In his final months in office, Donald Trump has ramped up construction on his promised physical border between the US and Mexico – devastating wildlife habitats and increasing the migrant death toll

At Sierra Vista Ranch in Arizona near the Mexican border, Troy McDaniel is warming up his helicopter. McDaniel, tall and slim in a tan jumpsuit, began taking flying lessons in the 80s, and has since logged 2,000 miles in the air. The helicopter, a cosy, two-seater Robinson R22 Alpha is considered a work vehicle and used to monitor the 640-acre ranch, but it’s clear he relishes any opportunity to fly. “We will have no fun at all,” he deadpans.

McDaniel and his wife, Melissa Owen, bought their ranch and the 100-year-old adobe house that came with it in 2003. Years before, Owen began volunteering at the nearby Buenos Aires National Wildlife Refuge, and fell in love with the beauty and natural diversity of the area, as well as the quiet of their tiny town. That all changed last July when construction vehicles and large machinery started “barrelling down the two-lane state road”, says Owen.