Commentary for Job 39:13

The wing of the renanim rejoices This is the name of a huge bird, called in the language of the Mishnah, Bar Yochni (Bechoroth 57b).

Unlike other birds, the ostrich appears not to care for its young. Fleet of foot but unable to fly despite its bounteous plumage, it nests on the ground. It lays a large number of eggs most of which do not hatch, many being consumed by the chicks that emerge from the few that do. An odd bird, proverbially both stupid and heartless,³¹'...but the daughters of my people are cruel, like ostriches in the desert' (Lamentations 4:3) but it too is part of God’s grand design.

the winged Heb. אֶבְרָה. Every bird is called אֶבְרָה because it flies; i.e., either the bird named “stork,” or the bird called nozah. Note her behavior.