Migratory songbirds face a gauntlet of human-created hazards on their twice-yearly journeys, and simple interventions can dramatically reduce mortality along migration routes.
The welfare of migratory birds depends on the entire length of their journey — threats at any point in the route affect individuals that may have successfully navigated thousands of miles. Communication tower lights, building glass, artificial lights, and pesticide applications along migration routes all take welfare tolls on individual birds completing extraordinary journeys. Coordinated Lights Out programs represent a rare welfare intervention where cities can save hundreds of thousands of birds with minimal cost and effort.