Dirzo and Erhlich noted the border wall could also impede flying species that enjoy riding currents close to the ground. Examples include the endangered Quino checkerspot butterfly or the ferruginous pygmy owl.
Echoing those concerns, the National Audubon Society, the National Resources Defense Council, and more than 170 conservation groups penned a letter to Secretary of Homeland Security Kirstjen Nielsen in November.
The letter elaborated on the impact of a wall on “environmentally sensitive conservation areas” like the Lower Rio Grande Valley area, which has a plethora of butterfly and bird fauna. Bruce Stein, chief scientist at the National Wildlife Federation, wrote, “barriers like border walls can interfere with the ability of animals to meet their daily needs, make seasonal migrations or disperse to new areas.”
Quartz, which first reported on the letter to Nielsen, noted that an unfamiliar obstacle could even deter birds, despite the fact that they could theoretically fly to heights above it.