President Biden\u2019s administration in August 2023 approved plans for another 20 miles<\/a> in Texas, according to a border patrol update. Opponents of the barrier were highly critical<\/a>, noting Biden had campaigned against the wall while running for president.\u00a0<\/p>\n The 1,954 mile-long borderland between the U.S. and Mexico is often regarded as barren borderland but it contains several highly biodiverse regions for hundreds of mammals, birds and insects.\u00a0<\/p>\n The Lower Rio Grande Valley in Texas alone hosts around 1,200 plant species and nearly 300 butterfly species. The San Bernardino Valley, which straddles the border of southeastern Arizona and Sonora, Mexico, offers another bounty. Researchers recently discovered<\/a> a six-square mile stretch of desert that is home to nearly 500 bee species, one of the highest known concentrations of bees in the world.<\/p>\n Some pollinators have exclusive relationships with certain plants, meaning if they don\u2019t pollinate them, nothing else will. This is the case for a number of solitary bees, which often specialize in one plant species, according to Russ McSpadden, the Southwest conservation advocate for the nonprofit Center for Biological Diversity.<\/p>\n The monarch butterfly, whose caterpillars feed only on the milkweed that the butterflies pollinate, is currently under consideration for the federal Endangered Species List and relies on the borderlands region as a vital migratory corridor and breeding habitat.<\/p>\n Globally, many pollinator species are declining due to threats like habitat destruction and fragmentation, climate change and pesticides. Already, more than 70 pollinating species are listed as endangered or threatened in the United States, according to the Fish and Wildlife Service.\u00a0<\/p>\n A recent U.S.-based study<\/a> found that one in five native pollinators in North America are at elevated risk of extinction and cited the Southwest as home to the highest concentrations of at-risk species. The leading threat is from climate-related stressors, it said. Evidence \u201cis limited\u201d on pollinator activity, the study noted, and \u201cstandardized, long-term, and geographically broad monitoring data\u201d is needed. \u201cKnowing which species are declining, where they occur, and why they are declining is critical for focusing management interventions where they will most benefit at-risk species.\u201d\u00a0<\/p>\n That dearth of information is among the factors that drive citizen groups to try to keep track of\u2014and count\u2014the species in the borderlands.<\/p>\n \u201cNot Just a Wall\u201d<\/p>\n More than 100 miles<\/a> of new border wall and waterborne barriers are currently funded by the federal government, with projects located in the U.S. Border Patrol\u2019s San Diego, Yuma, Tucson, El Paso and Rio Grande Valley sectors, according to U.S. Customs and Border Protection. These projects are in various stages of planning and construction.<\/p>\n Border infrastructure is variable and includes bollard steel structures that rise 18 to 30 feet; concrete levee wall with steel bollards; legacy pedestrian fencing such as chain link or mesh; temporary barriers such as concertina and razor wire; and X-shaped steel obstacles known as Normandy barriers.<\/p>\n The expansion of the barriers has generated worry over big mammals such as jaguars and the impact on their migration patterns, but new tracts of wall will harm pollinators and native plants, said Black, an ecologist who has authored dozens of papers on invertebrates.<\/p>\n \u201cThis is a lot of habitat that will be lost,\u201d Black said. \u201cIt\u2019s not like you\u2019ve got a wall and then you\u2019ve got habitat on each side of the wall. This [land] is cleared because they want to see if people are jumping over. So there\u2019s roads, they clear vegetation. It\u2019s not just a wall.\u201d<\/p>\n He added that \u201cmany thousands of acres of native habitat\u201d have been or will be destroyed to build the wall and provide the infrastructure needed for management and patrols.<\/p>\n The physical structures may play a role in limiting some critical cross-border movement\u2014even if the tiny travelers have wings to fly over the barriers.\u00a0<\/p>\n According to a May study<\/a> from the U.S. Geological Survey (USGS), researchers observed bees, butterflies, moths and wasps in South Texas, along the Rio Grande, for four months in 2023 and 2024 and documented some flight disruptions of the pollinators.\u00a0<\/p>\n Bees flew over the barriers. Most butterflies were able to cross but 7 percent of them retreated or flew parallel to the wall, the study found. Moths were observed crawling through the slats of the wall and 20 percent did not cross but flew parallel to the barrier. Wind and temperature affected some flight distances, but the study found that border walls raised the potential for \u201climitations for pollinators moving across this landscape.\u201d\u00a0<\/p>\n More research was needed to consider \u201cthe deleterious effects on plant biodiversity in both natural and crop vegetation,\u201d author Beth A. Middleton concluded, but she noted that conservationists could anticipate new challenges and possibilities at the border.\u00a0<\/p>\n \u201cThe scope of this study was too limited to support any concerns for genetic flow disruption for endangered plant species populations,\u201d she wrote. But the USGS study could be helpful in planning. \u201cBecause pollinators support endangered plant species, strategies to facilitate their barrier crossing could support plant conservation in South Texas,\u201d according to the study.\u00a0<\/p>\n Black Paint, Bright Lights<\/p>\n Scientists have also raised <\/a>concerns that the border barriers\u2014because of their size and dimensions\u2014could block the movement of non-flying pollinators, the sort of crawling fauna that help spread seeds through daily wanderings.\u00a0<\/p>\n \u201cDesert tortoises can\u2019t make their way across the bollards and they\u2019re incredible seed dispersers,\u201d McSpadden of the Center for Biological Diversity said, explaining that they eat prickly pear cactus, which account for several endangered subspecies. After munching on cacti, the tortoises expel the seeds as they crawl \u201cand that\u2019s one way those plants get distributed and maintain healthy populations,\u201d he said.\u00a0<\/p>\n McSpadden also noted the potential effects of more construction and a new Trump administration initiative to paint the barriers black.\u00a0<\/p>\n This story is funded by readers like you.<\/p>\n Our nonprofit newsroom provides award-winning climate coverage free of charge and advertising. We rely on donations from readers like you to keep going. Please donate now to support our work.<\/p>\n Donate Now<\/a> <\/p>\n Black paint draws in heat. The administration believes by raising the temperature of the wall itself that people will be deterred from climbing. But the heat could also injure pollinators that crawl through the slats or rest on the wall\u2019s surface, McSpadden said.\u00a0<\/p>\n The construction itself is a risk, added McSpadden, who toured a number of areas where border walls were built during President Trump\u2019s first term. The San Bernardino National Wildlife Refuge, located in Arizona\u2019s biodiverse San Bernardino Valley, had no internal roads before the border wall was built during the first Trump administration, he said.\u00a0<\/p>\n \u201cWhen you go out there now, there are these 20-foot-wide dirt roads, and people use them. If you build a road, people will use them,\u201d McSpadden said, adding that research has linked roadways to pollinator risk. A 2021 study in Michigan found that roadways block bee movement and reduce pollen transfer. Vehicle strikes also significantly threaten bees, a study<\/a> in Utah in 2024 concluded.<\/p>\n Stadium lights used to surveil the wall have also been a worry for years, though much of the lighting has yet to be turned on because of pending environmental assessments, McSpadden said.\u00a0<\/p>\n![\"U.S.](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/10\/GettyImages-2201364540.jpg\"\/)
U.S. workers are seen from Ciudad Juarez as they work to reinforce the border wall near El Paso, Texas, on Feb. 25. Credit: Herika Martinez\/AFP via Getty Images<\/p>\n