As per the Ramayana Aranyakanda Sarga 14, Kashyapa married eight daughters of the prajapati Daksha, one of them being Tamra. They had five daughters – Kraunchi, Bhasi, Shweni, Dhritarashtri, Shuki. Kraunchi gave birth to owls, Bhasi to Bhasas, Shweni to eagles and vultures, Dhritarashtri to swans, kokas etc, and Shuki to Shukas, or birds.

Once the devas desired Shiva to produce a son to kill Tarakasura. Shiva agreed. But though a hundred years passed, Shiva and Parvati remained immersed in each other. The world was nearing collapse and the devas, as per Brahma’s instruction asked Agni to distract the couple. Agni knew that it was impossible and hid in the ocean. The animals in the water were being boiled by Agni’s heat and gave away his hideout to the devas. Agni cursed that they would all be mute henceforth and then hid in the Mandara mountain. The birds there informed the devas and Agni cursed that their tongues would henceforth be folded inside. The birds begged for mercy and Agni blessed that though they wouldn’t be able to speak, their voices would be sweet as per Kathasaritasagara Lavanakalambaka Taranga 6, and Bhashabharata Anushasanaparva Chapter 85.