The Bodhisatta was once a fowl. He was the chief of a large flock, and over time a falcon ate all the birds but him. Wanting to eat the Bodhisatta too, the falcon needed to find a way to draw him out of his bamboo thicket. So he landed on a branch, apologized for his past sins, told the Bodhisatta he wanted to be his friend, and invited him to dine together at a place with lots of food. The Bodhisatta told him they could never be friends, and then he gave a sermon about not befriending those who are deceitful, selfish, and walk in evil ways for all the deities living in the forest to hear. He then threatened the falcon with harm if he didn’t leave, so the falcon flew off to a new place.
In the Lifetime of the Buddha
The falcon was an earlier birth of Devadatta, a disciple of the Buddha who became his nemesis. When the Buddha heard some of his disciples talking about Devadatta’s attempt to hire archers to kill him, he told them this story so they knew that Devadatta had also tried to kill him in the past.