Elizabeth Webb - American Jaguar: Big Cats, Biogeography, and Human Borders

O ne cold and windy day late in the winter of 1996, near his ranch in the Peloncillo Mountains along the United StatesMexico border, rancher Warner Glenn was on the trail of a mountain lion.

For Glenn, it was the fourth day of a long and grueling hunt, even for a fourth-generation rancher who had spent decades in these lands. For hours the hunter and his hounds stalked the cat through the jagged mountain landscape. Glenn followed on horseback while his dogs moved ahead, rifling through the underbrush, sniffing out rocks and crags, trying desperately to keep on the trail of the elusive and dangerous cat. During the chase, Glenn was astonished by the speed and distance the cat covered across the mountain ridges. It seemed always to be just out of reach, never close enough to get a look, let alone a good shot with his rifle. Occasionally, Glenn spotted unusual tracks. They didnt look like mountain lion tracks.

Finally, after hours and miles of the chase across the mountain ridges and valleys, Glenn and his team of dogs finally caught up to the cat. There, on a bluff high above the desert, the animal stood on a rocky ledge and looked back at its pursuers. But it wasnt a grizzled mountain lion. Instead, Glenn found himself staring at a magnificent, spotted jaguar.

A seasoned cat hunter like Glenn knew the prize he had stumbled upon. No one had seen a jaguar in the United States for decades. This would be the ultimate trophy for any big-game hunter. But instead of raising his rifle, Glenn took out his camera. He began snapping photos of the big cat. Glenns images would become the first photographs of a living wild jaguar in the United States.

The chase soon resumed, and the hunter and his hounds followed the big cat through the mountains. Occasionally, the dogs got too close and the massive beast would hold its ground, spitting and swiping at the pursuing hounds. Glenn wanted to get closer but grew concerned for his dogs. One swing from a frightened and cornered jaguar could easily kill a small dog.

After several hours of pursuitand a host of remarkable photosGlenn and his dogs eventually lost the cats trail. The chase was over as quickly as it began. The jaguar vanished back into the wilds.

Days later, Glenns photos made the local papers. It wasnt long before his encounter with a jaguar made national headlines too. Over the next few years, several other jaguars would be seen roaming the Borderlands. The jaguar had returned to the United States.

Since Warner Glenns groundbreaking photos were taken, scientists have installed cameras around the US-Mexico border to capture more images of jaguars.

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In the Borderlands between the United States and Mexico, the jaguar is fighting to regain its natural habitat. Some say the jaguar has made a triumphant return to the United States. Others say the jaguar never leftthe big cat was here all along, hiding in the most remote areas of the Borderlands.

In the twenty-first century, the jaguar lives in a changing world. Fences, roads, cities, and towns divide the cats realm. Copper mines and farmland further cut up its natural habitat. Even with all these changes, the jaguar still faces its greatest challenge yet: the border wall between the United States and Mexico, should it ever be completed, will ensure the big cat never steps foot in the United States again.

Habitat fragmentation, or breaking up an animals vast territory into smaller unconnected sections, threatens many wild animals. In fact, it might be the biggest threat to all wildlife across the globe. The jaguar is not alone in suffering from the effects of all these changes to the land through habitat fragmentation. The pronghorn antelope and bighorn sheep, as well as the diamondback rattlesnake, the burrowing owl, the spadefoot toad, the monarch butterfly, and countless others are all at risk. Border walls, highways, and other human barriers prevent all of these species from moving freely across their natural landscapes to find food, water, shelter, and mates, directly affecting their populations. Climate change threatens to push many species even further toward the brink. To adapt to changes in temperature and the ecological changes that follow, animals must be able to move freely and without obstacles to areas where they can survive. Scientists and citizens alike are working hard to reconnect landscapes in the Borderlands and beyond. Connections across landscapesand across human bordersare more important than ever. For some creatures, their very future may depend on it.

Chapter 1
Ruler of the Sky Islands

T he Sierra Madre Occidental, or mother mountains to the west, is an immense mountain range that forms the backbone of western Mexico. This towering range starts in the tropical lands of southern Mexico and runs about 780 miles (1,250 km) north to the arid, dry deserts in the state of Sonora, which borders the United States. Here, the mountain range begins to split apart into isolated peaks separated by rolling grasslands and desert. These are the Sky Islands, a loose network of about sixty small mountain ranges. The Sky Islands sprawl northward into the United States in southeastern Arizona.