BY PAM DELANY
In the heart of the borderlands, a jaguar moves silently through the dappled light of an oak woodland, its spotted coat blending seamlessly with the shadows. Once believed to have vanished from the United States, this elusive predator still roams the Madrean Sky Islands, isolated mountain ranges that rise abruptly from the desert floor, creating a mosaic of ecosystems found nowhere else on Earth. The presence of jaguars here, along with a dazzling array of butterflies, rare plants, and endemic species, highlights why this region is considered one of the world’s most important biodiversity hotspots.
Conservation International defines biodiversity hotspots as areas with exceptionally high numbers of endemic species (i.e.,geographically limited and native) that are also under significant threat. To be designated as a biodiversity hotspot, an area must have at least 1,500 species of vascular plants that exist nowhere else and must have lost at least 70% of its original vegetation. Despite covering just 2.5% of the planet’s land surface, these hotspots support more than half of the world’s endemic plant species and 43% of endemic animal species.
The Madrean Pine-Oak Woodlands, stretching from northern Mexico into the southwestern U.S., is one of only three hotspots in the United States. Within it, the Madrean Sky Islands, about 40 distinct mountain ranges in Southern Arizona and Northern Mexico, including Chiricahua, Dragoon, Santa Catalina, Rincon, Huachuca, and Santa Rita, offer a striking example of how geography shapes biodiversity. Rising from 3,000 to over 10,000 feet, these mountains create habitat islands ecologically distinct from the surrounding desert lowlands, supporting thousands of unique species that thrive in their own microclimates.
“It’s where the jaguar and black bear meet, where bromeliads grow in the arms of maple trees, and where the spicy chiltepin pepper thrives alongside the Arizona canyon grape,” explains Louise Misztal, executive director of Sky Island Alliance. “The diversity of elevation, habitat, and climate supports an incredible wealth of species that are found nowhere else.”
Indeed, the numbers are astonishing: Around 5,300 species of flowering plants, 525 bird species, 330 mammals, 380 reptiles, and more than 160 butterfly species are found in the Sky Islands. They are home to over half of North America’s bird species and 120 out of the 150 reptile and amphibian species found in Arizona. Among them are rare and delicate species like the Arizona giant skipper, a butterfly found only in these high-elevation woodlands, and the ancient leopard frog, thought to be extinct before being rediscovered in isolated mountain streams.
Butterflies are among the most fascinating residents of the Sky Islands, with species like the Mexican bluewing and the two-tailed swallowtail, Arizona’s state butterfly, thriving in these mountainous habitats. According to Patagonia Area Resource Alliance, the Patagonia community in Arizona is the pollinator capital of the United States, with over 300 types of butterflies and moths, 600 species of native bees, 14 hummingbird species, and two nectar-feeding bat species. These essential pollinators support plant reproduction in their delicate habitats.
Despite their ecological significance, the Sky Islands face an array of threats. Climate change, habitat fragmentation, and human development continue to encroach upon these delicate ecosystems. “The border wall has created a physical barrier that severs vital wildlife corridors,” says Rodrigo Sierra Corona, executive director of Borderlands Restoration Network. “Species like the jaguar, ocelot, and mountain lion rely on these linkages to move between Mexico and Arizona. Man-made barriers are isolating populations and increasing their vulnerability to extinction.”
The region’s mineral-rich mountains have also attracted interest from extractive industries, such as large-scale mining projects that could devastate the fragile ecosystems that make the Sky Islands so unique. Open-pit mines strip vast areas of vegetation, pollute waterways, and create toxic runoff that threatens both wildlife and local communities. The Patagonia Area Resource Alliance, a grassroots organization dedicated to protecting the Patagonia Mountains and surrounding ecosystems, has been a key force in resisting mining expansion. The alliance works to monitor mining activities, advocates for stronger environmental regulations, and engages local communities in conservation efforts.
Additionally, water scarcity looms large. Springs and streams, lifelines for the region’s biodiversity, are drying up as climate change alters rainfall patterns. Organizations like Sky Island Alliance, Borderlands Restoration Network, and Patagonia Area Resource Alliance are leading efforts to restore these critical resources. From removing invasive plants to reintroducing native vegetation and employing erosion control techniques, conservationists are working to ensure that the Sky Islands thrive for generations.
Local conservation efforts, community engagement, and policy advocacy continue to make a difference. Sky Island Alliance’s Spring Seeker program, for example, trains volunteers to monitor and restore desert springs, while Borderlands Restoration Network’s Native Plant program provides the foundation for habitat recovery across the region.
For the Tohono O’odham Nation, these lands are more than ecological wonders; they are sacred. The recent naming of Arizona’s newly discovered jaguar by Tohono O’odham students and elders is a powerful reminder of the deep cultural connection Indigenous communities have with the land. The jaguar’s name, O:shad Ñu:kudam, means “Jaguar Protector.”
“As O’odham, we view jaguars as protectors of our people and the environment. O:shad Ñu: kudam’s presence serves as a powerful testament to the resilience of nature and the importance of ongoing conservation efforts. We are committed to working to ensure a safe and thriving future for O:shad and one day hope to see the return of a breeding population of jaguars to this region,” said Chairman Austin Nunez of the San Xavier District in a 2024 press release.
This cultural and ecological significance underscores why protecting the Sky Islands is not just a conservation effort but a broader movement to honor the land’s history, biodiversity, and Indigenous culture.
“These mountains sustain us — clean air, flowing water, pollinators, and the deep sense of place that comes from living in a biodiverse landscape,” says Misztal. “We all have a role to play in ensuring that the Sky Islands remain wild, connected, and thriving.”
For Arizonans, the Madrean Sky Islands are a living testament to nature’s resilience and the intricate balance that makes this place unique. Protecting them is not just about preserving a landscape; it is about safeguarding a legacy that belongs to all living beings who call this land home. To learn more, visit www.skyislandalliance.org.
