English: Turtledoves: mature and not young; young pigeons: young and not mature — excluding the onset of yellowing in either, which are invalid.
In the sugya: The two species names carry opposite age windows. Torim are valid only when mature; bnei yonah only when young. The transitional stage of yellowing is excluded from both windows and is therefore pasul for either designation.
Type of Learning
Miyut of age windows from the species names and the exclusion of the transitional stage.
What Is Learned
Torim must be mature; bnei yonah must be young. The onset of yellowing in either species falls outside both windows and renders the bird invalid for olah. The verse’s dual designation is the source of the two distinct, non-overlapping age requirements.