Birth, Death, and Chance
of Elephant Populations
The dynamics of elephant populations hold great theoretical and practical interest. The elephant shares many demographic traits with humans—age of sexual maturity, long gestation, single offspring, low death date, and high longevity. It is not only the statistical details of elephant demography, but also the evolution of life history traits and population regulation in this large mammal that are of considerable interest. From a practical viewpoint, an adequate understanding of demographic processes in elephant populations is essential to making sound conservation judgments. Whether it is comprehending how density influences demography or how populations respond to the pressures of poaching, a fundamental consideration in conservation is the trajectory of animal numbers.
Understanding the dynamics of populations requires not only good empirical data from the field, but also the backing of robust mathematical models. Often, very subjective assessments are made about the dynamics of a population. I have, for instance, commonly heard statements to the effect that, “Every elephant group has a calf and thus the population must be doing very well. ” This could be correct, or it could be completely wrong. The mere presence of a calf in every group does not by itself say anything about the trends in a population. If the population is suffering a high death rate, it could be declining. “Rule-of-thumb” assessments sometimes can be made about the dynamics of a population based on fragmentary data, but this requires additional knowl-