That Tropical Feeling: Palms in the Desert

Living in the Sonoran desert can get a little dry at times, so one way we delude ourselves into feeling like we actually live in a tropical paradise or on the shores of a Caribbean beach is to plant palm trees. Our need for desert denial is so great that, next to the faux saguaro, one of the most common tech art designs for cell towers is a palm. But did you know that there is actually one species of palm that is native to Arizona and the Sonoran Desert?

The Desert Fan Palm (Washingtonia filifera) is a relict of more temperate days in these parts dating to as long as over six million years ago. Today, small wild groves are still tucked up in secluded canyons and near springs in the southwest where they have a reliable source of water. Just north of Phoenix, the privately owned Castle Hot Springs Resort includes natural springs that nurture a palm forest, as well as developed springs and carefully manicured groves. West of Phoenix at the KOFA National Wildlife Refuge, a small wild grove persists high up in a narrow shady canyon. Over in California, you can relax in the shade of native palm oases at Joshua Tree National Park.

Closer to home, all around us in the suburbs of Phoenix, our native palm is one of about two dozen species that have been introduced from all over the world for landscaping. One of the best places to view what most resembles a natural Desert Fan Palm grove is at the Phoenix Zoo, where the palms have developed massive “skirts” of dead fronds that surround the stout trunks. Groves in their natural, unpruned form are habitat for abundant wildlife, including a rare bat species, desert rats, lizards, snakes, many type of insects and birds, bighorn sheep and coyotes. Hooded Orioles use palm fibers to weave beautiful nests that hang in the protective shade of the leaves. For indigenous people, palm groves were a source of fiber that was woven into cloth and twined for cordage, leaves for making thatched roofs, walls and baskets, plus fruit and seeds for food.

Unfortunately, the benefits of palms for wildlife are not so endearing to many contemporary homeowners, who prefer not to welcome so many critters into their yards. Palm skirts are also regarded as a fire hazard, although in wild areas, occasional fire actually rejuvenates the groves by clearing out dense brush and creating fertile ground for new trees. Healthy mature palms are fire resistant, and will usually survive a wildfire.

Other notable palms in the suburbs are the majestic date palms, whose Latin name, Phoenix dactylifera, happens to include the name of our fair city. Date palms differ from fan palms in having long feather-shaped leaves, and also produce sweet succulent fruit. A relict of the commercial groves that were once abundant in the area is ASU’s Polytechnic Campus Date Palm Grove, which boasts over fifty different cultivars and is reputed to be the largest date palm collection of any public garden in the country. These palms represent a rich history of human civilization centered in the Middle East, where palms were critical to the development of early agricultural societies and highly valued for trade. The importance of date palms is recorded in drawings and temples of ancient peoples dating back to 7000 years ago. According to Islamic tradition, the original tree of life in the Garden of Eden is said to have been a date palm.

Bougainvillea: Tropical beauty in the Desert

From a naturalist’s perspective, one of the most striking things about the Phoenix suburbs is the lush green diversity of plants that thrive in our neighborhoods and parks. Compared with the surrounding desert, where plants depend on scanty seasonal precipitation, the suburban climate is subtropical, enhanced by irrigation and elevated humidity. Added to this, we have introduced hundreds of plant species from all over the world for our personal pleasure and agriculture: citrus fruits and roses from China, olives and rosemary from the Middle East, eucalyptus from Australia and aloes from Africa.

Perhaps one of the most dramatic flowering plants that grace the corridors of the Phoenix metro area is Bougainvillea, a tropical shrub introduced from rain forests of South America. In their native habitats, these sun-loving vines sprawl and climb over other shrubs and trees. Here they are usually planted and pruned to behave as shrubs or grown on walls and trellises. Enterprising horticulturalists have hybridized the fourteen native species in every possible combination to create over three hundred varieties that are now dispersed all over the planet. There is even a website called bougainvillea.com where you can order any color of the sunrise to grace your personal garden space. Beware, however, the flesh-ripping thorns that hide beneath the evergreen foliage! Fortunately, there are thornless options, but the most brilliant magenta Bougainvillea’s are inevitably the most fiercely armed.

These plants were named after Admiral Louis Antoine de Bougainville, who is well regarded in his homeland as the first Frenchman to lead a sailing expedition around the world between 1766 and 1769. In addition to having a spectacular tropical plant named in his honor, the admiral’s legacy includes several south Pacific islands, ports and straights, plus thirteen ships in the French navy that have celebrated his prestige on their transom. The circumnavigation was also historic for being the first to include professional naturalists, as well as the first woman known to sail around the world, as members of the ships’ crew. Historians still question the strange liaison between the expedition’s botanist, Philibert Commercon, and his valet, Jeanne Bare. The petite valet’s true identity as a woman was supposedly not known until the ships landed in Tahiti, where perceptive natives instantly recognized him as a her. Bougainville’s travelogue, Voyage Autour du Monde (Journey Around the World), was influential to philosophers and artists of the time who transformed his descriptions of Tahitian society into iconic images of the Noble Savage.

Parajo Carpinteros

If Del Webb were a bird, the corporation would surely be a woodpecker, also known in Spanish as parajo carpinteros, or carpenter birds. Community development is one of the side effects of woodpecker nest-building skills, as holes excavated by these industrious birds become homes for many other species. Woodpeckers build new nest holes every year, which ensures an ample and continuously replenished supply of housing for other cavity nesters, including kestrels, swallows, elf owls, flycatchers and starlings. Even bats, mice and lizards take advantage of abandoned holes in trees or saguaros in the desert.

Nest building begins mid-winter, especially for carpinteros that prefer saguaros. Several months are necessary for the inside of the nest cavity to cure or scab over before a mating pair will lay eggs inside. A cavity may have numerous ‘homeowners’ over the long life of the cactus. When the saguaro eventually dies, the hard-skinned cavity is one of the last parts to decay, leaving behind a gourd-like container called a saguaro ‘boot.’

Each of the four woodpeckers commonly seen around Phoenix suburbs are easily distinguished by size alone, ranging from the small (7.5”) black and white striped Ladder-backed Woodpecker to the extra-large (12.5”) orange-shafted Northern Flicker. In between are the medium sized (9.5”) Gila Woodpecker and the large (11”) yellow-shafted Gilded Flicker. Of these, the Gila Woodpecker is by far the most common, with hundreds being logged during area Christmas bird counts each year, relative to dozens of the other species. Local photographer Rick Halliburton caught this photo of a Gila foraging cranberries from his homemade suet.

Deem Hills Trails

After nearly forty years of collecting dust on the shelves of the City of Phoenix Parks and Recreation planning department, plans for multi-use trails in Deem Hills have finally become reality. Last spring, construction of over eight miles of trails began. Previously existing trails were widened to four feet and pristine terrain was excavated to create multiple loops that meander across every face of the hills. Trail access is conveniently located along 51st Avenue right next to the Deem Hills Recreational Park, where families can also enjoy picnicking, soccer and playground fun. There is a second trailhead on the northeast end of Deem Hills at the end of Pinnacle Vista Road. Hikers, bikers, runners and horseback riders in the area all agree that these are some of the best trails in north central Phoenix.

How to find the two official trailheads into Deem Hills:
**The main trailhead starts on the west end of the preserve at Deem Hills Recreation Area. To get there, drive north on 51st Ave. from Happy Valley Road. Turn right on West Deem Hills Parkway. Turn right into the Recreation Area. Look for the trailhead signs near the southeast corner of the parking lot.

**The Pinnacle Vista trailhead is located on the northeast side of Deem Hills. To get there, drive north on 33rd Ave. from Happy Valley Road. Turn left at Pinnacle Vista road and follow it for a mile to the end where it makes a sharp turn to the right. The parking lot is on the left just a couple hundred feet further up the road.



To download this PDF of the Deem Hills trail map, go to www.Phoenix.gov. You’ll find the map labeled Deem Hills Revised Master Plan in the Parks and Recreation section of the website. Or cut and paste this URL: http://phoenix.gov/PRL/deemmast.pdf

Frequent Flyers: Bats of Deem Hills

Go out for a stroll on any summer morning or evening, and you are likely to catch a glimpse of twilight’s most frequent flyers: bats. With superpowers far superior to those of their comic avatar, bats are some of the most diverse and abundant of Earth’s creatures. More than one out of five mammal species in the world are bats. Likewise, about 20% of the 138 mammal species in Arizona are bats, with twenty-eight kinds patrolling the night skies throughout the state, especially during the warmer months. Here on the urban fringe of Phoenix, about a dozen species are likely to flutter through while foraging.

While most of our leather-winged neighbors migrate south or hibernate during the cooler winter season, one species, the California Leaf-nosed Bat, is active year round in central Arizona. More drought and cold tolerant than other bat species, they are also well adapted to life in the desert suburbs. The California Leaf-nose is more common in neighborhoods close to natural open space like the Deem Hills, where they can find refuge in cliff crevices and old mine tunnels.

Unlike most other desert bats, the Leaf-nose is an expert at hunting ground dwelling insects and other prey, relying mostly on their excellent eyesight and stellar sense of hearing. Combined with their sixth sense of echolocation, which is augmented by their leaf-like nose flap and extra large ears, these bats can swoop down and snatch a caterpillar resting on a shrub or grab an unsuspecting beetle wandering across the desert, with laser-like precision. During the summer months, they forage mostly by night, but in the winter, it is not uncommon to see them hunting in warmer daytime hours when their prey is also most active.

Two close relatives of the California Leaf-nose, the Lesser Long-nose and Mexican Long-tongued bats, are important pollinators for agaves, saguaros and other cacti. They both have extra-long tongues, longer noses and smaller ears than their cousin, adaptations that make it easier for to them lap up nectar. Flowers of bat-pollinated plants are usually large, tubular, bright white and bloom at night, attracting bats and other night-flying visitors. While these two bat species are abundant in more southern regions of the Sonoran desert, they rarely make it this far north, where saguaros rely on many species of insects and birds for pollination. The Lesser Long-nose bat is currently listed as a federally endangered species.

Bats are fun to see in the wild, but if you don’t want to share your home with bats, be sure to seal all openings in your roof and attic with fine meshed screens. The best time to bat-proof your home is in the fall or winter when most bats migrate south or leave dwellings to hibernate in the wild.

All bats are protected by state laws; it is illegal to hunt, capture, harm or kill a bat. To help protect bats, stay away from mine tunnels and natural caves where they hang out. For lots more information on Arizona’s bats, check out these on-line bat sources:
Arizona Fish and Game Department www.azgfd.gov
Western Bat Working Group www.wbwg.org

"Other Species"

“CAUTION: You are in a natural habitat! Rattlesnakes and other species may be present.”

For many people, the mere idea of a snake elicits a reaction of fear. Attach a rattle to that idea, and that fear escalates to sheer terror. In response to these raw emotions, warning signs like this have been posted in some city parks and preserves. Casting aside a rational discussion about “caution,” “natural habitats,” and “other species,” this article aims to honor some of the non-rattle bearing species of snakes that you might encounter near Deem Hills.

Arizona is home to fifty-two species of snakes, thirty-eight of which are non-venomous or only mildly so. Venomous or not, snakes are much like humans in that their primary interests are food and finding a mate. Unlike us, our local serpents are normally not aggressive towards anything bigger than what they can eat. Since humans are much too large to waste venom on or to wrestle with, their natural instinct is to escape when they see one of us. Of the non-venomous species, about sixteen kinds may be found in natural areas and adjacent developed neighborhoods around north Phoenix.

If you see a snake, you can safely stand close enough to quietly observe characteristics that you need to identify what species you have the fortune to cross paths with. Head shape, skin color, pattern and texture, body length, shape of pupils, habitat, and whether the skin is shiny or matte are all useful indicators to notice. The time of day is also important, because many snakes are strictly nocturnal, so are very rarely seen during the day unless they were unfortunate to become roadkill. During the hottest summer months, desert snakes are primarily nocturnal, but most snakes hibernate underground during the cooler months between November and March.


Of the twenty or so species that you are most likely to see on the north suburban fringe of Phoenix, including the rattlers and coral snake, only seven species are commonly active both day and night during warm seasons. These are the Western Diamondback, Mohave Rattler, Ground Snake, Gopher Snake, Western Patch-nosed, Red Racer, and Black-necked Garter Snake.

By far the most frequently encountered of our “other species” are Gopher Snakes, one of the most widespread and abundant serpents not only in Arizona, but continent wide. They live in almost every habitat in Arizona including urban areas, but excluding alpine tundra. Gopher Snakes are often mistaken for their venomous cousins, because their scale patterns and color are so similar to some rattlesnake species, and even have black and white stripes that resemble the tail of a diamondback. Their scales are also keeled rather than smooth, and have a matte finish like a rattler. Distinctive differences are at both ends of the Gopher Snake. A good look at the tip of the tail (no rattle) and head (slender, not bulky and triangular) should set your mind at ease. If you can see their eyeballs, you might also notice that Gophers have round black pupils rather than vertical pupils like the rattlers. Gopher Snakes grow huge, up to nine feet long, which can be alarming, but we are way too big for them to eat, so rest assured that these slender beasts would not try to constrict and try to swallow a human or your dog.


Like many snake species, Gopher Snakes make excellent pest control, that is, if you don’t consider them to be a pest. They’ll eat rats, mice and ground squirrels, as well as the occasional rattlesnake and its eggs. Many other snake species eat termites, scorpions, spiders and centipedes, some of the common desert critters around home that we tend to have negative reactions to.

If you see a snake of any kind, the best plan of action is to leave it alone and walk away. Most likely, it will slither away to safety, as they know that we are far more dangerous to them than they are to us. Homeowners in Stetson Hills who wish to have any type of snake removed from their property can call neighborhood herpetologist Mark Russell at 602-315-7978, who will gladly come to your home to capture and relocate the snake.

An excellent resource for more information on snakes is “A Field Guide to Amphibians and Reptiles in Arizona “by T.C. Brennan and A.T. Holycross. An expanded version of the guide is also found on-line at www.reptilesofaz.org.

Gopher Snake photos courtesy of Rick Halliburton.

Verdins: Avian Architects of the Desert

Photo by Richard Halliburton

One amenity you may have on your list of considerations when buying or building a new home is energy efficient construction. Long before the notion of passive solar architecture emerged in modern lexicon, one of our local avian architects, the Verdin, has been creating “green” housing for centuries, if not millenia. No, they haven’t figured out how to install solar panels, but these birds do utilize the most important components of passive solar strategies: site selection, structural orientation and insulation.

Unlike most birds, Verdins build nests year round. During the breeding season, between March and June, nests are used to protect eggs and rear their young. The rest of the year, they are used as shelters from the weather. Depending on the season, the nest will be built in a location that is best suited for keeping warm or cool. In winter months, a south-facing sunny location is chosen, with the entrance oriented away from prevailing winds to keep warm. During warmer months, they will move to a north-facing shady area with the entrance oriented towards cooling winds. The amount of insulation can also be adjusted by type and thickness to suit the season.


Working together, mating pairs build hollow oval-shaped homes about the size of a cantaloupe. Males build the outer shell using thorny twigs and grasses. Females take care of interior design, lining the nest with a soft inner layer of leaves, feathers, fur and spider-webbing. Usually the nest is attached among the outer branches of a large tree or shrub with an easy flight path to the entrance. Look closely at one of these balls of sticks, and you’ll see a small hole near the bottom of the nest. Verdins prefer to build along washes where food is more abundant, but are also common in landscaped suburban neighborhoods. A busy pair may build more than ten nests over the course of a year!

You are more likely to notice a Verdin nest than the actual bird, even though they are among the top ten most abundant species in annual regional bird censuses in the Sonoran desert. On a typical sunny morning, the loud whistles and chirps of Verdins are some of the dominant bird calls echoing across washes and green belts around Deem Hills. If you follow your ears to find the song’s source, you might be amazed to see how tiny they are, less than five inches long with a wing span just over six inches.

If you’ve never noticed them, that is not surprising, since Verdins are also listed in Sibley’s Guide to Birds as one of the eight “Drab Gray Birds of the Arid Southwest.” Of all the DGB’s, however, adult Verdins are one of easiest to recognize, since the heads of both males and females look like they have been dipped in greenish yellow paint. The juveniles are the drab ones, being dull gray all over. In Spanish, verdin (pronounced “ver-deen”) means “green stain” or “green pond scum.” Not a very flattering description, but apparently that is what some early desert ornithologist was reminded of! A closer look will reveal rusty red shoulder patches. When not tending nests, Verdins spend their days flitting about in trees and shrubs, pecking at seed pods, fruits, flowers or branches to glean insects, spiders, seeds, berries and nectar.

If you are lucky enough to have a Verdin build its nest near you, let it be an inspiration to make your own home more energy efficient and perhaps a little more comfortable!