massive movement of songbirds on Monday, May

Please see the numbers from Monday at the Tadoussac Bird Observatory in Quebec, Canada.

Observatoire d’Oiseaux de Tadoussac - Dunes, La Haute-Côte-Nord County, Quebec

Over 720,000 warblers, and many other birds. 

The detailed report is in this linked eBird checklist.

https://ebird.org/view/checklist/S46116491
The work of bird observatories worldwide demonstrates the capability of skilled observers, and the value of these programs. It also shows the value of eBird to capture and report data.