Time series generated with the model where, (a) for the first 40 generations (before vertical red line), when both viability selection and delayed density effects on survival during the non-breeding season and fecundity were operating and, for the last 20 generations, only the effects of current population size on fecundity and survival were modelled (i.e. no viability selection and no delayed density effects); (b) population size excluding the effects of viability selection (only the effects of delayed density dependence on fecundity and survival were operating) or (c) excluding the effects of delayed density dependence (only the effects of viability selection were operating). In (d), times series were generated as in (a) but with low heritability (see Results for details). In (b), population crashed (i.e. population size <1) at generation 10. In both (b) and (c), the model incorporated the effects of current abundance on fecundity and survival and heritability for body size. In (a) and (d) inset figures represent autocorrelograms for population size obtained from the mathematical model including delayed density dependence, viability and fecundity selection (before red line) or without both delayed density dependence and viability selection (after red line). See Material and methods for details and model parameters.