Janos Biosphere Reserve, the habitat of the only wild bison population in Mexico

The Janos Biosphere Reserve is made up of extensive valleys covered with native grasslands that, as they gain elevation, are transformed into forested mountain ranges that offer extraordinary landscapes where the view is lost in the horizon.

Janos Biosphere Reserve, the habitat of the only wild bison population in Mexico
Janos Natural Protected Area. Images: Chihuahua.gob

The Janos Biosphere Reserve is located in the northwestern part of the state of Chihuahua, within the municipality of the same name, bordering to the north with the state of New Mexico, in the United States; to the west with the neighboring state of Sonora, to the east and south with the municipalities of Ascensión, Casas Grandes and Nuevo Casas Grandes, Chihuahua. It has an area of 5,305 km2 and is composed of extensive valleys covered with native grasslands that, as they gain elevation, are transformed into forested mountains that give us extraordinary landscapes where the view is lost on the horizon.

This hitherto little-known region owes its recent decree of protection to the incredible biodiversity it harbors and to the problems of environmental degradation that it is currently facing and that threaten its survival. This is not the first protection decree it has deserved. In 1937, the area between Janos and the municipality of Ascensión was named a Wildlife Refuge by Lázaro Cárdenas and later, in 1979, a ban was enacted on the opening of new agricultural wells because the aquifer was already overexploited.

Within the native grasslands of Janos, we can find one of the largest assemblages of prairie dog colonies in North America, as well as the fauna associated with these peculiar rodents. These rodents are relatives of squirrels, form colonies where they live in family groups and have a complex system of communication among themselves. At the end of the 19th century, they were classified as a pest in the United States due to the false belief that they compete with domestic livestock for available forage, and as a result, the government of the neighboring country has spent millions of dollars in extermination campaigns, achieving their eradication in more than 98% of the area they historically occupied.

The results of these campaigns have been counterproductive, as it has recently been discovered that prairie dogs help keep grasslands free of woody plants, preventing their transformation from grassland to shrubland, due to the dispersal of seeds of plants such as mesquite by domestic cattle and other native herbivores, in addition to providing high-quality forage for domestic cattle during the winter. Livestock activity helps to maintain their colonies and even expand them.

As mentioned earlier, prairie dogs are an important source of food for local wildlife. When one visits their colonies it is very likely to observe coyotes, badgers, and golden eagles waiting for an opportunity to get the day's food. In addition, their burrows provide first-class housing for many of the prairie's inhabitants such as burrowing owls, ornate tortoises, and rattlesnakes. Another characteristic animal of the North American prairies is the bison, and Janos is home to the only remaining wild herd in Mexico, which crosses between the state of New Mexico and Chihuahua every year, venturing a few miles into Mexico.

Its extraordinary natural beauty is characterized by colorful landscapes with vast plains and huge mountains.  Its vegetation includes arid scrublands, grasslands, oak, pine, and other coniferous forests. The fauna of this reserve is one of the most varied in North America; it supports the largest breeding population of the Lesser Short-toed owl and the Golden eagle in Mexico, as well as the only population of wild bison. It is also the habitat of the prairie dog, black bears, deer, bighorn sheep, peccaries, cougars, bobcats, raccoons, hares, rabbits, squirrels, and fish, among others.

Janos is one of the most important sites on the continent for the wintering of grassland birds and the nesting of the endemic Western Mountain Parakeet. Among the environmental services provided by the reserve is water catchment in the mountainous zone and the lower grasslands, as well as the area's biodiversity. Janos was declared a Biosphere Reserve on December 8, 2009.

Janos Biosphere Reserve
Janos Biosphere Reserve

A lost kingdom in northern Mexico

In 1540, Francisco Vázquez de Coronado led a large expedition of more than 2,000 people, including Spaniards and Mexicans, to northern Mexico and the current Southwestern United States in search of the mythical kingdom called Cíbola, which hid seven marvelous cities of gold. For two years they traveled the arid plains without finding gold, but along the way, they observed a series of unknown animals that caught their attention. The first was a beast like a "cow with a hump," which the natives called a cybolo, a name that was used in Mexico until the early 20th century to refer to the American bison, in Latin Bison bison. Although Hernán Cortés had been the first European to observe a bison in Montezuma's gardens, Coronado and his expedition were the first Europeans to see it in its natural habitat. Their accounts highlight the incalculable number of animals that congregated in herds; some speak of 20,000 individuals, while others describe a herd that covered at least 20 km.

On this golden continent also lived a small and sociable animal of barely one kilogram of weight, in colonies formed by thousands of individuals. The prairie dog, as it was called (in Latin Cynomys ludovicianus), is a relative of the squirrels that build burrows and subway tunnels and feed on grasses and herbs. From the beginning, European explorers and naturalists were surprised by their high social complexity, since they live in colonies that resemble "villages". Some explorers even called them "small republics", because they are composed of citizens with complex systems of organization and communication; an example is the watchmen who, always alert, signal the presence of any intruder that threatens the colony using calls similar to the barking of a small dog; the warning call spreads quickly throughout the colony and everyone runs to take refuge.

Until the 19th century, bison and five species of prairie dogs shared this grassland kingdom that stretched from the Saskatchewan prairies in southern Canada to the plains of the Chihuahuan Desert and into northern and central Mexico. Today, Mexico is home to two species of prairie dogs: the Mexican prairie dog and the black-tailed prairie dog. The Mexican prairie dog (Cynomys mexicanus), endemic to the northeastern Mexican Altiplano, inhabits the arid grasslands of the states of Coahuila, San Luis Potosí, and Nuevo León, and the black-tailed prairie dog (Cynomys ludovicianus) is only found in northern Chihuahua and Sonora in Mexico, although it has a wide distribution in the United States. Until the early 1800s, these species covered more than 40 million hectares, while the American bison inhabited a similar area in large herds, with a population estimated at around 30 million individuals.

At the end of the 19th century, traders and hunters joined the explorers and soldiers. The battle against the inhabitants of these ecosystems began. First, the bison fur trade made its way in and began to gradually eliminate this species. The most important consequence of the elimination of bison from the North American landscape was the eradication of the Native Americans who depended on their meat and hides for survival; by eliminating bison, the possibility of survival of these human communities was greatly affected. By the end of the 19th century, the prairie dog met the same fate, due to alleged competition with domestic livestock for pasture and direct conflicts with farmers. As a result of these perception problems, massive extermination campaigns were carried out in the United States, funded by the U.S. Department of Agriculture and designed by biologists working without scientific evidence. Both species reached the brink of extinction at the end of the 19th century when they only survived in 2% of the area in which they had historically been distributed.

In Mexico, what the early explorers and later traders found was not only extraordinary natural beauty; they also found native peoples descended from millennia-old societies that had managed to live in these arid and extreme environments. Societies such as those that inhabited Paquimé and Janos in Chihuahua lived in the plains, mountains, and canyons of this region, and had developed political and economic systems based on agricultural techniques to take advantage of the little water and resources available.

After having survived for centuries, these societies also faced extermination during the evangelization campaigns that were accompanied by the military who ensured that the mission was accomplished; in the end, these lands were divided between the military and other colonizers. The lands turned out to be productive, and that is how the cattle ranching culture of the state of Chihuahua began, which has lasted for more than two hundred years. With this distribution came new human settlers, as well as species of animals and domestic plants: cattle, horses, mules, chickens, sheep, goats, wheat, barley, which would change these prairies for posterity.

During this period, enormous estates were formed throughout Mexico. In Chihuahua, the estates of Dr. José Pablo Martínez del Río or that of General Luis Terrazas -with more than two million hectares- initiated the development of these ecosystems on a large scale. This accumulation of land (often taken from local communities) resulted in the Mexican Revolution. Then, Mexico's social situation and land disputes led to the huge haciendas being divided into smaller properties, and these, over time, into even smaller ones. The division of land, population growth, and lack of education and development alternatives, as well as the lack of enforcement of environmental laws that the region experienced, put a lot of pressure on the resources, and in the areas near the towns, the fauna began to vanish.

This made agricultural fields a daily occurrence in the grasslands of northern Mexico. In the last decade, technological advances have allowed the expansion of intensive agriculture, which in many cases has led to the destruction of pastures. In addition, overgrazing, droughts, and the lack of adequate techniques to develop productive projects and make proper use of the land has caused severe environmental impacts, including the extinction of species, the loss of pastureland, and the increasing desertification of the region. Excessive extraction of water from the subsoil has led to a decrease in water availability, and as the water table (groundwater level) drops, human activities such as livestock and agriculture are directly affected. Even more worrying is the fact that water has become scarce in some communities. Overhunting has caused the extinction of, among others, the grizzly bear and the Mexican wolf in Mexico, and has brought animals such as the pronghorn, bison, and bighorn sheep to the brink of extinction. What was once a biological paradise could become the site of an environmental tragedy if the deterioration processes were not halted. The work of UNAM's Wildlife Ecology and Conservation Laboratory has played a very important role in reversing this trend, as it has sought points of conciliation between local producers and conservation projects to collaboratively recover the grassland ecosystem and endangered fauna.

Wild bison
Wild bison. Image: Conanp

The reconquest of the Kingdom of Cibolo

In the 1980s, rumors about the last remaining grasslands and the existence of important colonies of black-tailed prairie dogs in Mexico pointed to a place north of the city of Casas Grandes and Janos, in Chihuahua. As they began to study it, the area gradually revealed a surprising biological diversity. These grasslands supported one of the largest complexes of prairie dog colonies in the entire continent (55,000 ha) and the most significant complex in the Chihuahuan Desert. It is also home to the only population of American bison in Mexico and some of the last herds of pronghorn (Antilocapra americana) in the state of Chihuahua. Healthy populations of black bear (Ursus americanus), puma (Puma concolor), white-tailed deer (Odocoileus virginianus), and wild turkey (Melagris gallopavo), among other vertebrate species, have been recorded in the highlands. From the mountains descend streams that give life to the plains and forests where species such as the northern porcupine (Erethizon dorsatum) and the wildcat (Lynx rufus) take refuge from the extreme temperatures. The skies are populated by golden eagles, hawks, falcons, plovers, sparrows, tecolote, owls, geese, cranes, and thrushes. The Janos-Casas Grandes region is one of the most important sites on the continent for wintering grassland birds and nesting of the western mountain parakeet, and is one of the most diverse sites for terrestrial mammals in Mexico and North America, surpassed only by the Montes Azules Biosphere Reserve in the state of Chiapas and the famous Yellowstone National Park in the state of Wyoming in the United States.

Paradoxically, at the same time that scientists were demonstrating the biological richness, the growth of human populations and development policies brought with them the uncontrolled increase of agriculture and the degradation of these grasslands, caused by inappropriate livestock practices. Agricultural expansion, overgrazing caused by the introduction of domestic livestock, overexploitation of water bodies, and alteration of the natural cycles of herbivory and fire are some of the factors that have caused the desertification and fragmentation of this ecosystem. Both the excess and the total absence of grazing contribute to the degradation of the system since herbivores need to eat and trample to keep it healthy; something similar happens with fires because when they occur with a certain periodicity, they eliminate the excess of decomposing organic matter and stimulate the growth of native flora.

These problems have opened up new lines of research in the region, in which the effect of human activities on biological diversity and environmental services has been explored. Thanks to this research work, we now understand biological and social aspects related to the prairie dog and the fauna and flora in general, which have allowed us to design and implement strategies for the recovery of threatened species, as well as restoration and management programs for the grasslands. In this way, social participation gained strength and dozens of producers and cowboys in the region turned to see the efforts being made at the site.

Thanks to the work of a large number of people from research institutes, government institutions, civil society organizations, producers, and local communities, the Janos Biosphere Reserve was decreed on November 11, 2009, and a herd of 21 bison from Wind Cave National Park in the United States (taken from one of five genetically pure herds) was released into the grasslands as part of a binational collaborative project. After more than a century, the bison are once again running around the Janos grasslands and the prairie dogs have returned to worrying only about their natural predators. The Janos Biosphere Reserve management program regulates activities within the protected natural area and has been adapting to the needs of the region. Residents and producers have expressed their opinions about the program, and biodiversity conservation strategies have gradually been integrated with agricultural activities, especially cattle ranching. The results of this science-producer interaction have allowed us to design and successfully implement projects that are an example of sustainable cattle ranching and alternative agriculture with clear conservation objectives.

The current realm

Currently, the Janos Biosphere Reserve is a matrix of private properties and ejidos in which cattle ranching and agriculture are the main economic activities and the greatest threat to biodiversity, due to the unsustainable practices implemented in much of the region. Poorly planned agricultural activities and a lack of technical capacity damage wildlife populations and, together with wind and water erosion, have led to soil loss, increased invasion of woody plants, and overexploitation of aquifers. All of these threats have transformed local ecosystems. In recent decades, thousands of hectares have been illegally converted into cultivated fields that seriously threaten the biodiversity of one of Mexico's most productive ecosystems.

For more than 20 years, the Laboratory of Ecology and Wildlife Conservation of the Institute of Ecology of the UNAM has promoted the protection of the site. Currently, the Laboratory continues to develop and implement strategies for the long-term conservation of biological and cultural values in the arid grasslands of northwestern Mexico. This will be achieved by monitoring biodiversity, improving and diversifying natural resource management, recovering threatened species, and developing social participation schemes. Today, thanks to the continuous effort, the passion of many people and institutions, and the will of the inhabitants, thousands of people can feel what the first explorers felt more than 500 years ago when they first saw the vast grasslands, the complex ecosystem, and the majestic animals grazing peacefully in the so-called Kingdom of Cíbola.

Sources: UNAM