish crows at the Laboratory of Ornithology at Cornell University.