Hyginus Fabulae, 53 Asterie.
When Jupiter was enamored of Asterie, the Titan's daughter, she despised him. For this reason she was transformed into the bird called the ὄρτυξ (the quail), which we call in Latin the cortunix. He threw her into the sea and from her was born the island that is now called Ortygia. (2) This island was movable. Upon it, later, Latona (Leto) was carried away by the North Wind at the order of Jupiter — this was at the time that Python was pursuing her; and there Latona grasped the olive tree and gave birth to Apollo and Diana. This island later came to be known by the name of Delos.
— translation RTMacfarlane
53. Asterie
Iouis cum Asterien Titanis filiam amaret, illa eum contempsit; a quo in auem ὄρτυγα commutata est, quam nos coturnicem dicimus, eamque in mare abiecit, et ex ea insula est enata quae Ortygia est appellata. (2) haec mobilis fuit; quo postea Latona ab Aquilone uento delata est iussu Iouis, tum cum eam Python persequeretur, ibique oleam tenens Latona peperit Apollinem et Dianam; quae insula postea Delos est appellata.