One of the many warblers passing through Rondeau this migration.
The American Redstart singing his heart out.
Like the Painted Redstart and other “redstarts” of the Neotropics, the American Redstart flashes the bright patches in its tail and wings. This seems to startle insect prey and give the birds an opportunity to catch them. Though these birds share a common name, they are not closely related to each other.
source - Cornell Lab of Ornithology.