Experimental Density-Related Emigration in the Cranberry Fritillary Boloria aquilonaris
- Cite this article as:
- Brunzel, S. Journal of Insect Behavior (2002) 15: 739. doi:10.1023/A:1021167205560
Studies on sedentary butterflies often show that most individuals cover only short distances and rarely leave their original patch. An important question for metapopulation dynamics and conservation is “When and why do sedentary species disperse?” To imitate high population densities I harassed individuals of the sedentary butterfly Boloria aquilonaris with a dummy and recorded the time that passed until they emigrated from their original bogpatch of 800 m2. Harassed individuals emigrated significantly sooner than unharassed ones. Repeated harassment following their return to the marked patch led to an increase in the residence times of these individuals outside the patch. Individuals receiving a potentially detrimental stimulus (e.g., harassment) are more likely to emigrate sooner than other individuals. The results support the hypothesis that emigration is density dependent in this butterfly, such that gene flow and colonization may be episodic.