Light pollution has a significant impact on wildlife.  Nighttime light can disrupt the migration of many birds.  Most songbirds migrate at night.  Excessive nighttime light can disorient them altering their path and even causing an increase in building collisions.  

There was a day when you could look at the night sky and see it lit up with stars with the bright streak of the Milky Way across the sky.  Now in Groton only the brightest stars are visible.  There was a day when kids could collect a jar of fireflies.  Now they are not that common.

Light pollution is a significant but overlooked driver of the rapid decline of insect populations.  Nighttime lights can lure moths to their death around light bulbs, and disrupt the signals of fireflies. Many nighttime-blooming plants are pollinated by our nocturnal moths.

A few simple choices can greatly lessen the impact of outdoor lighting. https://www.grotongardenclub.org/post/light-pollution-garden