Intrinsic rate of increase (r) calculated for populations of species that differ greatly in their potential for the rate of population growth

Intrinsic rate of increase (r)* calculated for populations of species that differ greatly in their potential for the rate of population growth

species intrinsic rate of increase (r)

elephant seal 0.091

ring-necked pheasant 1.02

field vole 3.18

flour beetle 23

water flea 69

*Values above zero indicate that the population is increasing. The higher the value of r, the faster the intrinsic growth rate of the population. Source: Adapted from Robert E. Ricklefs, The Economy of Nature, 3rd edition, copyright © 1993 by W.H. Freeman & Company, used with permission.