- The U.S. border wall’s impacts on the flora, fauna and ecological connectivity of a biosphere reserve in Mexico could see the reserve included on UNESCO’s List of World Heritage in Danger.
- El Pinacate and Gran Desierto de Altar Biosphere Reserve abuts onto Cabeza Prieta National Wildlife Refuge in Arizona, but a section of border wall cuts across the boundary.
- The physical barrier has blocked access to water for wildlife on the Mexican side of the border because the natural springs they rely on are on the U.S. side, leading to the death of species like collared peccaries.
- “The fence doesn’t stop the migration of people, but it does stop the free passage of animals and is causing great damage to the biodiversity of the Sonoran desert,” said Alejandro Olivera, the representative in Mexico for the Center for Biological Diversity.
The Mexico-U.S. border wall has interrupted the ecological connectivity of a nature reserve that’s a World Heritage Site, and should be addressed to remedy the situation, according to UNESCO. Without urgent mitigation actions, it says, El Pinacate and Gran Desierto de Altar Biosphere Reserve risks joining the List of World Heritage in Danger.
The northern part of the reserve, located in the state of Sonora in northwestern Mexico, has been breached by an enormous metal fence. This 9-meter-high (30-foot) structure, more than 100 kilometers (60 miles) long, prevents the passage of wildlife to access natural springs located in Arizona.
The Sonoran pronghorn (Antilocapra americana sonoriensis), an endangered species endemic to the Sonoran Desert , is one of many species affected by the fragmentation of its biological corridor between the two countries.
Under the Trump administration in the U.S. from 2017-2021, 732 kilometers (454 miles) of border fence were built along the U.S.-Mexico border. A fragment of the fence was built on El Pinacate’s reserve boundary on the Mexican side and on Organ Pipe Cactus National Monument and Cabeza Prieta National Wildlife Refuge on the U.S. side in the state of Arizona.
The Tucson, Arizona-based Center for Biological Diversity (CBD) said in a statement that the fence “blocked the critical migration of wildlife in and out of this protected habitat, endangering the connectivity and integrity of the area.” The organization, which works to protect threatened species and wild places, says the fence now runs 140 km (87 mi) along the border of El Pinacate, leaving only 23 km (14 mi) of mountainous terrain without a barrier.
“There were oases left on the U.S. side. Many animals migrate and look for water in the desert, but now they cannot access the sites that were available for thousands of years,” biologist Alejandro Olivera, the CBD representative in Mexico, told Mongabay Latam. He said that in the past there were only barriers to stop the passage of vehicles, while the animals moved freely, “but now they are faced with an impenetrable 9-meter-high wall.”
Of the existing water sources, Quitobaquito Springs is the best known. In addition to supporting wildlife, it’s also a sacred site for the binational Tohono O’odham Indigenous people, who have rejected the border wall. “Quitobaquito is practically a few meters from El Pinacate and the border fence, but now it is in the United States,” Olivera said.
UNESCO published a document in mid-September 2023 calling on the United States and Mexico to form an urgent action plan to assess and mitigate the impacts of the fence, with the objective of restoring ecological connectivity. It also cited the need to monitor key species, implement a tailored recovery plan for the Sonoran pronghorn, and develop conservation measures to accompany the proposed electricity transmission network for the solar power plant being built by Mexico’s Federal Electricity Commission (CFE) in Puerto Peñasco, Sonora. The plant is intended to be the largest in Latin America and will also affect the buffer zone of El Pinacate.
All of these measures should be presented in a report that includes the state of conservation of the reserve. The information must be submitted to UNESCO’s World Heritage Centre by Feb. 1 for evaluation by the World Heritage Committee at its 46th session, to be held in July.
“The ideal would be to remove [the fence] in all areas that correspond to the reserve,” Olivera said. “The fence does not stop the migration of people, but it does stop the free passage of animals and is causing great damage to the biodiversity of the Sonoran Desert.”
World Heritage in Danger
In February 2022, the Mexican government published a report on the state of conservation of El Pinacate. It noted that the border fence — which includes a solid metal wall, a parallel mesh wall, barbed wire, and service and surveillance roads — “will inevitably have effects on the biodiversity and the Outstanding Universal Value (OUV) of the property.” The report warned of habitat loss, degradation, and fragmentation, as well as reduced access to resources, isolation and fragmentation of wildlife populations such as the Sonoran pronghorn, increased human activity, and diminished water resources.
Based on the report, UNESCO, the U.N. agency responsible for conferring World Heritage status, called on Mexico’s National Commission on Natural Protected Areas (CONANP) and the U.S. National Park Service (NPS) to establish a collaborative program to restore connectivity between northwestern Sonora and southwestern Arizona.
“[I]f ecological connectivity is not ensured or restored to safeguard the viability of key populations, the property may meet the conditions for inclusion on the List of World Heritage in Danger,” UNESCO’s World Heritage Committee wrote in response to Mexico’s report.
Mongabay Latam requested a comment from CONANP regarding UNESCO’s requirements but didn’t receive a response as of the time this story was originally published.
According to UNESCO, only “cultural and natural heritage properties threatened by serious and specific dangers” may be included on the List of World Heritage in Danger. These include, among other threats, the possibility of disappearance due to accelerated deterioration, major public or private works projects, rapid urban and tourism development, destruction due to changes in land use or ownership, armed conflict, or various natural phenomena.
By 2020, of the 1,121 World Heritage Sites around the globe, 53 were on the List of World Heritage in Danger. Adding a property to this list “allows the World Heritage Committee to immediately allocate emergency assistance to the threatened property from the World Heritage Fund. It also alerts the international community to join efforts to save these properties,” UNESCO said.
Wildlife dying of thirst
Along the large metal border wall, experts have detected large mammals that have died of thirst. The carcasses of species such as collared peccaries, deer and desert bighorn sheep (Ovis canadensis mexicana) have been found in the vicinity of the wall or in nearby caves. So far, no Sonoran pronghorn carcasses have been seen, but the species’ situation is still alarming, as only 85 individual pronghorns have been observed on the Mexican side of the border since 2022.
“We have not found dead pronghorn, but that is explained by the fact that they are much scarcer,” said Federico Godínez Leal, who was director of El Pinacate and Gran Desierto de Altar Biosphere Reserve from 2004-2017. “Of course, we have to continue with field assessments and interpreting more than half a million photos and videos we have in camera traps. It’s material to analyze and to obtain results, but that implies a lot of effort and resources that we don’t have.”
“Both Quitobaquito and Tinajas Altas, which is another permanent spring, are to the north of the wall. Quitobaquito is only 50 meters [164 ft] from the wall, to the north, and Tinajas Altas, which is a little larger and is where the bighorn sheep used to get their water, was also closed off to the west,” Godínez Leal said.
The former park director knows well the area because, in addition to having been in charge of the reserve, he also studied it for more than two decades as a zootechnical agronomist. Today, Godínez Leal is the director of the Magool Foundation, which he founded with his family in 2013 to focus on social health and environmental care.
Starting in 2021, Magool Foundation representatives have traveled in the border area of the reserve to develop a water supply program for species affected by the border wall, in collaboration with the ejidos, or communal farmlands, of Toboyori II and Vicente Guerrero. Together, they transported and installed water tanks able to hold a combined 150,000 liters (40,000 gallons) from the neighboring municipalities of Sonoyta and San Luis Río Colorado.
“There are no wells there. We get water from the firefighters, more than 100 kilometers from the site,” Godínez Leal said. He added that “no action is seen from the American government and, curiously, the Mexican government has not said anything either. The only thing that is known is UNESCO’s recommendation to both countries to establish and begin actions to restore ecological connectivity.”
Godínez Leal said the situation is complicated and the only medium- and long-term solution is collaboration between both governments. “Otherwise, it would not be possible to achieve very good results, but rather we would be left trying to solve it. It will be difficult, we will try, but we will see what result is obtained,” he said.
Banner image: Cabeza Prieta National Wildlife Refuge and El Pinacate Biosphere Reserve, separated by the U.S. border fence. Image courtesy of Russ McSpadden/Center for Biological Diversity.
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