Proposals in the U.S. Congress to build hundreds of miles of walls along the U.S.-Mexican border have added fuel to ongoing debate in the United States about how best to control illegal immigration. Largely ignored, however, is the question of how border walls would affect wildlife and ecosystems. Green groups warn the impact could be significant. “Current policies and activities already have major localized impacts on the species and ecosystems by the border,” says Oscar Moctezuma, executive director of Naturalia, a Mexican group that manages private conservation ranches on the border. “But the construction of so many walls would broaden that impact considerably.” A proposal calling for 700 miles (1,100 kms) of border walls forms part of an immigration bill approved in December by... [Log in to read more]