A new research has suggested that urban light pollution attracts migrating birds as they birds in Northern Hemisphere travel southward during fall each year.
The latest research paper was published in earlier this month in the journal Ecology Letters. In order to find migrating birds’ habit, Jeff Buler, an ecologist at the University of Delaware and his colleagues created a map with density of birds in city environment.
In a news release, Buler wrote, “Shortly after sunset, at around civil twilight, they all take off in these well-synchronized flights that show up as a sudden bloom of reflectivity on the radar. We take a snapshot of that, which allows us to map out where they were on the ground and at what densities. It basically gives us a picture of their distributions on the ground.”
“We think artificial light might be a mechanism of attraction because we know at a very small scale, birds are attracted to light. Much like insects are drawn to a streetlight at night, birds are also drawn to places like lighthouses. Especially when visibility is poor, you can get these big fall-outs at lighthouses and sports complexes. Stadiums will have birds land in the stadium if it’s foggy at night and the lights are on.”
“We estimate that these flying birds can see a city on the horizon up to several hundred kilometers away. Essentially, there is no place in the northeastern United States where they can’t see the sky glow of a city.”
“Domestic cats could be the largest anthropogenic source of mortality for birds. If birds are being drawn into these heavily developed areas, it may be increasing their risk of mortality from anthropogenic sources and it may also be that the resources in those habitats are going to be depleted much faster because of competition with other birds.”
“If you think about it from an evolutionary sense, for all wildlife really, mammals and insects and birds, they’ve only been exposed to this light pollution for less than 200 years. They’re still adapting to the light.”