[Scientist answers readers: the functional importance of the gravel found in the stomachs of birds].
D000818:Animals; D002645:Chickens; D004063:Digestion; D005895:Gizzard, Avian / Q000502:physiology; D013278:Stomach, Avian / Q000502:physiology*
Vam otvechaet uchenyĭ: o funktsional'nom znachenii graviia, obnaruzhivaemogo v zheludkakh ptits.