Wall threatens rich wildlife along US-Mexican border

By Andrea Barthelemy — The sheer diversity of wildlife along the border between the United States and Mexico is immense, taking in species like the California red-legged frog, which is protected under US law, and the rare Jaguarundi wild cat. The south-eastern tip of Texas, along the Rio Grande valley, is home to a wider diversity of wildlife than other regions of North America. There are more than 700 vertebrate species in the Lower Rio Grande Valley National Wildlife Refuge, one of three conservation areas stretching along the eastern part of the border to the Gulf of Mexico.
Since 2009 a massive border fence provided with only narrow passages has cut through large parts of the reserve.
Now, a broad strip has been cleared on both sides of the fence, which is illuminated at night in some sections. Conservationists have long complained about the barrier’s impact on wildlife.
They say the passages are too narrow for the larger animals, such as bighorn sheep and pumas, and that the cleared strips form a barrier to smaller animals unwilling to leave the protection afforded by vegetation.
About 1,200 kilometres of the border, measuring a total of 3,144 kilometres in length, is already marked by fences.
“Not surprisingly, the threats to these species are exacerbated by the fact that the ecosystems in this region are split by a political boundary that greatly complicates conservation efforts,” says Rick van Schoik of the San Diego State University in California.
Even bird species are affected, such as the burrowing owl, which spends most of its time on the ground and has difficulty flying over the barrier, according to Van Schoik.
The last ocelots living wild in the US inhabit the Rio Grande region. There are around 50 of these small leopard-like cats to the north of the border, their route to the larger and genetically more diverse population to the south blocked.
Cougars and jaguars are also restricted by the fence already in place.
In 2011 a team from the University of Texas researched the effects of the partial barrier on wildlife, which includes four species seen as endangered, either globally or in the US and Mexico and a further 23 species with small range sizes.
Outside Magazine has tried to calculate with the aid of a programme created by the US Fish and Wildlife Service on endangered species what a total wall would mean for wildlife in the area.
The outcome: the wall will “potentially impact 111 endangered species, 108 species of migratory bird, four wildlife refuges and fish hatcheries, and an unknown number of protected wetlands.” — DPA