FIGURE 2-22 Deviations from the 50-year mean (1951-2000) for quarterly (A) mean maximum and (B) mean minimum temperatures and quarterly precipitation at Rocky Ford, Colorado, weather station. Asterisks indicate deviations that are at least two standard deviations from the 50-year mean. The line shows quarterly trap success (number of individuals captured per 100 trap nights) for deer mice.

SOURCE: Reprinted with permission from Calisher et al. (2005a).

be zero was the wet, cold El Niño autumn of 1997 (Figures 2-22 and 2-23). Conversely, the highest juvenile recruitment was observed in the unusually wet summer of 1999. Because rainfall in the American southwest can be remarkably focal, and because we did not monitor for diseases or predation, we cannot determine with certainty exactly what caused these population declines and surges but the



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