A cycle of prevalence of Q-fever antibodies in sheep is confirmed, and possible relationships between sheep, wild mammals and birds in the ecology of Q-fever are exhibited. Carnivores and carrion-eaters, including coyotes (Canis latrans), turkey vultures (Cathartes aura), grey foxes (Urocyon cinereoargenteus), and hawks [Red-tailed hawk (Buteo borealis) and Sparrow hawk (Falco sparverius)] have serological evidence of Q-fever indicating exposure relative to their food habits. Herbivorous mammals and birds have evidence of Q-fever exposure relative to their relationship with sheep: species that share the same pastures as the sheep have a higher percentage with Q-fever antibodies than species inhabiting the protective underbrush or species that are more independent of the activities of livestock. A detailed study of 5 representative wildlife species, including the deer mouse (Peromyscus maniculatus), black - tailed jackrabbit (Lepus californicus), Columbian black-tailed deer (Odocoileus hemionus columbianus), ground squirrel (Citellus beecheyi), and the common red-wing blackbird (Agelaius phoeniceus) indicated that the blackbird has a peak prevalence of antibodies before that of sheep, the black-tailed jackrabbit and the ground squirrel seem to parallel sheep in cyclic responses, and the peak prevalence of Q-fever antibodies in the deer mouse occurs after the peak response in sheep. Deer responses appear to be unrelated to sheep responses.