I think coyotes are more likely to contract than buzzards/vultures simply because coyotes are mammals and are genetically more similar to cervids than are birds. However, I'm not a geneticist and I'm certainly not a neurobiologist. I'm not sure how similar the protein structures are between canid species, cervids and birds. Some mammalian species show a resistance to misfolding of the protein that causes cwd
Unfortunately if the articles I've read recently are any indication humans are susceptible to misfolded proteins- as in cjd) even if there hasn't been a documented case of cwd transmission yet.