When a movement to turn off lights late at night got its start in Chicago in 2003, many building owners agreed to do so from 11 p.m. to dawn during the five months in spring and fall in which birds migrate. Doing so has saved the lives of thousands of migratory birds.
2003 年美國芝加哥發起「深夜熄燈運動」，不少建築大樓業主都同意在候鳥遷徙的春秋 5 個月間，晚上 11 點到黎明前關掉夜間照明，也挽救了上萬隻候鳥的生命。