Analysis of the standing age distribution and age-specific recruitment rate of the George River and Beverly barren-ground caribou populations

Abstract

The primary advantage of the standing age distribution of a population is that it can be sampled. Analysis of the age frequencies for estimates of survival rates and determinations of population status by life table construction depend heavily on assumption that require additional data to evaluate. The analysis of age structures for the George River (Messier et al., 1988) and Beverly (Thomas and Barry, 1990a,b) caribou herd was reviewed. An alternativ method of estimating age specific survival rates was explored. The dependence of the life tables produced by the analysis of Messier et al. (1988) and Thomas and Barry (1990a,b) on tenuous and untestable assumptions regarding population growth rate over the life span of the oldest animals, stability of the standing age distribution, and constancy of life table parameters was emphasized. Although the life tables produced by Messier et al. (1988) for the George River herd and Thomas and Barry (1990a,b) for the Beverly herd are probably the best available for barren-ground caribou, they should be used with caution, particularly for management decisions.