This is intended to be a comprehensive list of all publicly available groups for reporting, discussion and identification of Ontario's natural history. I have also included some groups focused on the Great Lakes region or Northeastern North America.
Be sure to read and follow all rules and instructions provided for each group. In particular, note that some of these are intended for sharing of notable sightings, and not necessarily for discussion, identification or other purposes. Please let me know of any additions or corrections, as I want this list to be accurate and comprehensive.
Field Naturalists of Ontario Facebook: General discussion of Ontario nature. A wonderful place to learn!
Muskoka Bird Board: Despite the name, a board for general nature sightings in Muskoka and nearby areas
Simcoe Nature Board: Simcoe County. Birds and general nature sightings.
Ontbirds: The ultimate listserv for rare birds across Ontario
Ontario Birds Facebook:
This huge and growing group is increasingly unwieldy to get any useful
information out of, but a lot of interesting stuff pops up
Toronto and Southern Ontario Birding: A large forum for birding and general nature in the GTA and across Ontario
NWOBirds: Northwestern Ontario bird reports. Many rare birds show up here but not on Ontbirds. You must request membership to view or post
Guelph/Cambridge/KW Birding Forum: A very underutilized forum.
Wellbirds: Birds in Guelph and Wellington County. The only way to view posts is by requesting to receive the emails
Waterloo Region Birds Facebook: Rarities and discussion in Waterloo Region
Brantbirds: Birds in Brant County
Hamiltonbirds: A very well-used group for notable birds in the Hamilton Study Area, a large area extending out to Mississauga, Guelph, Cambridge and well into Niagara Region
WEPBirds: Birds in Essex County including Pelee and Windsor
ABA Great Lakes News and Discussion Facebook: A great idea that has seen very limited use. If it ever takes off this group would be very interesting
Ontario Butterflies: Butterflies across Ontario, primarily used for reporting rare species
OntOdes: Dragonflies and damselflies across Ontario, primarily used for reporting rare species
Hamilton Butterflies and Dragonflies Google Group: Sightings in the Hamilton Study Area (roughly Mississauga to Guelph to Brantford to Grimsby)
Ontario Insects and Arachnids Facebook: Exactly what you'd expect
Northeast Odonata Facebook: An incredible group for anyone with an interest in dragonflies and damselflies. Perhaps the friendliest group I've seen online
Great Lakes Odonata: A discussion group that seems to have been mostly supplanted by Northeast Odonata on Facebook
Ontario Reptile and Amphibian Atlas Facebook: A large group for general discussion. Like Ontario Birds, I feel that this group is a bit too large for useful discussion, but still worth checking out
Field Botanists of Ontario Facebook: An excellent botany discussion group