The origin of the turkey

Far away across the galaxy, there is a planet inhabited by turkeys.
Its name? Than'Giv.
Here, the turkey is the most intelligent creature. They have built vast empires and made stunning progress in their space travel program. The very best from their ranks were trained as ambassadors to the stars, for the turkeys hold a strong belief that they are not the only life in the universe.
And so their rockets were launched. Each destined for a different galaxy.
But on one rocket, there was a malfunction with the life support system.
The malfunction effected the mind of those in cryo-hibernation. The mind slowly began to degenerate, growing ever worse the longer one was maintained by the life support.
By the time the rocket landed on the strange blue planet that had shown signs of life on the turkey's scanner, the crew had become nothing more then animals.
Somehow managing to escape their craft, the wild turkeys fled into the strange wilderness.
Generations later, their descendants have never recovered their ancestors intelligence.
They now have become the main course for a celebration held by the natives of the blue planet.