Years to extinction
In agreement with the first hypothesis, models with a log-transformed
population size significantly outperformed those fit with non-logged
population size (Δ AIC > 2) for data on all species
combined, only birds and only non-avian species (Table S2). Also, in all
three groups of data a positive interaction between body size and
population size was included in a model within two AIC units of the best
fitting model (Table 2); these models suggest that populations of
smaller-bodied species are under imminent risk of extinction over a
larger range of population size.