Density-dependent regulation of natural and laboratory rotifer populations

Density-dependent regulation of abundance is fundamentally important in the dynamics of most animal populations. Density effects, however, have rarely been quantified in natural populations, so population models typically have a large uncertainty in their predictions. We used models generated from time series analysis to explore the form and strength of density-dependence in several natural rotifer populations. Population growth rate (r) decreased linearly or non-linearly with increased population density, depending on the rotifer species. Density effects in natural populations reduced r to 0 at densities of 1–101−1 for 8 of the 9 rotifer species investigated. The sensitivities of these spe…