The intrinsic rate of natural increase and reproductive effort in primates

Abstract

The intrinsic rate of natural increase (rmax) is calculated for 58 primate species. It is found that this parameter is negatively correlated with body weight, so that larger primate species consistently have a lower rmax than do smaller species. Although there is no apparent link between the raw value of rmax and environmental predictability, a relationship between a high rmax, relative to body weight, and an unpredictable environment is found to exist. However, there is no relationship between a predictable environment and either the raw value of rmax, or the relative rmax. After body size effects are removed, rmax is not correlated with basal metabolic rate (BMR). Pre‐natal maternal investment (MI) is found to correlate highly with BMR, even after the removal of body weight effects. MI does not correlate either with rmax or with environmental predictability. Diet appears to have little influence either on rmax on MI, but there is some indication that folivores have both a high relative rmax and a high relative MI. These results are discussed in the light of theories of life‐history strategy evolution.