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Ontario Butterfly Atlas Online
(317,000 records, updated August 2017 for records dated up to July 9, 2017)

Type any part of the species name,
or choose from the list
Select a Map Type
Select a Part of Ontario to View
Select which Records to Map
all 2017 only
Select which Data to Display through Colouring of Squares on Map
time trend of sightings
green historic and recent sightings
yellow recent sightings only
red historic sightings only

Recent is or after;
historic is before that time

year(s) of most recent record
green or later
yellow in between
red or before
year(s) of first record
green or later
yellow in between
red or before
number of records
green or more
yellow in between

Maps of Squares by Special Characteristics

Select a Map
no species
few species
many species
high effort by contributors
low effort by contributors
rare species and strays
species predicted by ROM Field Guide range maps
species predicted (as above) but not yet found

Select a Part of Ontario to View

Tables of Notable Observations
expect 20-second wait for results

Table of new county records (2017 and previous years)

Table of new birding-square records (2017 and previous years)

Table showing source of atlas records

Atlas Notes

(1) Submitting Records

Post records for inclusion in the Atlas on e-butterfly.org or iNaturalist.ca or, for large batches, email the TEA.

(2) Azures

Here are the rules currently (November 2016) being used in the atlas. This is all in flux because of the recent paper on azures.

  • Azure observations in counties in eastern and northern Ontario have been mapped as C. lucia (#109). For this purpose, eastern Ontario includes Frontenac and Renfrew counties and areas east of that -- which is basically Kingston and east. Northern counties include Muskoka, Haliburton and Nipissing and areas north of that. These are about 5,300 observations.
  • Azure observations elsewhere have been mapped by species only where Chris Schmidt has made an examination of that specific observation and determined the species. These observations include: C. lucia (#109), about 15 observations; C. neglecta (#110), 31 observations; and C. ladon (#108.1), 9 observations.
  • Other azure observations have been grouped, for now, into Azure sp. (#111). This has 5,890 observations.These are probably C. neglecta, but could be lucia or ladon.


(3) Other Notes
  • Try our new Ontario Silkmoth & Sphinx Moth Atlas. A butterfly atlas for the Prairie Provinces is under development. Also direct access Prairie 2
  • To zoom in or out on the large map, use the slider bar (top left of screen) or your mouse wheel. To see areas outside the screen (pan the map), click the directional arrows on the white circle (top left of screen) or click and drag with your mouse.
  • If the map type is 10 km squares and the map for any particular species is being displayed, click on a square to display a link to the underlying data for that square. If instead the species is "all species", clicking on a square will display a species list for this square.
  • The data includes is about half from eButterfly records and half from records submitted directly to the TEA. Data from all TEA seasonal summaries back to 1969 is included. Museum data back to 1867 is also included. However, only about 5% of Royal Ontario Museum records are included; this fraction will rise as databasing of ROM reocrds by volunteers continues.
  • 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.
  • Want more information about the maps? Click here for help in using the map and more details in how the maps were constructed.
  • Other Canadian butterfly atlases: Maritimes Butterfly Atlas (see their maps here)
  • There will be inevitably be some errors or questionable observations. We would like to know about this, or about any comments or questions you may have. Click here to email the developers.
  • In publications or other research use of this data, use the following citation: Alan Macnaughton, Ross Layberry, Colin Jones and Bev Edwards. Ontario Butterfly Atlas Online (Supply date accessed here).