Washington Department of Fish and Wildlife Portland, Oregon
Biologists designing recovery strategies for at-risk butterflies have long recognized that healthy butterfly populations have a metapopulation structure which supports population persistence. This includes sufficient high quality habitat within patches, and patches that are large enough and close enough together to support movement between the patches. Movement between patches is critical because it is not uncommon for butterfly patches to occasionally go extinct when conditions are inhospitable due to external factors (e.g. drought or fire) or internal factors (e.g. density-dependent herbivory decimated the hostplant populations). As long as patches are within a butterfly’s dispersal distance and there are sufficient dispersers in the landscape, the patches can be recolonized. To understand endangered Taylor’s checkerspot butterfly (Euphydryas editha taylori)dispersal and movement, we mapped flight paths of female butterflies in both high quality and degraded habitat. As expected, butterflies moved more slowly in high quality habitat (average time per move 4 minutes and move length 5m) than in degraded grassland (average time per move 0.8 minutes and move length 35m). These movement paramters translate to very different lifetime dispersal distances in the two habitat types. With this information in hand, we aim to design landscape restoration strategies that facilitate metapopulation persistence of this endangered butterfly.
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