Parashas Vayikra · Aliyah 2 · Passuk 14
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim (olah stated to exclude bird shelamim).
English: “And if from the fowl, an olah” — why state “olah”? To teach you: a bird may be an olah, but not a shelamim.
Custom (specification of offering type).
Birds are brought as olah (and chatas elsewhere), not as shelamim.