Those who wish to secure America's borders from ocelots, pronghorn antelopes, gray wolves, and bighorn sheep scored a victory earlier this month, as an amendment to a Homeland Security bill passed by the House mandates an additional 369 miles of fence that will prevent these animals from crossing the border.
The border wall, which was constructed after waiving three dozen federal environmental laws, is expected to be successful in reducing populations of these and other species, most of whom do not speak English or pay taxes. The science news site PhysOrg reports on a study for the peer-reviewed journal Conservation Biology, which found that Sonoran bighorn sheep populations north of the border rely on contact with those on the other side of the border to maintain genetic diversity.
A 2007 report in Salon found that habitat fragmentation was also reducing populations of ocelots – a rare species of wildcat that some argue could potentially steal jobs from Americans.
Indeed, the only large mammal whose migration is largely unaffected by the border wall are H. sapiens, whose opposable thumbs and developed neocortex enable them to simply use ladders or dig tunnels under the fence. Last year, the Federation of American Scientists reported that the US Border Patrol had discovered 93 cross-border tunnels since 1990.
What's more, almost half of illegal human immigrants avoided the border wall altogether by entering the US on a legal visa – an option not available to members of other species.
Still, by some measures, the border wall can be considered a success. Since its construction, there have been no reports of pronghorn antelopes enrolling in public schools, and the number of ocelots working in service industries appears to have been sharply reduced.
according to the Pew Hispanic Center, as many as 45 percent of undocumented foreigners in the United States didn't creep through the desert or float across the Rio Grande in an inner tube: they just overstayed their visas (the same thing done by at least six of the 9/11 hijackers).