CONTRAST IN POPULATION DYNAMICS
FIGURE 3.13 The population of mountain gorillas on the Virunga Volcanoes has varied by 200, from a low of 250 to a high of 450 individuals. Meanwhile, the number of Bay checkerspot butterflies on Jasper Ridge varied by nearly 5,000, from 80 to 5,000 between 1960 and 1997, when it became locally extinct. (Data from Labine 1968, Robbins et al. 2006)