What is a Monarch roost?

In the late summer, monarchs in Ontario begin their 3000 km journey south to Mexico. Unlike the spring migration north, the fall migration is undertaken by a single generation of butterflies.

Monarchs are diurnal migrants, meaning they migrate during the day. At night, migratory monarchs roost on trees or shrubs and often form large groups of butterflies. These roosts are usually near meadows or other habitat that provides good foraging opportunities for the monarchs so they can feed and gain the energy required to complete their migration.

Based on our current knowledge of monarch roosts in Ontario, roosts are typically found in proximity to the Great Lakes but they can be found anywhere with suitable habitat in southern and eastern Ontario. Locations such as Point Pelee on Lake Erie and Presqu’ile on Lake Ontario are good places to spot monarch roosts.

The best times to look for roosts are evenings and early mornings. Monarch roosts can be a single individual to many hundreds or thousands of individuals.

Posted by vincef vincef, September 13, 2021 14:22


Hello! Happy to see this project. Just comes to mind when talking "roosts". Recall on our Apartment property-22 Acres, top of Bayview Extension. Our now absent Red Oak tree was a roost tree for many Sept.-Octobers! Back in 1992-1999? Recall sseeing hundreds of Monarch's on west side in late day sunshine! So amazing never forget!!! annem4g

Posted by annem4g about 1 year ago (Flag)

Hello, I would love to add to iNaturalist but I find Monarchs very hard to photograph, they flit about so much. So I hope you will record my sighting of today, 19 Sep 2021, at Pinery Provincial Park, on the edge of the lake, adjacent to parking area 9, around 11:30AM. I saw 2 different monarchs flying in a southwesterly direction, off the beach and into the mixed oak and pine savannah of the park.
Hope this little bit help you tracking.

Posted by elmslie about 1 year ago (Flag)

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