Butterfly abundance along an urban gradient in Montréal, Quebec, Canada

This dataset consists of field data collected from 44 open sites located around Montréal, Quebec, Canada that were visited in rotation from May to August in 2017 or 2018. During each visit to a site, two observers walked a designated 300 m transect and collected data on the identity and abundance of all butterflies observed. Field data was analyzed to show that urban butterfly communities were dominated by a few, highly abundant, non-native species. The data also showed that for most of the butterfly community, species with longer flight periods were more common in urban areas. Finally, the data showed that urban butterfly communities tended to be more homogenized than rural communities at both the taxonomic and functional levels.