Population variability
For all three groups, we found a significant negative relationship between the log-transformed detrended variability in population change and years to extinction (Table 2; Fig. 2), showing that year-to-year population variability does indeed increase as extinction is approached. In relation to body size, all our models suggest that the magnitude of annual population variability is higher as body size decreases (Table 2; Fig. 2). An interaction between body size and years to extinction was included in the best fitting models, or those within two AIC units thereof (Table 2). This interaction was significant and negative in the non-avian subset (Table 2), suggesting a greater increase in variability in larger-bodied taxa.