Inter- and intra-specific differences in butterfly behaviour at boundaries
- To plan effective conservation measures and to predict which species will be able to change distribution in response to climate change, there is an increasing need for understanding species dispersal abilities and how species move in complex landscapes. Responses to habitat boundaries affect emigration rates from habitat and are therefore important determinants of species dispersal. There are, however, few studies linking dispersal parameters to likelihood of crossing barriers across several species.
- In this study, dispersal and likelihood of crossing boundaries, which are presented here as tall and dense tree plantation, were investigated for seven butterfly species. Effects of adult age and sex on the dispersal and behaviour at boundaries were also analysed.
- Our results demonstrate differences in movements and response to habitat boundaries between species belonging to different butterfly families. Pieridae species were the most likely to cross boundaries and most mobile, whilst with the Lycaenidae species only a small fraction of individuals crossed the tall dense boundary.
- Individuals and species that moved with longer move bouts (i.e. steps) were more likely to cross boundaries. Therefore, we propose using step length, which is relatively easy to measure, as a proxy for butterfly dispersal at the landscape level.
- Female butterflies moved less than males within habitat but crossed boundaries more often than males, indicating that dispersal data needs to be collected for the two sexes separately to provide more accurate estimates of species ability to colonise new areas.