Food, song and speciation.
Ryan
M J
MJ
D000222:Adaptation, Physiological; D000818:Animals; D001502:Beak / Q000033:anatomy & histology; D005075:Biological Evolution; D004032:Diet; D004463:Ecology; D005247:Feeding Behavior; D005260:Female; D008297:Male; D012726:Sexual Behavior, Animal; D020308:Songbirds / Q000033:anatomy & histology / Q000502:physiology*; D014828:Vocalization, Animal