According to Māori tradition, Paikea is an ancestor of Ngāi Tahu and Ngāti Porou, Māori tribes in the South Island and east coast of New Zealand's North Island. Paikea is the name assumed by Kahutia-te-rangi because he was assisted by humpback whales (paikea) to survive an attempt on his life by his half-brother Ruatapu.
Ruatapu is shamed
Ruatapu became offended when his father Uenuku elevated his older half-brother Kahutia-te-rangi (later known as Paikea) ahead of him. When Ruatapu was about to use a comb belonging to Kahutia-te-rangi, Uenuku rebuked him, pointing out that Kahutia-te-rangi was of high rank while Ruatapu was of low birth (because his mother was a slave wife).
Angry and ashamed at his father's disparaging comments, Ruatapu built a canoe, or waka. When it was finished, he lured Kahutia-te-rangi and a large number of the other sons of Uenuku, all of them young men of high birth, aboard his canoe, and took them out to sea to drown them. He had knocked a hole in the bottom of the canoe, temporarily plugging it with his heel. When far out at sea, he removed his heel, and the canoe sank. Ruatapu then went to each of the young men in turn, and drowned them. However, Kahutia-te-rangi recited an incantation invoking the Southern Humpback whales (paikea in Māori) to carry him ashore.  Kahutia-te-rangi was the sole survivor of his brother's evildoings and assumed the name Paikea as a memorial of the assistance he received from the whales.
The Waves of Ruatapu
The episode where Ruatapu threatens to return as the great waves of the eighth month may explain other accounts where Ruatapu is portrayed as having invoked a great flood. Such accounts or conclusions may be the result of Christian influence. According to Ruatapu's accountIn the Ngāti Porou accounts translated by Reedy (1993, 1997), Ruatapu shouted out to Kahutia-te-rangi that he would return to fight him: "The great waves of the eighth month, they are me! I am then approaching!" In an endnote, Reedy says
In the eighth month of the Māori calendar, in the early summer, large waves known as ngā tai o Rangawhenua, Rangawhenua's waves, sometimes break upon the shore on the East Coast. In this episode Ruatapu announces that in the eighth month he will take this form, and follow Paikea.
- "The Whale Rider" is based on this myth.
- The Whale Rider—a book (by Witi Ihimaera) and film inspired in part by the story of Paikea and Ruatapu.
- In other accounts, the rebuke came when Ruatapu dared to walk on the roof of Uenuku's house.
- In some versions, Kahutia-te-rangi became a whale; in others, he rode on a whale's back.
- The murderous Ruatapu was himself drowned in some accounts.
- Reedy 1993:143, Reedy 1997:85 is similar.
- 1993:231, note 101.
- Craig, R. D. Dictionary of Polynesian Mythology (Greenwood Press: New York, 1989), 198–9, 237.
- Reedy, Anaru, Ngā Kōrero a Mohi Ruatapu, tohunga rongonui o Ngāti Porou: The Writings of Mohi Ruatapu (Canterbury University Press: Christchurch, 1993), 142–146.
- Reedy, Anaru, Ngā Kōrero a Pita Kāpiti: The Teachings of Pita Kāpiti (Canterbury University Press: Christchurch, 1997), 83–85.
- Paikea, a Māori folk song, with English translation and discussion.