New species records for butterflies (Lepidoptera) on Herschel Island, Yukon, Canada, with notes on natural history

Abstract

AbstractComparisons of past and current butterfly species distributions are being used to gauge the effects of climatic change in various parts of the world. Historic butterfly records from Herschel Island, Yukon, Canada, presented an opportunity to do such a comparison in an Arctic tundra region known to have a diverse butterfly fauna. We compared historic species records (1916–1983) with newly collected ones (2007–2009) to assess possible changes in species distributions. Of the 21 species documented for Herschel Island, six were newly found and two were not reconfirmed. We postulate that warmer temperatures facilitated the apparent northerly range expansions of several species by making butterfly flight and dispersal possible. This is supported by interannual comparisons on a smaller time scale, 2007–2009. During this period, we observed accelerated butterfly phenology and higher relative abundance of butterflies associated with earlier snowmelt and with earlier and more intense early summer heating.