Wall of the wild: animals on the US-Mexico border – in pictures

There are already more than 650 miles of infrastructure along the border between Mexico and the US, including this section at Tijuana. These walls and fences cut through fragile ecosystems, separating areas populated by more than 1,500 plants and animal species, 93 of them listed by the International Union for Conservation of Nature (IUCN) as critically endangered, endangered or vulnerable.