Monarch butterflies were migrating in great numbers along the Cobourg waterfront, traveling from east to west. While stationed on the pier, we counted 95 in five minutes which was a conservative estimate since we weren't observing the entire waterfront band along which the migration took place. I think it would be safe to say that the actual numbers for the morning were in the thousands!
(Photographed September 25, 2017 at Cobourg Beach, Pier & Waterfront Trail, Cobourg, Ontario, Canada)