[A flock of birds flies past the Gateway Arch – Photo Credit: Jeff Roberson/AP]
St. Louis on the Bird Migration Route
Many species of animals migrate during the fall and spring seasons, but one of the most prominent migrations in North America is that of birds and butterflies. Seeking a better climate, seasonal food sources, and greater opportunities for breeding, thousands of birds and butterflies migrate from the northern regions of the United States and Canada down to Mexico each year.
The proximity of the Mississippi River makes the St. Louis region a critical point in the migration route, as the Mississippi Flyway is used by 300+ bird species and thousands of birds traveling from Canada to the southern United States each year.
Organizations like the National Audubon Society are dedicated to protecting birds and the places they need, especially when they are most vulnerable during the migration seasons. Some chapters have created programs such as “Lights Out for Birds”, which sends alerts to business and homeowners during peak migration so they can turn off their lights for the night as to not disorient the birds.
Bird Migrations Impacted by Urban Lights
As the use of exterior beams to lit up iconic buildings at night has increased during the past decades, their effects on birds have become more apparent. Bright lights can often disorient birds who fly into the light beams, sometimes causing collisions with the buildings and in worst cases for the bird to get trapped in the light beams.
During the migration season, these effects can take a particular toll on birds. The long distances the birds must travel across the country cause them to lose up to 20-30% of their body weight, putting the animal in a vulnerable position. For birds such as songbirds and waterfowl species, who primarily migrate at night to potentially avoid predators, this vulnerability means that any disorientation or stress they suffer from building lights may have serious side effects.
Even lights as small as those on the outside of homes can affect birds and by shutting them off during peak migration times, homeowners can help ensure safer travels for birds. The Cornell Lab of Ornithology has developed BirdCast, an online platform that provides real-time predictions of bird migrations. Check it out to figure out when shutting off your lights will be most helpful to bird migration!
Gateway Arch Efforts to Reduce Light Pollution
In an effort spearheaded by the National Park Service and the Audubon Society, the Gateway Arch did not use lights to illuminate the monument at night from September 17th through the 30th, and will continue this effort during peak migration periods to ensure a healthy and safe migration for North American birds.
The Gateway Arch began temporarily shutting off its lights starting in 2001 when the lights were originally installed on the monument. With the renovation and reopening of the Gateway Arch in August of 2018, 26 xenon skylights outfitted with custom lenses replaced the 44 original light fixtures. These high tech lights have a laser-like focus on the Arch, intended to limit both the light beams’ scope and the birds’ interactions with the beams.
Article Source: “Lights Out” for the Arch to protect migrating birds.
This article was written by Mikaela Gatewood, Communication Associate at the Office of Sustainability.