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Friday, May 27, 2022

Jaguars can return to the southwestern United States – but only if they have roads to move north

Jaguars are the only species of big cat found on the American continent. They extend as far south as Argentina, and once wandered as far north as the Grand Canyon in the United States. Today, the northernmost breeding population is in the northwestern Mexican state of Sonora, just south of the Arizona border.

In the Americas, the jaguar has long been an icon and symbol of power and connection with the spiritual world in mythology, philosophies, culture and art. Jaguars are top predators with diverse diets that include more than 85 different prey species. This gives them a specific but prominent role in each ecosystem where they are found.

The International Union for Conservation of Nature classifies jaguars as “almost endangered”, with total population estimates ranging from 64,000 to 173,000. But evidence shows that local populations across the continent are declining at an alarming rate. Jaguars’ total range has shrunk by more than half over the past 70 years, mainly due to hunting and habitat loss.

Can jaguars return to the Southwestern United States? Some experts believe this is possible. Jaguars from southern populations in Mexico could recolonize their former territories in Arizona and New Mexico, or people could bring them back there.

Current range of jaguars in Mexico (green zones). Dots represent observations, and numbers indicate jaguar conservation areas.
Ceballos et al., 2021, CC BY-ND

We study biodiversity and wildlife conservation in the borderlands between the USA and Mexico and have documented jaguar movements near the border. From our research we know there are only two main aisles in the western borderlands that jaguars can use to get into the US

In our opinion, the maintenance of these passages is crucial to connect fragmented habitats for jaguars and other mammals, such as black bears, pumas, ocelots and Mexican wolves. Increasing connectivity – linking small patches of habitat in larger networks – is a key strategy for conserving large animals spanning vast areas and for maintaining functional ecological communities.

The northern jaguars

The arid environment of the American Southwest, of course, limited the distribution of jaguars in North America. Once upon a time, these cats were top predators in the wooded ecosystems of the southwestern United States, but predator control programs and hunting destroyed their populations in the 19th and early 20th centuries. The last female jaguar in the USA was killed in 1949 in Arizona.

In 1996, an outdoor guide and a hunter photographed a male jaguar in the Peloncillo Mountains in southeastern Arizona. Since that date, other jaguars have been identified, but no females or cubs have been reported.

In contrast, jaguars are known to be present in the northeast corner of Sonora State in Mexico. Here, the Cajon Bonito stream, which flows from the western slope of the San Luis mountain range into the Continental Divide, supports jaguars and other large animals, including black bears, American beavers and ocelots.

El Bonito, a jaguar living on the border between Mexico and the United States, uses the Cajon Bonito area northeast of Sonora.

Countries around the stream have been under a restoration program run for two decades by Cuenca Los Ojos, a non-profit organization working to protect and restore land on both sides of the border. They are now part of a voluntary protected area program under Mexico’s natural protected area system.

To the east, the Janos Biosphere Reserve includes habitat for jaguars. North and south, a combination of farms dedicated to conservation and natural protected areas provide the habitat connection that jaguars need to move between Mexico and the US

Varies in the border countries

In 2021, we filmed a young jaguar we called El Bonito roaming the borderlands between the US and Mexico. Each individual jaguar has a unique pattern of spots on its skin; when we obtained videos of both of the cat’s flanks, we realized that we were actually seeing two jaguars in our study area.

We christened the second jaguar Valerio. Recently, he has been spotted more frequently than El Bonito in the Cajon Bonito stream area.

After El Bonito, a second male jaguar appeared in our camera traps in border states between Sonora and Arizona. We named him Valerio.

Male jaguars need to disperse as they become adults to find available areas and potential mates. Females tend to occupy areas near where they were born, a pattern commonly found among mammals. The size of a female jaguar’s territory depends on the abundance of prey and the availability of shelter. Jaguar males will travel across several female home ranges to increase their mating opportunities, so males’ house ranges can measure from about 15 to 400 square miles (35 to 1,000 square kilometers).

El Bonito and Valerio were teenagers when we first recorded them. We filmed Valerio for the first time in January 2021 at our campus. Since then, both cats have used the stream as a passage. Recent videos show Valerio rubbing a fallen tree on the cheek, indicating that he is establishing an area in this border area.

At our campus, we both recorded jaguars just 2 miles (3 kilometers) south of the U.S.-Mexico border. North of this site is Guadalupe Canyon, a natural passage in the Peloncillo Mountains that runs in the U.S. on the border between Arizona and New Mexico.

In 2021, the boundary wall across Guadalupe Canyon was built and stopped at the Arizona-New Mexico line. The New Mexico portion of the Peloncillo and San Luis mountain ranges remain open.

Workers add slats to a barrier over shrub-covered ground.
Construction on the boundary wall in Guadalupe Canyon, Arizona, southbound to Mexico, December 9, 2020.
Associated Press Photo / Matt York

Keep corridors open

U.S. and Mexican government agencies and conservation organizations are working together to restore Western species on the verge of extinction. Growing populations of Mexican wolves, black-footed ferrets, California condors and bison offer hope that recovery is also possible for jaguars.

According to a 2021 study, the population of jaguars in Mexico has increased over the past decade and is now estimated at 4,800. As the number of jaguars in Sonora increases, so do the chances that females can reach the border and possibly mate with the male jaguars we have documented there.

Habitat loss and illegal killings are still the biggest threats to jaguars in northern Mexico. The creation of natural protected areas that can support breeding populations and provide routes for northern expansion will help accelerate the natural recolonization of jaguars to the USA. Multiple institutions and scientific research projects have highlighted the need to keep natural corridors open to maintain habitat for diverse communities of plants and animals. .

A windswept grass hill with mountains in the distance.
Views of the Peloncillo Mountains, a corridor still open to wildlife movements between Mexico and the USA. The photo was taken in the Mexican borderlands looking north to New Mexico.
Ganesh MarinCC BY-ND

In addition to jaguars, our camera traps have identified 28 other species of mammals, including ocelots, pumas and black bears. All of these animals have at least some need for linked landscapes if they want to survive for the long term.

In our opinion, this is a unique opportunity to promote animal movement in the borderlands to enable jaguars to recolonize a naturally suitable habitat in the USA. Keeping these landscapes connected will benefit all species in this ecologically unique region that serve as a wildlife resource and road.

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World Nation News Deskhttps://www.worldnationnews.com
World Nation News is a digital news portal website. Which provides important and latest breaking news updates to our audience in an effective and efficient ways, like world’s top stories, entertainment, sports, technology and much more news.
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