SONORAN DESERT

The breeding range of the desert Purple Martin lies in the heart of the Sonoran Desert and reaches the extreme southwest of Arizona, northwest Mexico, and Baja California.

SUMMER

June – August

Intense heat, some animals are nocturnal to avoid heat.

Monsoon Season, July – September

Sudden rainfall, dormant seeds awaken, temporary abundance.

FALL

September – November

Cooler transition, plants set seeds, wildlife prepares for winter.

WINTER

December – February

Cooler temperatures with occasional rain showers; some plants bloom

SPRING

March – May

Temperatures rise, wildflowers bloom, animals become active.

The Sonoran Desert and The Saguaros

Seasonality

The seasons place an important driver for biodiversity in the Sonoran desert. Saguaros themselves have an annual schedule in rhythm with the changing seasons.

The Life History of a Saguaro

Saguaros are slow growing plants, but they can live to be 300 years old. It can take them 35 years to grow their first flowers, 70 years to grow their first arms, and 80 years or more to reach the size required to support cavity-nesting birds.

Where do Saguaros Live?

Saguaros have a relatively small range, only existing in Arizona, north western Mexico, and a tiny corner of California. Since saguaros are not a frost tolerant species their range to the north is limited by temperature. Saguaros also require areas that receive regular summer monsoon rains.

Adaptation to the Desert

The Sonoran Desert is very dry most of the year, but receives excessive rainfall during the monsoon season. Saguaros have adapted to this seasonal rainfall by evolving water storage capacity that they can use during the dry season.

Adaptation to the Desert

The saguaro has pleats that expand like an accordion when the water is being absorbed and contract when water is used during the dry season.

Recruitment

It takes 2 good consecutive monsoon seasons and 1 wet winter for new saguaros to germinate, which happens about once every 20 years

This poses huge threats for saguaros and other native wildlife which are now exposed to fires that are hotter and more frequent than ever before

The Sonoran Desert and The Saguaros

Seasonality

The seasons place an important driver for biodiversity in the Sonoran desert. Saguaros themselves have an annual schedule in rhythm with the changing seasons.

The Life History of a Saguaro

Where do Saguaros Live?

Adaptation to the Desert

The Sonoran Desert is very dry most of the year, but receives excessive rainfall during the monsoon season (which is roughly June to September). Saguaros have adapted to this seasonal rainfall by evolving water storage capacity that they can use during the dry season. The saguaro has pleats that expand like an accordion when the water is being absorbed and contract when water is used during the dry season.

Recruitment

It takes 2 good consecutive monsoon seasons and 1 wet winter for new saguaros to germinate, which happens about once every 20 years

Wildfires have always occurred in the Sonoran Desert, but they used to be small and short-lived since there weren’t many plants to fuel the fires. This has changed with the emergence of invasive grasses, which have quickly spread and created a dense mat of fuel for wildfires. This poses huge threats for saguaros and other native wildlife which are now exposed to fires that are hotter and more frequent than ever before

The Sonoran Desert Wildlife

Round-tailed Ground Squirrel

Round-tailed Ground Squirrels mostly live communally in desert scrub, but can also be found in urban areas. They require areas that have deep soils so they are able to create their burrows which can be 3 feet deep. They eat all types of plant material including seeds, leaves and flowers. They will also eat insects and carrion if it is available. Photo: Dan Weisz

Mojave Rattlesnake

Mojave Rattlesnakes can be found in desert scrub and semi desert grasslands. They eat all types of small animals including mice, rats, lizards, birds, and frogs. Mojave Rattlesnakes are venomous but will usually not bite humans as long if they are left alone. Photo: Dan Weisz

Javelina

Javelinas, also known as Collared Peccaries, look very similar to wild boars, but are genetically different and much smaller. They can be found in the desert and oak woodlands living in family groups. Javelinas typically eat plants such as agave, mesquite beans, roots, and prickly pear cactus. They can also eat lizards, dead birds, and rodents if they are available. Photo: Dan Weisz

Arizona Blonde Tarantula

Arizona Blonde Tarantulas live in saguaro-dominated habitats. Their diet consists of insects, other arachnids, and lizards. To temporarily stun their prey, they use a mild venom that is not harmful to humans. Arizona Blonde Tarantulas also have defensive hairs that can be irritating to the skin. They are sometimes kept as pets due to their docile nature. Photo: Dan Weisz

Coyote

Coyotes are one of the most resilient mammals in the Sonoran Desert. They can be found in many types of habitats including desert scrub, grasslands, and urban areas. Coyotes are also adaptive hunters, and can hunt larger prey in groups or hunt small prey individually. During the summer, a large portion of their diet includes saguaro and prickly pear fruit. Photo: Dan Weisz

Bobcat

In the Sonoran Desert, bobcats prefer rocky areas with abundant plant cover, but they can also inhabit woodlands, grasslands, and urban areas. Their diet consists of small animals including rodents, lizards, birds, and snakes. They have also been known to kill deer and eat carrion. Photo: Dan Weisz