Sky Islands - Chiricahua, © Roxie Crouch
© Roxie Crouch

Sky Islands

Threats to Sky Islands

Threats to the ecological functioning of the Sky Islands region are intertwined, and their combined impacts are enormous.

Climate Change

Hotter, drier conditions drive animals to seek cooler refuges, which in the Sky Islands means moving up a mountain. But as warming continues, even the tops of the Sky Islands will become too warm for many species. Changing climates can also allow invasive species to gain a foothold and compete with already imperiled native species.


Particularly in the remaining riparian areas in the Southwest, overgrazing damages the soil, leading to the loss of native plants and their associated species. Even fish are harmed by overgrazing, which erodes stream banks, muddying the water.  Overgrazing along streams can also cause the loss of tall plants which shade, and therefore cool, the water.

Fire Suppression

The Sky Islands and their plant and animal communities evolved with a natural regime of periodic fires. Decades of fire suppression have changed the natural systems here, and fire is needed to restore them. More frequent, less-intense fires keep fuel from building up, which results in less-destructive fires.

Loss of Predators

The loss of big predators is another threat to the health of the region. Apex predators like wolves and jaguars are nature’s wildlife managers, keeping elk and deer herds in check and healthy, leading to healthier ecosystems.

Energy Development and Mining

These industries often follow a “boom and bust” cycle that provides temporary profits at the cost of long-term or permanent destruction of natural habitats. In the Sky Islands, copper mining is a real threat, particularly to jaguars and ocelots that are struggling to regain a foothold.

Border Issues

The Sky Islands also face fragmentation and destruction of habitat because of the building and maintenance of the U.S./Mexico border wall. The wall—15 feet high in some places—prevents many species from reaching food and water sources. It also curtails the search for mates. Border operations, including patrol traffic, lights, the use of off-road vehicles and the building of various camps and bases also destroy habitat and disrupt the movement of animals.