Safe Breeding Dates
While June certainly represents the peak month of breeding season for many Ontario birds, each species has a slightly different window during which breeding evidence may be displayed/observed. To complicate things, the timing can vary markedly between different parts of the province and migrants can still be moving through an area while local breeders have begun nesting.
To help atlassers and Regional Coordinators navigate this complexity, the Atlas has produced a series of seasonal charts depicting when a species may be breeding, when it may be migrating, and when it is safe to assume an observation of a species in breeding habitat is indeed a breeding individual. You can find these charts in chronological and in taxonomic order below.
For more information about safe breeding dates, including how to read the charts, please read Appendix H (Safe dates / breeding dates)
Last Updated: March 6, 2023