Sentence:  Among the Miwok certain birds [...] are represented in the God-impersonating Cult. In the third stratum dances the spirits impersonated in the "kuksuyu" and "kilaki", which elsewhere are regarded as anthropomorphic deity and dragon respectively, are by the Central and some Northern Miwok identified with birds, the "kuksuyu" with a shore bird, the "kilaki" with a hawk. This is perhaps a manifestation of the tendency to <WSD>avianize</WSD> even the new dances of the third or Ghost-Dance stratum. 
Meaning of the word marked with <WSD> tags:  To make avian; to make bird-like or into a bird.