There is a story about an American Indian who found an eagle's egg and put it into the nest of a prairie chicken. The eaglet hatched with the brood of chicks and grew up with them.
So the changeling eagle never gave it a second thought. Throughout its entire life the changeling eagle pride itself as being a prairie chicken and it died thinking it was a prairie chicken. (Story Taken From: The Christophers, Bits & Pieces)