When biologist Ganesh Marin first observed a jaguar at a reserve in northern Sonora, Mexico in 2020, he was thrilled. The feline continued to appear on Marin’s grid of camera traps along the Arizona border, indicating that he made the area his home. Marin nicknamed the jaguar El Bonito, Spanish for “the beautiful one”.
But in 2021, Marin, a National Geographic explorer, noticed something strange in the photos. The dot patterns seemed to vary very slightly from image to image. Further examination confirmed that he was indeed seeing not one, but two young male jaguars.
It had been quite exciting to watch Bonito develop in front of the camera, “growing, getting bigger, having a thicker neck and a bigger head,” says Marin. But realizing there was more than one: “It was pretty exciting.”
The presence of a second jaguar a few miles south of the Arizona border provides even more evidence that the big cats are moving north to reclaim former territory, says biologist and dean of the University of Wyoming and Ph.D. from Marin. advise. (Related: Why a New Jaguar Sighting Near the Arizona-Mexico Border Gives Experts Hope.)
As late as the early 1900s, jaguars were found as far north as the Grand Canyon and as far south as Argentina. But hunting, often government-sponsored, drove them out of Arizona and New Mexico, the northern extent of the jaguar’s range, in the mid-20th century.
Marin named the second jaguar Valerio, after Valer Clark, a conservationist who founded the organization Cuenca Los Ojos. This binational environmental organization now operates a 121,000-acre wildlife sanctuary along the border in Sonora, where Marin does his research as a doctoral student at the University of Arizona.
The cats could expand their territory north if humans let them, but they face obstacles such as roads and the US-Mexico border. More than 450 miles of 30-foot-tall walls have been built under the Trump administration, most of them in Arizona and New Mexico, blocking vital wildlife corridors. (Read more: Arizona border wall will include openings too small for many animals.)
“There are animals right there a few kilometers from the border that could easily be prevented from moving further north if the border becomes impermeable,” Koprowski said, due to the extension of the border wall and the expansion highways.
“But more than anything, the [finding] offers great hope that this connectivity can be maintained,” he says, and even, perhaps, improved.
The border regions of Arizona and New Mexico, and its series of mountain ranges, known as the Sky Islands, represent one of the most biodiverse regions in North America. Interspersed with mountains are the dry plains of the Sonoran and Chihuahua deserts and diverse grasslands and riparian areas, collectively home to tens of thousands of species of plants and animals. For eons, jaguars, cougars, ocelots, bears, and many other large-scale species have roamed freely in this contiguous biome. But barriers such as roads and fences now impede this movement.
Nonetheless, in the past 25 years, at least seven jaguars have been seen in Arizona – including one that still lives in a mountain range in the southeastern part of the state – and roughly the same number have been sighted. across the border in Mexico.
Additionally, a March 2021 study estimates that much of the area is prime jaguar habitat and could likely support a population of a few hundred animals. Jaguars are classified as an endangered species in the United States.
Some 200 jaguars live in the Mexican state of Sonora, and the two cats observed by Marin were likely born somewhat near Arizona, perhaps less than 60 miles away, says National Autonomous University researcher Gerardo Ceballos. from Mexico.
Female jaguars generally do not venture very far from their birthplace and their mobility is the limiting factor in the expansion of the species. Males, however, can wander very far in search of territory and mates. Big cats face a variety of threats in Mexico, including poaching and retaliatory killings for their perceived role in livestock predation.
“If we keep trying to protect jaguars, maybe in about five years we could see pregnant females in the United States,” Ceballos said.
But to move north, felines need protected wildlife corridors. Any extension of the border wall will further harm animals’ ability to move freely – and parts of the wall will need to be opened up to reduce the damage it has already caused, experts say. The Biden administration has pledged not to significantly expand the border wall, and some discussions are underway to mitigate wildlife damage, although no major changes have yet been made.
“Unfortunately, the border wall now represents a new barrier for jaguars to reach the United States,” says Antonio de la Torre, a biologist with the Jaguares de la Selva Maya conservation group, which studies the big cats. “Implementing a mitigation measure to address this issue is essential if we are to ensure the natural northward expansion of jaguars.”
If you protect it, they will come
Until recently, much of what is now northern Sonora and southeastern Arizona had numerous wetlands, known in Spanish as the cienegas. That’s why Cuenca Los Ojos is working to bring water back into the landscape and has so far restored about 75 acres of wetlands and streams, says Jeremiah Leibowitz, the organization’s executive director.
Prior to 2019, the 30-mile northern border of Cuenca Los Ojos, which adjoins Arizona, had only short vehicle barriers and barbed wire fences a few feet high, which wildlife could easily cross. . But now it’s lined with 30-foot steel bollard walls, Leibowitz says. However, a few corridors remain devoid of such high barriers, such as the southern end of the Peloncillo Mountains that straddle Arizona and New Mexico. (Read more: An endangered wolf has gone in search of a mate. The border wall blocked it.)
This area, like much of its surroundings, receives half or more of its rainfall during the monsoon season, from June to September. After European settlement, people changed the landscape to be much less absorbent, replacing grasslands with agriculture and building impermeable structures, including asphalt. As a result, this rain can quickly run off the land, causing erosion.
Cuenca Reserve managers are working to restore the land’s original permeability, in part by slowing water with erosion-control stone structures, Leibowitz says. Beavers, whose dams also control water flow, have also recently recolonized many streams in the reserve. The two Sonoran jaguars were seen near a creek in the reserve that flows year-round.
Establish a range
Valerio and Bonito sometimes frequented the same area within days of each other, according to camera trap data. As they grew, Marin figured one would push the other out – when they reach breeding age, male jaguars try to establish their own territory.
Sure enough, Valerio, who is still a bit taller, remained – he was last seen in March – while Bonito has not been seen since October 22, 2021. Marin suspects he is somewhere in proximity, but since animals can move so widely, it’s someone who guesses.
In addition to searching for wildlife using cameras, Marin worked with biologists Melissa Merrick, Katie Benson and Matt Valente to sample environmental DNA from some of the streams, which revealed evidence of jaguars, bears black, white-tailed deer, deer mice and others. local fauna. The team hopes to expand its sampling and study of eDNA to learn more about the presence of terrestrial fauna, a practice that remains in its infancy, Benson said.
In the meantime, research shows that the region is home to a host of important species and that restoring habitat can increase a region’s biodiversity.
“The fact that animals use this area over and over again is all a testament to the quality of the habitat and the need to increase that connectivity” with surrounding areas of Mexico and the United States, Koprowski says.