If you come across a bird’s nest with chicks or eggs, either in a tree or on the ground along the road, and the mother is sitting on the chicks or eggs, you must not take the mother along with the young.
Jewish Publication Society of America Version (JPS1917) - Deuteronomy 22:6 >If a bird's nest chance to be before thee in the way, in any tree or on the ground, with young ones or eggs, and the dam sitting upon the young, or upon the eggs, thou shalt not take the dam with the young;