Endangered species affected by U.S. Mexico border wall

Photo courtesy of U.S. Fish and Wildlife Service

Construction of the U.S. Mexico Border Wall began in the 1990s, today it is over 800 miles long. The most recent editions by former U.S. President Donald Trump added 40 miles to the wall and rebuilt 414 miles of wall.  

If the wall is finished it will be 2,000 miles long, stretching from California to Texas. Concerns about the environment with wall construction are rising as the construction reached Texas.  

The border is meant to prevent human travel between the U.S. and Mexico however it is also stopping wildlife from crossing the border.  

Endangered species in Texas that have been observed crossing the border include American jaguar, ocelot, leatherback sea turtle, loggerhead sea turtle, Mexican gray wolf, peninsular bighorn sheep, and Sonoran pronghorn. 

Two threatened species of owls have flown over the border, the Mexican spotted owl and the cactus ferruginous pygmy owl. These low flying birds may find it difficult to fly over large infastructure.

American jaguars are the only big cat found in the Americas and current populations reside mostly in South America. Four male jaguars have been documented in the U.S.; however no females have been observed crossing the border. Historically jaguars were found in the U.S. states that border Mexico, but are no longer found in large numbers in the U.S. 

Mexican gray wolves and ocelots are predator species that have populations in the U.S. and Mexico. There are over one million ocelots in the world with only 60 in the U.S. compared to a total of 163 Mexican gray wolves left in the wild.  

Two ungulate species the Sonoran pronghorn and the peninsular bighorn sheep are species that do not claim territories and travel through various areas constantly. These species cross the border when migrating due to weather or for breeding purposes.  

These species that are endangered rely on access to South American populations in order to breed. Populations that are unable to breed with other populations are genetically isolated. This isolation stops species from being able to adapt to their environments.  

Genetic variability is important for species to change to their environments and be able to continue evolving. It also increases allele frequency which allows for natural selection to take place.  

The populations of jaguars in the U.S. will be unable to breed if they are unable to cross the border. Jaguars can be helpful in managing species like alligators, snakes, deer and armadillos. 

Habitat fragmentation with the construction of the wall is also a concern. Habitat fragmentation is the destruction of habitat by humans by the construction of roads, movement of heavy machinery and removal of vegetation.  

Habitat fragmentation can be especially damaging to critical habitats, which are habitats that are required for a threatened or endangered species to recover. The wall is being built close to the critical habitat of the cactus ferruginous pygmy owl and the Sonoran pronghorn.  

Another major environmental concern with the border wall is its effects on the pacific and central flyways, which are considered the major routes for bird migrations.  

Light and noise pollution from the wall could disrupt the flight of nocturnal migrating birds as they use light from stars to migrate.