Auditory disturbances promote temporal clustering of yawning and stretching in small groups of budgerigars (Melopsittacus undulatus)

Journal of Comparative Psychology (2012) - Comment
pubmed: 22268553 doi: 10.1037/a0026520 issn: 1939-2087 issn: 0735-7036

Michael L. Miller, Andrew C. Gallup, Andrea R. Vogel, Anne B. Clark