Ramban, Deuternonomy 22:6

When you chance upon a bird’s nest- This mitzvah is also understood along with the mitzvah of “oso v’es b’no” (not to slaughter an animal and its offspring on the same day – Leviticus 22:28). Because the reason for both mitzvot is to prevent us from becoming cruel and unmerciful. Moreover, scripture does not allow slaughter that would uproot a species, even though slaughter is permitted of individuals of that species. And one who kills the mother and her children on the same day, or who takes them from the wild where they are free to fly, it is as if that person is cutting off that species. [Translation by Sareet Benayahu]