Conservationists say they are concerned about stadium lights being built along the U.S.-Mexico border in places known for their dark skies, and one nonprofit says the lights could be harmful to southern Arizona wildlife.
The lights have not been turned on in rural areas, and in some places have not even been wired.
But researchers say that although bright lights can help humans navigate at night, they can have the opposite effect on nocturnal animals.
They can also cause what dark sky advocates call light pollution, which makes it difficult to see the stars.
"The concern that we have about the lighting, is that it’s going into very remote areas, some of which are close to conservation areas along the border," said John Barentine, of Dark Sky International.
He says studies show that excessive light at night can also harm plants.
