Midrasz do Kapłańska 1:14

1) (Vayikra 1:14): "And if from the fowl, an olah is his offering": "the fowl, an olah," but not peace-offerings. (Without the exclusion we might reason:) Now is this not a kal vachomer? If an olah, which may not be brought from females as (they may be brought) from males, may be brought from fowl — peace-offerings, which may be brought from females as from males, how much more so should it be permitted to bring them from fowl! It is, therefore, written "the fowl, an olah" — and not peace-offerings. These are the words of R. Shimon.

1) I might think that just as a bird cannot be brought as a communal gift-offering, so it cannot be brought as a gift of two (i.e., in partnership); it is, therefore, written (superfluously) "and he shall offer" (Ibid.) to teach us that it can be brought as a gift of two.

1) (Vayikra 1:15): "And the Cohein shall bring it near to the altar"): Why "And he shall bring it"? (In context the "it" is superfluous). Because it is written (Vayikra 1:14): "And he shall offer his offering from the turtle-doves or from the young," I might think that he could offer no fewer than two; it is, therefore, written "And he shall bring it near" — even one suffices.