title: Tonic immobility and shivering in birds: evolutionary implications.
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000502:physiology*; D010856:Columbidae / Q000502:physiology; D004576:Electromyography; D008029:Lighting; D009129:Muscle Tonus; D010369:Pectoralis Muscles / Q000502:physiology; D011187:Posture; D012768:Shivering; D013045:Species Specificity; D013696:Temperature