The arayanna were described as having a heavenly abode on Manasasaras, one of the Himalayas. Ara denoted royalty. The swans did not like rain, so they came to earth when it rained in their heavenly abode and returned as soon as rain began on earth. Their parentage was traced to KasSyapa by his wife Tamra through her daughter Dhritarashthri. Valmiki’s Ramayana stated that this lineage alone gave the swan its divinity (devatva).
Swans were at first black and white, according to a myth in the Uttara Ramayana, but pure white was given as a blessing from the god Varuna, who took their form to hide from the great demon Ravana. (The gods had assembled for a sacrificial meal and had to change into the shape of various birds when Ravana came to attack them.) The swan was blessed by Varuna to be as white as milk.
There are many stories about the arayanna. A swan was once stuck in a water tank, and Prince Nala found and captured it, but then took pity on the trembling bird and released it. The arayanna was so happy that it flew to the next kingdom and helped in gaining Princess Damayanti as Nala‘s wife.
The swan could be used in a more obvious moral lesson. A story was told to Bhishma: why this sage is so unreliable. An old arayanna lived by the sea and preached righteous actions to the birds of that region. Then because of a famine the birds needed to look farther away for their prey, so they entrusted their eggs to the swan, and he grew fat eating the very eggs he had promised to watch. Finally one of the birds noticed the declining number of eggs and told the others, and they killed the deceitful arayanna. This theme of reversal in the myths—of a king or priest or even a god failing to be righteous—illustrated the importance of following dharma (ethical duty) just as clearly as if the story had given a positive example.
Swans (hamsa or arayanna) were considered to be celestial birds having the capability of separating water and milk. They were often used in Vedantic literature metaphysically as a metaphor for one who had the ability to distinguish between the material and the spiritual. Even Krishna would be called a hamsa, as was Shri Ramakrishna in the modern period.
