More than 1,000 species of animals would face serious threats to their survival if U.S. President Donald Trump's proposed border wall with Mexico is built, scientists warned on Tuesday.
Iconic creatures such as the Peninsular Bighorn sheep, Mexican gray wolf and the Sonoran pronghorn antelope — all of which are already endangered -- would see their populations dangerously fragmented by a wall, said the letter published in the journal BioScience.
Jaguars (panthera onca) and ocelots (leopardus pardalis) would be among the species that would have "residual U.S. populations" covering 20,000 square kilometers or less, raising their risk of dying off completely in the United States.
More than 2,700 global scientists signed on to the letter by lead author Robert Peters of Defenders of Wildlife, a conservation group. The letter details threats to biodiversity along the 3,200-kilometer U.S.-Mexico border, which Trump wants to wall off in an effort to stop the flow of illegal migrants.
"Fence and wall construction over the past decade and efforts by the Trump administration to complete a continuous border 'wall' threaten some of the continent's most biologically diverse regions," said the letter. "Already-built sections of the wall are reducing the area, quality, and connectivity of plant and animal habitats and are compromising more than a century of binational investment in conservation," it added, lamenting that "political and media attention... often understate or misrepresent the harm done to biodiversity."
When populations of animals are fragmented, they have a harder time finding mates, food, water and safe habitat, and face higher risks of extinction.
"Cut off like this, the bighorn and other animals and plants will become zombie species -- populations that are demographically and genetically doomed," said co-author and Stanford University biologist Rodolfo Dirzo.
Co-author and Stanford University professor of biology Paul Ehrlich said in a statement that the wall, and "the accompanying construction and maintenance infrastructure would be a crime against biodiversity."
The letter urged U.S. officials to identify species at risk from the wall construction, design barriers that allow wildlife to pass through as much as possible, and purchase or restore replacement habitat when environmental harm is inevitable.
As it stands, a U.S. law passed in 2005 gives the Department of Homeland Security authority to waive protections such as the Endangered Species Act if they are deemed to be factors in slowing the wall's construction.
Trump's wall has still not secured major financing. A bill that would have included US$25 billion to fund it failed last month in the House of Representatives.