This is the 1979 Bookclub Edition of Transfigurations, a 1979 science fiction novel by Michael Bishop. Expanded from his Nebula Award-nominated 1971 novella "Death and Designation Among the Asadi," the book is a work of "alien anthropology" that follows a daughter's quest to find her missing anthropologist father. 
 
The story is set on the planet Bosk'veld, home to a strange, ape-like alien species known as the Asadi. 
The novel's protagonist, Elegy Cather, is an anthropologist who travels to Bosk'veld to investigate the mysterious disappearance of her father, Egon Chaney. He was last known to be deeply involved in studying the complex rituals and devolved culture of the Asadi.
The Asadi are a hominoid species with rainbow-colored eyes whose culture has devolved from a highly technological one to a primal state of complex and seemingly incomprehensible rituals.
 Elegy, accompanied by her father's former colleague Thomas Benedict, uses her father's field notes, journals, and a genetically-adapted intelligent ape named Kretzoi to retrace his steps and unravel the mystery of the Asadi. As Kretzoi infiltrates the Asadi society, the book probes the true nature of the aliens and explores questions of humanity.