The Sonoran Desert is the region extending from Southwestern portions of the United states (Arizona & California) through the northwestern states of Mexico, including Sonora, Baja California, and Baja California Sur. This region is known for its biodiversity and unique biomes, including tundras, coniferous forests, deciduous forests, desert, grasslands, and riparian habitats.
At the Coalition, we focus our work in Pima County in southern Arizona, which overlaps with the Sonoran Desert and Madrean Archipelago Ecoregions (otherwise known as the Madrean Sky Islands).
The Madrean Archipelago Ecoregion is a region of basin-and-range topography that spans parts of southeastern Arizona and southwestern New Mexico. They are called “Sky Islands” because of the significant differences between the forested mountains at the top and the desert low-land foothills at the base and in the valleys in between. Many plants and animals that live in the Sky Islands are endemic to their region and could not survive anywhere else. These areas are so unique because of the vast amount of biodiversity that exists in just a few miles.
It is worth noting that although the boundaries in the map above are helpful to give context to the region, the Sonoran Desert doesn’t end like a hard line on a map. At the edge, the habitat blends into the surrounding landscape and is influenced by its surrounding biotic communities, creating transition zones.
Weather and climate
The Sonoran Desert is unique in many ways, including its wide range of climates and extreme weather conditions. It is considered the wettest desert in the world and has two rainy seasons – one in the summer, often called monsoon season, and one in the winter. The hottest and driest part of the Sonoran Desert is near the lower Colorado River, where summer temperatures can reach more than 120 °F (48.5 °C) and annual rainfall is less than three inches.1The cooler and wetter areas of the Sonoran Desert are in higher elevations or along mountain ranges.
Sonoran Desert Scenery
This is what winter looks like in the desert!
Sonoran Desert Flora and Fauna
The Sonoran Desert is considered the most biodiverse desert in the world. This biodiversity is in part attributed to the wide range of climates within the Sonoran Desert and the unique adaptations that allow populations to thrive. All life here has evolved to make the most of the water available and conserve as much as possible.
The Sonoran Desert is home to at least 60 different species of mammals, more than 350 bird species, and over 100 reptiles.2 One thing many of these animals have in common is that they are masters of water conservation. For example, the Sonoran Desert tortoise can live for a year without drinking water due to how it stores water in its body weight.3
Many animals here are nocturnal or most active at dawn and dusk to avoid the heat. These animals spend the days in the cool shelter of their burrows or nests and come out when it’s cooler to eat or to hunt. This includes the cactus ferruginous pygmy owl, javelinas, coyotes, mule deer, and many insects, such as hairy desert scorpions, Sonoran Desert tarantulas, and giant desert centipedes.
Photo by Jessica Moreno
Mule deer doe trio exploring a Sonoran Desert shrub land.
Plant Community Details:
Jojoba bush, palo verde, prickly pear, creosote, saguaro, cholla, brittle bush, barrel cactus.
There are over 2,000 species of native plants in the Sonoran Desert.4 Desert shrubs, trees, berry bushes, cacti, wildflowers and grasses can all be found here. The most common plants include barrel cacti, prickly pears, chollas, creosote bushes, palo verde trees, mesquite trees, ocotillos, yuccas, and the famous Saguaro cactus.
These plants are well adapted to their desert climate and conserve their water in many ways, including having small leaves, deep roots or shallow roots that spread far, and some can photosynthesize through their bark, like the palo verde and ocotillo. This allows them to decrease water loss even further. This region is well known for its cacti, who store lots of water in their succulent flesh.
Photo by Richard Trible
Photo by Claire Letourneaux
Sonoran Desert Abundance and Land Acknowledgement
The abundance of life here is attributed to the many resources available provided by plants. These plants have provided food, shelter and resources for people and animals living here for thousands of years. Many trees here, including mesquites, ironwoods, and paloverdes are leguminous trees, meaning they are in the pea family. If they soak up enough water during winter, they will flower in the spring and grow seed pods shortly after.
Cactus fruits, especially from saguaros, prickly pears, and barrel cactus, provide sugar, water and vitamins to animals and are plentiful in the summer. Other fruits are available too, mostly in the fall, such as wolfberries and hack berries.
Photo courtesy of Pima County
Humans have contributed a lot to this diversity of plants; the indigenous people of the Sonoran Desert have cultivated and domesticated plants here and stewarded the land since time immemorial.5 Peoples of the Hohokam culture were early inhabitants of the Sonoran Desert. Descendents of the Hohokam, including the Tohono (desert) O’odham, Pascua Yaqui, and Akimel (river) O’odham, have a rich history and have prospered in the Sonoran Desert for generations.6
We are so lucky to live in a place with such incredible biodiversity. It is a gift to experience the Sonoran Desert, from the desert scrub lands, to the alpine forests. This is our home too. At the Coalition for Sonoran Desert Protection, we vow to continue our important work of defending and protecting the biodiversity of the Sonoran Desert in southern Arizona through environmental advocacy, community science projects and education, and collaboration with others.
Recommended Field Guides and Resources – Check out our Bookshop page!
More Resources:
Sonoran Desert – Sonoran Desert Region (desertmuseum.org)
Living with Wildlife – Arizona Game & Fish Department (azgfd.com)
The Sky Islands – Sky Island Alliance
References
- Sonoran Desert – Sonoran Desert Region (desertmuseum.org) ↩︎
- Sonoran Desert (biologicaldiversity.org) ↩︎
- Sage of the Sonora | U.S. Fish & Wildlife Service (fws.gov) ↩︎
- Sonoran Desert Network Ecosystems (U.S. National Park Service) (nps.gov) ↩︎
- Genus Opuntia (incl. Cylindropuntia, Grusonia, and Corynopuntia) (desertmuseum.org) ↩︎
- Native Peoples of the Sonoran Desert: The O’odham (U.S. National Park Service) (nps.gov) ↩︎