Leviticus 1:14-16

14“If you present a bird as a burnt offering to the Lord, choose either a turtledove or a young pigeon.

15The priest will take the bird to the altar, wring off its head, and burn it on the altar. But first he must drain its blood against the side of the altar.

16The priest must also remove the crop and the feathers and throw them in the ashes on the east side of the altar.