Traits and habitat specialization influence in future range shifts of butterflies in a warmer climate

Sammanfattning: Climate change is considered one of the greatest future threats against biodiversity. One predicted consequence of a global temperature increase is that biomes will move against the poles, which will force species to either adapt to an unsuitable habitat or follow their climatic range shift. A common way to assess the future geographical distribution of a species is to predict their future climatic range. However, this excludes factors that could interfere with the species ability to follow their range shift, such as dispersal ability. The importance of expansion-related traits are often assumed rather than quantified. This study investigated if the specialist butterfly Pyrgus armoricanus, living at its northern range limit in south Sweden, will be able to expand north as the temperature increases. The study also explored the importance of six traits on a butterfly’s range shift ability; habitat specialization, growth rate, emigration probability, establishment probability, dispersal vagrancy and dispersal probability. The study found that the butterfly Pyrgus armoricanus will not be able to expand north in Sweden due to low dispersal ability and habitat availability. The most important traits for a butterfly’s ability to expand north in Sweden was growth rate, dispersal ability and habitat generalisation. Specialized butterflies dependent on well managed meadows will have limited success in following their northern range limit, and restoration is necessary to avoid future biodiversity degradation.