The Age-Stage, Two-Sex Life Table with an Offspring Sex Ratio Dependent on Female Age

Abstract

In the age-stage, two-sex life table, both sexes and variable developmental rates are incorporated into life table theory. However, in many species, the sex ratio of the offspring depends on the age of the female. Thus, the sex ratio based on the pooled total fecundity of a single cohort may lead to an over- or underestimation of population parameters and consequently to errors in simulation. This paper describes a new theoretical approach in which the female age dependence of the offspring sex ratio is recognized. The population parameters (the intrinsic rate of increase, the net reproductive rate, and the mean generation time) and the sex ratio of a population with a stable age structure can be calculated with this new theory.