How "fixed" is the fixed action pattern?
D000819:Animal Communication; D000818:Animals; D001522:Behavior, Animal; D001717:Birds; D005260:Female; D005824:Genetics, Behavioral; D007323:Instinct; D008297:Male; D009068:Movement; D009626:Terminology as Topic; D014422:Turkeys; D014828:Vocalization, Animal