About the Ontario Butterfly Atlas

..maps...display of records...flight season charts


The Ontario Butterfly Atlas is a project of the Toronto Entomologists' Association. The TEA has been accumulating records and publishing annual seasonal summaries (Ontario Lepidoptera) for 50 years, with the first edition appearing in 1969. The first maps appeared in the TEA's Ontario Butterfly Atlas book, published in 1991. The present interactive web-based maps started in 2011. Since that time, the database of records supporting the maps has grown from 65,000 in 2011 to 390,000 today. The latest update was in March 2019.


This atlas is to replace the TEA's original online atlas, the Advanced Atlas, which had one page for the menus and a separate page for the maps. The new atlas also replaces the Basic Atlas (menus and maps on the same page) that was introduced in 2017 with support from Ontario Nature. Both of those atlases were based on the Google Fusion Tables software, which Google is terminating in December 2019. This new atlas will incorporate all of the functionality of both previous atlases.


Atlas data comes from eButterfly records, iNaturalist records, BAMONA records, and records submitted directly to the TEA. Some data is from other sources (e.g., ROM, other museums, BOLD). Data from all TEA seasonal summaries is included. The atlas is updated at least once a year.


We thank Bird Studies Canada for providing the shape files defining the 10,747 10 km squares shown on these maps. The shape files for counties and parks are from Ontario's Land Information Office and contain information licenced under the Open Government Licence - Ontario.


Other Canadian butterfly atlases: the Maritimes Butterfly Atlas (see their maps here) and the TEA's Prairie Provinces Butterfly Atlas. See also the TEA's Ontario Moth Atlas.



There will be inevitably be some errors or questionable observations, and we would like to know about this. We also welcome any questions about the atlas or suggestions for improving it. Contact the TEA (Alan Macnaughton, info@ontarioinsects.org).


In publications or other research use of this data, use the following citation: Alan Macnaughton, Ross Layberry, Rick Cavasin, Bev Edwards and Colin Jones. Ontario Butterfly Atlas (Supply date accessed here).