Covariations between life-history traits
Individuals with longer generation times started reproducing later, lived longer and produced fewer recruits per breeding season compared to individuals with shorter generation times (Figure 1A-C, Table 2). In addition, individuals with longer generation times had higher lifetime reproductive success, but not necessarily higher individual growth rates (Figure 1D and E, Table 2). This is partly explained by individual growth rate being a metric that puts more weight on reproduction earlier in life (McGraw & Caswell 1996). Consequently, we found that individuals with the same lifespan could have quite different generation times, with different individuals reproducing much earlier or later relative to their lifespan (Figure 1B). There was a negative covariance between lifespan and reproductive rate, implying that individuals that lived longer were unlikely to produce many recruits per breeding attempt (Figure 1F). Individuals with greater lifetime reproductive success were those that lived longer, produced more recruits per breeding attempt, had longer generation times and had higher expected individual growth rates (Table 2).