FIG. 46.7 Density-independent effects on population size. Independent of population density, extreme weather (such as drought) lowers the quality of habitat for Song Sparrows, reducing the number of territories occupied. Source: Data from M. K. Chase, N. Nur, and G. R. Geupel, 2005, “Effects of Weather and Population Density on Reproductive Success and Population Dynamics in a Song Sparrow (Melospiza melodia) Population: A Long-Term Study,” The Auk 122(2):571–592.