Gabriel Mindlin and Ama Amador of the University of Buenos Aires have been investigating that idea. Zebra finches are song learners and implanted electrodes indicate that their sleeping song movements are fragmented, disjointed and sporadic, “rather like a dream” Mindlin says. Great Kiskadees have a more instinctive song with limited learning capacity. Mathematical analysis converting their muscle movements during sleep into audible sounds indicated “quick, identical note syllables” sometimes combined with a flash of head feathers which is a threat that occurs during territorial disputes when they are awake. Amador noted the loud and aggressive sounds were “more like a nightmare than a dream.”
David Margoliash of the University of Chicago, whose earlier work identified the song-learning brain regions, says the results agree with his own observations of sleeping birds’ neurons. But he stops short of saying this sleep activity is “dreaming” and feels more research, including whether birds experience rapid eye movement (REM) sleep, is needed.
Based on a November 2024 article in Scientific American written by David Godkin.