Determination of age, age structure, and mortality of the pika, Ochotona princeps (Richardson)

Determination of age of pikas (Ochotona princeps Richardson) by counting adhesion lines in periosteal bone of the lower jaw is described. Pikas attain a maximum age of at least 7 years in Alberta and Colorado. Estimated yearly losses of adults did not differ significantly between sexes, years of the study, or among collecting areas, and averaged 46%. Age-specific rates of mortality were greatest in the 0–1 and 5–7 year age groups and the general mortality pattern was similar to those reported for other mammals.