Sky Islands

View across a valley with distant mountains on the far side. In the foreground are rock pinnacles and spires.
The Chiricahua Mountains are one of many sky islands stretching across southern Arizona. From this view, the Dragoon Mountains on the other side of Sulphur Springs Valley also rise up like an island from the sea of grass.

NPS

Chiricahua National Monument is one of several sky islands in southeastern Arizona. A sky island is an isolated mountain range that rises up out of the surrounding desert “sea.” The Chiricahua National Monument Visitor Center is 5,400 feet (1,646 meters) above sea level. The high point in the Chiricahua Mountains – Chiricahua Peak – is 9,795 feet (2,986 meters) above sea level. The Chiricahua sky island rises about 6,000 feet (1,829 meters) above the Sulphur Springs Valley. Sky islands are part of the larger Basin and Range Province.

Sky islands are unique. As the elevation changes, so do the surrounding ecosystems. As the altitude increases, the temperature decreases. The amount of breathable oxygen in the air also decreases the higher up you go. Conditions often vary from the bottom of Chiricahua National Monument to the top. Near the lower elevations, the monument tends to get hot summers and mild winters. whereas near the higher elevations, there are more mild summers and frigid winters. When it is raining at the lower elevations, it could be snowing higher up. The average precipitation at the bottom is 15 inches (31 centimeters) per year, but it can be twice as much at the top. The higher elevation of Chiricahua creates different weather conditions from the lower valleys.

The sky island’s special environment results in extraordinary biodiversity. The monument is located at a crossroads between four major ecosystems. The Rocky Mountains, Sierra Madre, Sonoran Desert, and Chihuahuan Desert converge here. The monument also has characteristics of five world biomes: Desert; Grasslands; Chaparral; Deciduous Forest; and Coniferous Forest. Biomes are large areas of plant and animal groups that are adapted to a specific environment. Biomes are characterized by abiotic, or non-living, factors like climate and geology. In Chiricahua, these characteristics mix together to create a unique mosaic of environments. Many species of wildlife and plants can be found at all elevations of the monument.

Learn more about the natural and cultural resources of the American Southwest.
 
Three images: a palm-like yucca, a spiny lizard on a rock, and a prickly pear cactus in the snow
Plants like the Schott's Yucca (left) and prickly pear cactus (right) have adaptations to conserve water. Reptiles, like this Yarrow's Spiny Lizard (center), will use burrows to escape the heat.

NPS

Desert Biome

  • Hot and dry, characterized by little to no rainfall.
  • In Chiricahua, this environment can primarily be found on the west side of the monument.
  • Short shrubs and cacti thrive in the desert environment. These plants have developed adaptations that help them to survive in the harsh, arid land.
  • The prickly pear cactus has a specialized root system that allows them to reach and retain water. This plant has also developed sharp spines instead of leaves. This helps to protect them from animals in the desert.
  • The yucca has long, palm like leaves stemming out from the center. This plant has developed a thick, waxy coating on their leaves to prevent water loss. Like the prickly pear, it also has specialized roots to help it reach as much water as possible.
  • Wildlife in the desert includes animals that are able to, like the plants, conserve water. The spiny lizard uses burrows, or underground holes, to escape the heat of the desert. Their thick, scaly skin helps prevent water inside their bodies from evaporating.
  • The kangaroo rat is mostly nocturnal, and avoids going out in the heat of the day. They also have very oily coats and don’t sweat to help them conserve water.
 
Two images: a yellow, grassy hillside with sparse shrubs and agaves and large monsoon clouds behind it. Right image is a coyote on a hillside with a valley behind it.
This hillside near the entrance to Chiricahua National Monument is a great visual for the Grasslands Biome. Coyotes (right) are a common predator and are often seen in and around the monument.

NPS

Grassland Biome

  • Regions with extensive grass and sparsely distributed trees.
  • Occur on gentle slopes and plains.
  • Grasslands are areas that have potential to develop into a forest, but due to drought, fire, or other factors, trees are prevented from establishing.
  • Temperatures begin to become too low (cold) for many desert shrubs.
  • To the west of the monument, over 50 species of grass thrive, including the blue grama, a dominant species in grassland prairies and a valuable forage plant.
  • Low diversity, but high abundance of wildlife.
  • One of the notable predators here is the coyote, which benefits from natural camouflage. Their fur varies from light brown to grayish, helping them blend into several different environments, including the grassland. This allows the coyote to sneak up on their prey and either pounce on it or run up to 40 miles per hour (64 kilometers per hour) to catch it.
  • One of the notable prey animals of the grassland is the jackrabbit. The long ears are thin and full of blood vessels that help the jackrabbit stay cool. To combat rising temperatures, jackrabbits regulate the flow of blood through their ears by dilating their blood vessels. This allows heat to escape, cooling the jackrabbit in the process.
 
three images: green shrub with red branches and trunk; a deer standing among oak trees and a yucca; and a javelina (pig-like) in tall yellow grass.
The red-barked manzanita is an important resource for many birds and mammals. Deer are found throughout the monument, like this one near the visitor center. Javelina are relatively common at the lower elevations.

NPS

Chaparral Biome

  • Unique mix of other biomes’ characteristics.
  • Similar to desert biome, but receives more annual precipitation: 10-17 inches (25-43 centimeters).
  • It features both forest environments and grassland environments.
  • During winter, temperatures can drop below freezing and summers can reach 100℉ (38°C).
  • Usually dry, typically borders a desert biome, and has many of the same plants and animals.
  • Vegetation grows on exposed ridges where sunlight is high and wind is nearly constant.
  • The manzanita is a small shrub that is well known for its red bark, as well as its twisty branches. The pointleaf species of manzanita has long, sharp-pointed leaves with rather leathery surfaces. It is adapted to living on rocky ledges and on fine soil
  • A unique animal that can be found in a chaparral environment is the javelina, also known as the collared peccary. This animal is famous for resembling a pig or boar, however, it is NOT a pig. They are known to travel in large family groups, defending their sleeping and feeding areas as a team. Javelina have a scent gland on top of their rump, and they will rub their scent on rocks and trees to mark their territory and help with identification.
  • The most common rattlesnake in the monument, the black-tailed rattlesnake, lives in many biomes, though it appears to be most abundant in woodlands. This large snake is easily distinguishable from the Western Diamondback and others by its distinctive black tail near the rattle. This snake uses heat sensing ‘pits’ to detect warm-blooded predators and prey. This animal is very well-known for its defense (and predatory) mechanism – injecting venom from its fangs. For safety, always watch your step while you’re hiking, don’t put your hands or feet anywhere you can’t see, and if you encounter a rattlesnake, slowly back away.
 
Three images: a white-barked tree with orange, green, and yellow leaves; a large oak tree with sprawling branches; and a cinnamon-colored black bear.
Arizona Sycamores (left) are easy to identify with their white bark. Like many other deciduous trees, their leaves turn colors in the fall. Most oak trees (center) in Arizona turn colors and drop their leaves in the spring. Black bears come in different shades, like the cinnamon-colored one.

NPS

Deciduous Forest Biome

  • In Chiricahua, this is an oak woodland or riparian forest. Riparian means the forest is found near a water drainage-way. Washes wind through the park and flow when there is a lot of snowmelt or if there is a monsoon.
  • Four distinct seasons.
  • Lots of trees provide food and shelter for wildlife.
  • Trees include sycamores and oaks, including the Arizona white oak, which is best suited for two seasons of rain, warmer summers, and mild winters.
  • This biome is home to many larger animals in the monument.
  • The Arizona white-tailed deer, or Coues Deer, is the most commonly seen animal in the monument. It is a rather small deer compared to other species. They browse on woody plants. As an alarm signal, white-tailed deer lift their tails and show the fluffy white underside when they feel startled or threatened.
  • Another famous resident of the woodlands is the black bear. ‘Black bear’ is a misnomer; the black bear can be brown, black, cinnamon, or even blonde. They will eat almost anything, and have extremely long claws on their front feet for digging and overturning rocks. In Chiricahua, the bears become less active during the winter months, but unlike most bears, they do not ‘truly’ hibernate.
 
three photos: square-shaped bark; a mountain lion in a dry wash; and long-needled pine tree branches against a blue sky.
Alligator junipers (left) and Apache pine (right) can be found throughout the monument, but are indicative of the coniferous forest biome and are more common at higher elevations. Mountain lions (also known as pumas or cougars) are infrequently seen by park visitors, but can be active at any time.

NPS

Coniferous Forest Biome

  • Coniferous trees are characterized by having either needle-like or scale-like leaves that remain green throughout the year.
  • Cooler climate than the deciduous forest (due to elevation in Chiricahua).
  • Long, snowy winter and hot, wet summer.
  • One of the trees in the coniferous forest environment is the Alligator Juniper. This tree is very easily identified because its bark looks just like alligator skin! The alligator juniper has dark blue-green scaly leaves that exist in clustered wisps at the end of notched twigs. Animals enjoy eating the berries, and many bird species use the trees for mating and nesting.
  • Another conifer is the Apache Pine. This pine is rare in the United States, and usually only found in the sky islands. They are known for possessing extraordinarily long needles, often up to 10 inches (25 centimeters), and are finely adapted to low-intensity fire frequencies of less than five years.
  • The bobcat is a common predator in this biome. It is Arizona’s most common wild feline, outnumbering the mountain lion. They are medium-sized and have unique, speckled coats with a short, ‘bobbed’ tail. Their diet consists of rabbits, rats, and mice, but they are also known to attack larger game, such as deer. This is an animal whose numbers are decreasing because of human expansion into their habitat and hunting.
  • One of the largest animals is the mountain lion. The mountain lion is a top predator, preying on almost any animal below them in the food web, including fellow mountain lions, if they cross into their territory. They are known to stalk and ambush their prey, often from above. Like the bobcat, the mountain lion’s numbers are dwindling due to habitat destruction and human development.
 
Chiricahua National Monument isn’t defined as any one biome. Instead, it resembles five biomes, whereas most areas only characterize one! The biome characteristics frequently mix together to create a unique mosaic of environments and species. Many animals exist at all elevations in the park. All of the wildlife have adapted their bodies and/or behavior in order to thrive in the conditions of their home environment. The desert and grassland environments are near the park entrance. Around the visitor center is a deciduous forest-type environment. Near the highest elevation, there is some coniferous forest environment. If you keep your eyes open, you can see these characteristics nearly everywhere!

Last updated: December 7, 2018

Contact the Park

Mailing Address:

12856 E Rhyolite Creek Rd
Willcox, AZ 85643

Phone:

(520) 824-3560

Contact Us