At the end of nine hundred years, they flew back to Eriu in swan-form, where they met Saint Patrick, who converted them to Christianity. When he baptised them with holy water, they turned into very old people and died. There are two other species of swan in Prydain and Eriu, the whooper swan and the Bewick's swan, which only visit the islands in the winter. Boar hunting is one of the sports of Celtic warriors, and boar forms a staple part of the diet at banquets in the king's hall. Salmon are a common fish in the rivers of Prydain and Eriu, where they spawn in the summer.
Winter is spent at sea, thousands of miles away.
Salmon are not at all dangerous, but are very good to eat. There are several stories of Salmon in Celtic mythology, the most well-known being the story of the Salmon of Knowledge. This was a salmon called Fintan who ate the Nuts of Knowledge before swimming into a pool in the River Boyne. There he was caught by Finegas and given to Finn to cook. Finn burnt his thumb on the salmon as he was turning the spit and licked it, thus gaining great wisdom.