Methods for constructing a life-table and budget for a species are described, and the various methods for the analysis of stage-frequency data reviewed. Stage-frequency data comprise counts of the individuals in different development stages in samples taken from a population over a period of time. The analysis of stage-frequency data to estimate the durations of the stages, the numbers entering stages, and survival rates is described. Examples of survivorship curves are presented, and the calculation of population growth rate described. Analysis of life-table data and demographic methods, including key-factor analysis, are described.