Leviticus 1:14-16

14And if his offering to Jehovah be a burnt-offering of fowls, then he shall present his offering of turtle-doves, or of young pigeons.

15And the priest shall bring it near to the altar and pinch off its head and burn it on the altar; and its blood shall be pressed out at the side of the altar.

16And he shall remove its crop with its feathers, and cast it beside the altar on the east, into the place of the ashes;