Figure 1.

Map of study locations in Northern California, USA. Fifty butterfly species occurring at these locations were ranked by average population volatility. Inset are interannual time series showing the variation in population dynamics encompassed by these species. (a) Vanessa cardui was ranked the most volatile species, (b) Brephidium exile, the tenth most volatile, and (c) Pieris rapae, the 49th most volatile. Time series constructed using count data from the five low-elevation sites. Illustrations: M.L.F.