Genesis 7:3

“Of fowls also of the air by sevens, the male and the female; to keep seed alive upon the face of all the earth.”

KJV

Meaning

Birds are included in greater numbers so that their life will continue on the earth after the flood.

The verse speaks in broad ancient creature categories and does not attempt to provide a modern biological classification system.

Preservation in Genesis 7 is future-oriented: life is carried through judgment so that it can continue afterward.