Butterflies are extremely rapid range shifters under global warming climate conditions. Unfortunately, for many species, especially for specialized species and those from mountainous areas, there are not enough areas to shift to. For other species, however, completely new areas can become suitable habitat. Hence, butterflies represent a mixed group of winners and losers in areas affected by climate change.
Interestingly, Camille Parmesan showed in her research that butterflies do not only change their range of occurrence, but also change their built-in migratory behavior. At the butterfly symposium she gave an example of Euphydras editha, which is an endangered species in America and a species one would consider a classical loser. One of its subspecies, Euphydryas editha quino, declined drastically due to climate change and habitat loss, from thousands over thousands of individuals that have been observed in the 1940s to two remaining population nowadays. Ongoing human construction activities, air pollution and fire events led to the assumption that this species is effectively extinct, and assisted migration has not even been considered due to lack of suitable habitat containing the host plant of the species, Plantago erecta.
Surprisingly, a few years after this sad cognition, new populations of species could be found in locations at higher altitudes in areas where its host plant was not present. The Quino checkerspot butterfly did not only manage to extend its occurrence range upwards, but also shifted its diet onto a different host plant, Collinsia parviflora. And even more exciting, this shift is associated with genetic changes in the butterfly.
This is a very positive example for rapid evolutionary changes in invertebrates, and a representation of how quickly they are able to inherent traits to become an integral part of new ecosystems. However, this showpiece was only possible because the butterfly was able to disperse to new “quasi-habitats”. Unfortunately, we must to counteract the massive pressure of anthropogenic development to provide enough corridors and areas for wildlife to disperse to allow them adapting to the changing conditions. This is presumably not new to any of you, but I think it shows again how important it is to consider not only one species or one habitat in conservation management, but also allow space for the dynamics in nature.