Male harassment alters movement patterns and decreases meta-population stability in checkerspot butterflies
Results/Conclusions: We found strong differences in the rates of harassment between E. phaeton and E. e. taylori. E. phaeton females experienced little or no harassment while E. e. taylori females often experienced unrelenting harassment by courting males. Female movement patterns were strongly affected by harassing males, and often attempted to hide or flee. Fleeing females were frequently chased out of suitable habitat patches. In E. e. taylori, fleeing movements caused the overall step-length pattern to be best fit by a bounded power-law as compared to an exponential distribution, while an exponential best fit the step-lengths of the largely unharassed E. phaetonfemales. When compared against a broader set of distributions, both Weibull and and mixtures of exponential distributions were favored in both species. Meta-population models revealed that, when populations become isolated, intense male harassment increases extinction probability. Models incorporating male harassment indicated a long-term extinction probability of 17.5 to 61%, depending upon population size, compared 1.2 to 27% for the same population sizes using a typical density-depend emigration function.