Observant hikers on Phoenix desert preserve will quickly notice skittering lizards, zipping hummingbirds and the occasional snake that call the desert home. Chuckwallas are large bodied lizards that bask throughout the hottest summer months and wedge themselves into cracks when they feel threatened. Rattlesnakes and bullsnakes often emerge in the early morning or early evening during warm months and should be enjoyed from a distance.
Below we've listed some of the most common desert critters found in Phoenix desert preserves. Remember, the preserve is their home, and when visiting, please enjoy their beauty from a safe, courteous distance. It is unlawful to move, touch, harm, or remove any wildlife from the preserves at any time.
The Desert Tortoise is an herbivore that may attain a length of 9 to 15 inches in upper shell length. At least 95 percent of its life is spent in burrows. There it is also protected from freezing while dormant from November through early spring. They eat primarily herbs, grasses, shrubs, cacti, and flowers. Ravens, Gila Monsters, Foxes, Roadrunners and Coyotes are all natural predators of the Desert Tortoise. This handsome specimen shown at right was seen lumbering along a roadside in South Mountain Park. (Click on image to enlarge detail)
Chuckwallas call all Phoenix preserves home, but South Mountain Park is notable for its chuckwalla population. With an average of 65 chuckwallas per hectare, South Mountain has among the highest density of chuckwallas in the Sonoran Desert. And South Mountain chuckwallas are like none other -- they exhibit a “carrot tail” phenotype, which is unique to this population. Strictly herbivorous, the Chuckwalla reptile eats fruit, leaves, buds and flowers. When the Chuckwalla senses danger, it scurries between rocks and lodges itself tightly in crevices by inflating itself. They have a thick blunt tail, and grow 11 to 18 inches long. These lizards emerge in the morning and bask in the sun until it reaches its optimum body temperature of 100 to 105 degrees.
(Click on image to enlarge detail)
Venomous! Speckled rattlesnakes are common in Phoenix preserves and other parts of the valley adjacent to similar rocky hillside habitat. They are highly variable in color, from a white/grey in the South Mountain and White Tanks areas, brown in North Phoenix, and orange and red going North into Cave Creek and the Anthem areas. They have a loosely banded pattern that is highly flecked to resemble granite. The Southwestern Speckled Rattlesnake is a medium sized snake, normally around 3 feet long, but has been known to exceed 4 feet. (Click on image to enlarge detail)
Seldom seen but of great importance are the numerous bat species that live among the desert cliffs and caves of our mountain parks. Bats are a key pollinator of the saguaro cactus and other night blooming plants. They favor nectar, pollen, flowers and fruit from agave and other cacti, especially saguaro. They can be observed during dusk and returning to their roosts in the early morning.
(Click on image to enlarge detail)
Western Diamondback Rattlesnake
The Western Diamondback Rattlesnake, which can exceed 7 feet in length, is the king of Southwestern desert rattlers. Its basic color ranges from brown to gray to pinkish. Its back is lined with dark diamond-shaped blotches outlined by lighter-colored scales. Its tail is circled by several alternating black and white bands. This snake takes up residence among communities of small mammals such as rabbits, ground squirrels, mice and rats; usually hunting at night. The Western Diamondback, especially the juvenile, often comes under attack itself. It may become a meal for an eagle, a hawk, roadrunner, kingsnake or whipsnake, coyote, or fox. (Click on the Diamondback image to enlarge)
References & Related Links:
Arizona Game and Fish
Reptiles of Arizona
International Journal of Organic Evolution: Kwiatkowski M.A, and Sullivan B.K. 2002. Geographic Variation in Sexual Selection Among Populations of an Iguanid Lizard, Sauromalus Obesus. Evolution 56(10): 2039-2051.Author Information:
1 Department of Biology, Arizona State University, Tempe, Arizona 85287-1501
2 Department of Life Sciences, Arizona State University West, 4701 West Thunderbird Road, Glendale, Arizona 85306
Common Snakes of the Phoenix Area,
Arizona Office of Tourism Guide http://www.arizonaguide.com/things-to-do/nature/birding-wildlife/arizona-wildlife-viewing
Arizona-Sonoran Desert Museum
Spring 2013 Wildflower Update
With sufficient fall and winter rains, after a healthy summer monsoon, wildflower blooms in the Phoenix Desert Preserves will be the best they've been in many years. As a general rule look to north facing slopes, which are free of the most direct sunlight, for the best wildflower growth.
Below, we've listed recommendations from our park rangers on some Phoenix Desert Preserve areas that historically boast impressive waves of wildflower growth. Scroll to the bottom for a photo guide of some of the most common wildflowers blooming this spring.
South Mountain Park/Preserve
Areas in the preserve with good wildflower displays include the Bajada, Las Lomitas, Ranger, Kiwanis accessible from the Central Avenue entrance (please note road restrictions at the Central Avenue entrance); and the Pima Canyon, and Beverly Canyon areas located in the eastern end of the park. The roadway leading to the Gila Valley overlook (Central Avenue entrance) also offers good wildflower growth. North facing slopes in the Pima Canyon and Beverly Canyon (Javelina Trail) entrances of the park also are a great spot for wildflowers.
Many north-facing slopes on trails from the Desert Vista Trail trailhead parking area offer impressive wildflower blooms, including areas along the Desert Tortoise and Verde trails, both accessible from the main trailhead parking area.
Piestewa Peak Area
Trail 8, the Quartz Ridge Trail, typically runs through impressive blooms. The trailhead is at
40th Street south of Shea Boulevard. Several trails with north-facing slopes around Piestewa Peak that are accessible from the Phoenix Mountains Park and Recreation Area also are good spots for wildflower viewing. The Summit Trail typically does NOT offer good wildflower viewing.
Hillsides and washes surrounding Trail 100 out of the Dreamy Draw trailhead at Northern Avenue and Highway 51 often are covered in a wide variety of wildflower blooms.
Trees and Plants
Saguaro is the keystone plant and icon of the Sonoran Desert. This slow growing columnar cactus is this country's largest cactus, often reaching between 40 and 60 feet in height and weighing (when fully hydrated) approximately 80lbs per foot. A mature Saguaro may weigh as much as 8 tons. They can live for more than 200 years. The State Flower: Saguaro flowers are formed on the growing tips, and following pollination, fruits will form, each containing approximately 2000 seeds. Dispersal, rainfall, and other factors result in only about one mature plant per 40 million seeds. ^ ^^
Palo Verde tree
In 1954, the State of Arizona named the Palo Verde as its State Tree. The legislature did not distinguish between the two species of this tree (the foothills and the blue) that are native to the State; therefore both the Foothill and the Blue share the honor. Both the Blue and Foothill Palo Verdes have a number of characteristics in common, starting with the reason they are called Palo Verdes (Spanish for green stick). Palo Verdes serve as the nurse plants for the saguaro, giving shade and protection to seedlings in their slow growth to becoming giants. Plant diversity encourages diversity of animals attracted to the food, shelter, and nesting sites provided by Palo Verde trees. ^^^^ ^^^^^
Teddy Bear, or Jumping Cholla
Have an upright trunk with closely spaced horizontal branches near the top of the trunk. The stems are protected by a dense covering of yellowish spines which makes this cactus look soft from a distance, hence the common name Teddy Bear. This covering of spines not only provides protection from herbivores like rabbits and rodents, it also is believed to protect the stems from intense sunlight and may be a cooling mechanism for the cactus. The spines are very sharp and well barbed. Younger spines are yellowish and turn black with age. Yellow-green flowers emerge at the tips of the stems in spring, and the fruits that follow usually have no viable seed. The segments of the Teddy Bear Cholla are easily detached from the plant by a soft touch of a passing animal or human, or even by strong winds. Many people might swear that the cactus jumped at them and grabbed them, which explains the common name, Jumping Cholla. ^ ^^^^^^ (Click Cholla image to view larger)
Medium to large sized shrubs. Often several seemingly distinct shrubs will be growing together in a ring 6 to 20 m in diameter. This represents a clone of an original plant that may have been growing continuously for thousands of years. Small compound leaves are shiny, resinous, and dark green when young but can remain on shrubs for extended periods turning almost brown but still viable. The resin odor is at once acrid to deter plant eaters and yet pungently pleasant. The whole desert takes on this heavenly aroma after a rain shower signaling a return of life and verdance. No thorns. Yellow flowers with five petals appear generously in spring and at almost any other time of year following periods of generous rainfall. ^^^^^
Triangle-leaf bursage is a densely-branched subshrub to about 2 feet (0.6 m) tall with triangular, finely toothed, gray-green leaves. The leaves are lost in very dry periods. Though it can be confused with brittlebush when not in flower; this bursage is a smaller plant with smaller, duller gray leaves. It flowers from late winter into spring, with burs ripening in late spring. Triangle-leaf bursage has small, 1/4 inch wide yellow-green flowers without petals. They grow in pairs from the end of growth spikes and flower from February to July. Bursage gets its name from its burr-like seeds. The round seeds are covered with hook-tipped spines that attach themselves to the fur of passing animals. The plants produce many seeds after both summer and winter rains. Triangle Leaf Bursage is a member of the ragweed family. It is native to the Sonoran desert and is one of the most commonly encountered plants in South Mountain and McDowell Mountain Parks.
Desert Globe Mallow
Globe Mallow is a perennial native to the Sonoran Desert. This resilient plant is shaped like a rounded shrub and can survive in temperatures from 5 degrees and up. To live it requires full sun and as a result can grow very fast, up to 3 feet tall and 3 feet wide. As an Evergreen it has a gray/green color and a coarse texture. Its flowers bloom in spring and can be orange, white, pink or lavender. Be careful when touching while hiking in Phoenix, it has no thorns but can irritate skin and eyes. ^^^^^ (Click to enlarge this Globe Mallow found on the Mormon Trail in South Mountain Park)
Brittlebush is a medium-sized rounded shrub. Plants grow 2-5 feet high. It has long, oval, silver-gray leaves that are somewhat fuzzy. The branches are brittle and woody, and contain a fragrant resin. In the late winter and early spring small yellow flowers form on long stalks well above the leafy stems. The hairs on the brittlebush plant serve several purposes. Many desert plants have hairy leaves or stems. The hairs act like a blanket over the leaves to protect them from the heat and cold. The white color reflects the sunlight helping to keep the plant cool. They also help trap any moisture and reduce the amount of water lost. ^^^ ^^^^^ (Click on image of Brittlebrush to see the details)
References and Links
^ National Park Service http://www.nps.gov/grca/naturescience/plants.htm
^^ Arizona-Sonora Desert Museum http://www.desertmuseum.org/visit/
^^^ Arizona Naturalist http://arizonensis.org/sonoran/fieldguide/plantae/encelia_far.html
^^^^ DesertUSA http://www.desertusa.com/mag01/aug/papr/palov.html
^^^^^ Sonoran Desert Naturalist http://www.arizonensis.org/sonoran/places/southmountain.html#Shrubs
^^^^^^ The Living Desert http://www.livingdesert.org/desert_plants_page.html?latin_name=Cylindropuntia+bigelovii
The most famous bird in the Sonoran Desert and our largest cuckoo, this bird is characterized by a long tail, streaked appearance, frequently erected shaggy crest, and a blue and orange bare patch of skin behind the eyes. It is capable of running very rapidly across the ground (15 mph) and rarely flies. However clown like it may appear to human eyes, the Roadrunner is a very effective predator. Its speed on foot is not just for show: it captures not only snakes and large insects, but also fast-running lizards, rodents, and various small birds. Often it seems curiously unafraid of humans. Trotting up close to peer at us, raising and lowering its mop of a shaggy crest, flipping its long tail about expressively, it looks undeniably zany. It comes as no surprise to learn that the Roadrunner is a member of the cuckoo family. Like all cuckoos, the Roadrunner is a zygodactyl bird (it has 2 toes pointing forward and 2 toes backward).^^ ^^^^^
(to see close-up of the Roadrunner above click on the image)
Great Horned Owl
With its long, earlike tufts, intimidating yellow-eyed stare, and deep hooting voice, the Great Horned Owl is the quintessential owl of storybooks. This powerful predator can take down birds and mammals even larger than itself, but it also dines on daintier fare such as tiny scorpions, mice, and frogs. A large, thick-bodied owl with two prominent feathered tufts on the head, the wings are broad and rounded. In flight, the rounded head and short bill combine to create a blunt-headed silhouette. ^^ ^^^^ (click on the image at left to see this Great Horned Owl parent with an owlet in nest perched in a saguaro in the Sonoran Preserve)
The Cactus Wren has a dull rusty colored crown, streaked back, heavily spotted breast, with tawny colored sides and belly; wing and tail feathers are barred black and white. The Cactus Wren primarily eats insects, including ants, beetles, grasshoppers, and wasps. Occasionally, it will eat seeds and fruits. The Cactus Wren has been the state bird of Arizona since 1931. ^^ ^^^^
(click on the image at left to seen an enlarged image of a Cactus Wren seen fluffing itself on a fence post in South Mountain Park)
Gambel's Quail are pear shaped birds with short legs and roundish wings. They eat seeds of grasses, shrubs, trees, and cacti as well as fruits and berries. They are ground feeders, generally seeking food in the morning and afternoon. These birds often join together in groups known as coveys, which may total 20 or more individuals in fall and winter. Natural predators include bobcats, hawks, rats, king snakes, and coach whips. ^^^^^
(to see details of a Gambel's Quail in flight and up close- click on images above)
Mature adults are medium-sized to large hawk. Dark overall. White rump and under tail. White tip to dark tail. Chestnut-red thighs and shoulders. Legs and bare face skin yellow. A handsome hawk of the arid Southwest, the Harris's Hawk hunts cooperatively in pairs or trios. The hawks surround their prey, flush it for another to catch, or take turns chasing it. ^^ ^^^^^
(Click to enlarge image at left for up close detail)
The Sonoran Desert would have a very different sound if it were not for the doves. The cooing songs of four species are among the classic bird voices here for much of the year. Mourning Doves are among the most numerous birds in the desert year-round. Other common doves include White-winged Dove, Common Ground-Dove, and Inca Dove. Dove nests are haphazard platforms of sticks, so flimsy that the eggs or young sometimes fall through them; as if to make up for this, the birds may make repeated nesting attempts, raising several broods per year. Doves love water, and it is only through their strong powers of flight that they are able to thrive in the desert; they may fly long distances to get to reliable sources of water. Flocks of doves hurtling overhead are a characteristic sight on desert evenings. ^^^^ ^^^^^^ (Click to see detail of this mourning dove foraging freshly sprouted seeds at Phoenix' South Mountain Park)
To Gila Woodpeckers, saguaros serve in place of trees: these woodpeckers go hitching their way up the sides of the giant cactus, and give voice to strident calls when they reach the top. The holes that they excavate for nesting sites, which may riddle the arms of some ancient saguaros remain to serve as natural birdhouses for a variety of other birds. In the desert, these birds must be resourceful. Gila Woodpeckers eat cactus fruits, mistletoe berries, and many other items in addition to insects. Highly adaptable, they make themselves at home in southwestern U.S. cities, where they will visit hummingbird feeders and steal dog food from back porches. They also have been known to make themselves unpopular at dawn by hammering out brash wake-up calls on metal pipes and other echoing objects. ^^^^^(Click on image to enlarge the detail of this hummingbird feeder ant thief)
Arizona is unique for its large number of different hummingbirds! Costas Hummingbird is the only true desert hummer here, but several others live along the desert's edges. Black-chinned and Broad-billed Hummingbirds nest in streamside woods in summer, while Anna's Hummingbird, a recent invader from California, nests in the same areas (and in residential neighborhoods) in winter. Our region hosts the greatest variety of hummers in late summer, when several species are on their way south. Rufous Hummingbirds, southbound from nesting grounds in the northwest U.S., may appear in the Sonoran Desert by July, along with lesser numbers of other species, to joust for space around the blooms that follow the summer rains.
The "flame-throated" Anna's hummingbirds are iridescent green above and grey below. In addition, the male's throat and forehead iridescent crimson rose in good light; in poor light, these areas appear to be velvety black. The females generally lack these iridescent rosy patches, but may have a few rose feathers on the throat. ^^^^^^^ (click on the Anna's hummingbird at right for a close-up view of this hovering little desert gem)
Another "flame-throated" hummingbird, the Costa's hummingbird is iridescent green above and grayish white below. The males in good light have an iridescent amethyst purple forehead and throat. The iridescent throat patch extends into an elongated "mustache." In poor light, these patches appear velvety black. The female completely lacks these patches. A desert hummingbird, Costa's breed in the Sonoran and Mojave Deserts of California and Arizona. It departs the desert in the hottest days of summer, moving to chaparral, scrub, or woodland habitat. ^^^^^^
(Click to see a close-up of the iridescent amethyst purple of the Costa's head and throat)
* Listing of Arizona Hummingbirds according to the Southeastern Arizona Bird Observatory:
References and Related Links:
^ Maricopa Audubon Society
^^ Audubon Society
^^^ Sonoran Audubon Society
^^^^ Southeastern Arizona Bird Observatory www.sabo.org
^^^^^Arizona Naturalist Common Sonoran Desert Birds
^^^^^^Sonoran Desert Naturalist