Markandeyapurana 9.11

9.11

anyo 'nyaśāpāt tau prāptau tiryaktvaṃ paramadyutī /
vaśiṣṭhaḥ sa mahātejā viśvāmitraśca kauśikaḥ //

The birds spoke:
Hearing the curse, the glorious Viśvāmitra likewise, Kuśika’s descendant, inflicted the counter-curse, “Do thou also become a mainā.”[2] Both those most illustrious sages were transformed into birds through their mutual curses, the glorious Vaśiṣṭha and Viśvāmitra, Kuśika’s descendant.