Every year in North America, between 3.5 and 4.0 billion birds take part in migrations of thousands of miles. More than 80% of them travel at night, navigating with the night sky.
Artificial lights can attract and disorient birds resulting in an inability to navigate to their destination expend already limited energy resources. The exhaustion can leave them vulnerable to threats, including predators, collisions with buildings, and inability to find food.
Fortunately, the simple action of shielding or turning off lights can help birds navigate.
It is particularly important to take these measures as early in the evening as possible, as migrants begin their nocturnal migrations at dusk, during spring and fall migration periods. In addition to helping birds, these efforts have the additional benefits of reducing energy usage and saving money.
There are two simple actions people can take to have a big impact on birds:
- Shield outdoor lights to prevent light from being emitted upwards.
- Turn off lights before midnight during bird migration seasons (April-May and August-September).