Population dynamics are determined by the demographic summation of individual reproductive success. Reproductive success (that is, fitness) is measured by the representation of descendants in the next generation. Many offspring disperse; therefore, the reproductive success of an individual cannot be known without determining the survivorship and reproductive output of their dispersing offspring. The investigator will continue a 28-year study of age, sex, social behavior, reproductive output, pattern of space-use, social organization, and survivorship over the lifetime of males and females from four colonies of yellow bellied marmots. In addition to collecting the basic demographic data necessary for continuity of this longitudinal study, Dr. Armitage will be analyzing data collected over the lifetime of the research. Many rodent populations require control. Control measures are ineffective if those animals that are killed or removed are quickly replaced by immigrants. Because yellow-bellied marmots frequently are agricultural pests, knowledge of the fate of dispersers will contribute to the preparation of effective control measures.
