In this book, I have shown that suboptimal wind speeds, updrafts, and turbulence reduce the ability of olfactory predators to locate prey, and that these atmospheric conditions are predictable in both time and space. In this and the following chapters, I examine whether nesting birds take advantage of these atmospheric conditions by locating their nests in areas where these conditions occur and whether those birds that do so experience a lower risk of predation from olfactory predators than birds that hide elsewhere. Evolutionary forces should favor birds that can nest in safe locations because predation is responsible for most (80%) nest failures (Martin 1993; Chalfoun et al. 2002a; Chalfoun et al. 2002b).