Biologists have been concerned that the border wall between the U.S. and Mexico would block the movement of wildlife between the two countries. That was the case for one Mexican wolf (Canis lupus baileyi), National Geographic reports. In late 2021, a wolf dubbed “Mr. Goodbar” set off across the Chihuahuan Desert in search of a mate when it encountered the 30-foot-high border wall. According to its GPS collar, the wolf spent nearly five days tracking along the wall before turning around and heading north.
U.S. Fish and Wildlife Service biologists had anticipated the wall would serve as a barrier and determined the endangered wolf population can recover without traveling back and forth to Mexico.