Abstract
The intrinsic rate of natural increase (r m) is calculated for 72 primate species, using Cole's (1954) equation. The value of r m relative to body mass is then calculated by use of allometric analysis. Both r mand relative r m are used to test the prediction that animals in unpredictable and/or harsh habitats will have a higher r mthan will those in more predictable and/or less harsh habitats. No significant link between habitat type and r mis found. However, correlations between ecology and relative r msuggest that relative r mis high in primate species living in more open habitats and low in species found in primary rainforest. Although there are few correlations between relative r m and climate parameters, those that are found suggest that variable climates, dry climates and hot climates will select for a high relative r m.