Wednesday, December 9, 2009

The Deer of Deer Valley

Have you ever wondered when the last time was that anyone saw a deer in Deer Valley? Or where there are deer nearby today? Or even, come to think of it, what is Deer Valley and why was it so named?

The icon that graces some of the local street signs and school district letterheads comes from a petroglyph hammered into boulders at Deer Valley Rock Art Center in Hedgepeth Hills, just two miles south of Deem Hills. Best viewed in early morning light, the one foot high by two foot wide glyph of two sparring bucks glows soft orange against the dark basalt rock. This is the true origin of the modern name, Deer Valley, for though there were certainly deer here up to fifty years ago, there is no reason to believe that they were any more abundant here than in other nearby areas. The vast petroglyph site, however, is very unique.

For reasons that archaeologists do not fully understand, people chose to mark their passing at Hedgepeth Hills for thousands of years, including about a hundred petroglyphs (out of over 1500) that appear to be renderings of game animals. For the various tribes of ancient people who lived around Deer Valley for over ten thousand years, Skunk Creek was likely an important traveling route, and was also a lush riparian corridor running free from its source in the hills north of the town of Anthem, to its confluence with New River near 73rd Ave. and Greenway. The summit of Hedgepeth Hills, which rise from near the banks of Skunk Creek was probably an excellent spot to survey the creek and surrounding landscape for deer.

With Skunk Creek passing just east of Deem Hills, it is likely that small herds used to wander through, perhaps as recently as fifty years ago, before the area was devoured by suburbs. Although the modern Deer Valley, which spans from the CAP canal to Greenway and east to west between 20th Street and 51st Avenue, is unlikely to support any mule deer today, they are surprisingly widespread in the desert southwest wherever native vegetation still thrives and there is enough water to sustain them. Deer are browsers, preferring shrubs and tree foliage to grass, and will travel across the dry desert between water sources snacking on mesquite, fairy duster, jojoba, and other common plants. Today, if you roam a bit further east from Deer Valley to the McDowells and Cave Creek, north to Lake Pleasant or west to the White Tanks, you can find mule deer browsing contentedly on mesquite, or lapping precious water from a pothole after a good rain. South Mountain is also a large enough refuge to sustain a small deer population

Deer Valley Rock Art Center is just half a mile west of the Walgreen’s at the intersection of Deer Valley Road and 35th Avenue. They are open to the public Tuesday through Sunday from 8 am till 2 pm. The modest fee is well worth a morning visit to view the deer of Deer Valley, and to learn more about the ancient peoples and natural history of the area.

Monday, September 28, 2009

Cat Tracks

On an early morning walk up a neighborhood wash after a monsoon rain, I was lucky to cross paths with a bobcat. There were its tracks, fresh prints in the mud, a little less than two inches in diameter with characteristic three-lobed pads. Too large for a domestic cat. The lack of claw marks is another clue that this print was not made by a domestic dog, fox or small coyote, other creatures that commonly cruise the washes. I scanned the corridor and nearby shrubs, hoping to catch a glimpse of this beautiful spotted wild cat, but if it was still around, it was well-camouflaged in leafy shadows.

Several neighbors have been luckier than I, capturing candid photos of bobcats roaming their yards, resting in shade under cars, perched on fences and even lounging on their patios! About double the size of an average domestic cat, the local subspecies, Felis rufus ssp. baileyi, is leaner and lighter colored than stocky northern varieties of bobcats. If your home is adjacent to open space, your chances are higher for seeing desert wildlife, but many species, like the bobcat, are attracted into urban and suburban neighborhoods because of abundant prey.

Photo by Geena Clark

When it comes to finding food, especially for a mom cat with a hungry litter of kittens, hunting around a neighborhood greenbelt is like hitting the fast-food take-out lane. Rabbits, quail, doves, wood rats, rock squirrels, and maybe a fat lizard or two are all on a bobcat’s dining menu. Bobcats will hunt when their prey is most active, which is usually dawn, dusk, or at night. If you are worried that your small dog or cat might look tasty to a bobcat, these are good times to keep vulnerable pets indoors, although they much prefer rabbits and doves to other carnivores.

photo by Richard Halliburton

Are the cats that have been seen recently several or all the same one? We don’t know, but we do know that bobcats are extremely territorial, and rarely range within each other’s turf except to satisfy the urge to mate. Males will roam into several females’ territory, helping to insure that we continue to have bobcats around. Those that survive kittenhood are booted out of their mom’s den after about six months of training in the bobcat arts of cryptic lounging and hunting. Territories are well delineated by scent marks and scratching posts. Depending on prey availability, one bobcat will claim anywhere between 2 and 40 square miles. On the suburban fringe, where prey is very abundant, we may support a denser population of bobcats than the adjacent undeveloped desert.

For many people, a chance to view desert cats and other wildlife from the comfort of our back yard or living room window is one of the benefits of living close to natural open space. The Arizona Game and Fish Department website,, offers lots more information about our wild feline neighbors, including a video. But keep your eyes peeled for the real thing on your early morning and evening walks. And be sure to check your patio too!

Friday, August 21, 2009

Desert Monsoon: The Fifth Season

Unlike much of North America, where each passing year is marked by four seasons, the Sonoran Desert is blessed with five, although some of us might claim that it is all one long summer! The fifth season is our summer monsoon, a stormy season that drenches the desert with torrents and flash floods. Even though it is hotter than heck, this is the most vibrant of Sonoran seasons, the one that defines the region.

Monsoon season generally begins in mid-July and lasts through mid-September. This follows a hot, dry summer that stretches from May through early July, when sane people migrate to more hospitable climates. Monsoon is an Arabic word meaning “shifting wind” and is technically not related to rainstorms. The Sonoran Monsoon marks a time when prevailing winds shift from westerly and northwesterly, to southerly and south easterlies coming from tropical and subtropical regions in Mexico. This is partly generated from the “Bermuda High” that creates hurricanes in the Mid Atlantic Ocean. At the same time, as the desert heats up and hot air rises, a vacuum, or low pressure zone, is created that sucks up moisture from the south. When the air becomes saturated, huge cumulonimbus clouds form, erupting into spectacular downpours and lightning storms that make awe-inspiring entertainment for any sky watcher.

Haboobs, gustanados, macro- and microbursts are some of the wild winds associated with monsoon season. When air from an approaching thunderstorm hits the ground, a massive dust storm rising up to 3000 feet from the desert floor and lasting up to three hours may shroud the landscape. This is a haboob. Gustanados are large dust devils originating from the ground, creating clouds of dust that sometimes look more like smoke. Micro and macro-bursts are powerful downward funnels of air that can create sudden winds up to over 50 mph. The difference is in size, with macro-bursts flowing more than 2.5 miles from their center and lasting 5-20 minutes. Microbursts cover smaller areas for shorter times. When you wake up to a landscape of uprooted trees, it is usually the gustanados or downbursts that are to blame.

Although the winds may be destructive, a monsoon thunderstorm also brings welcome relief from the heat, cooling the air by twenty degrees or more in a few minutes. The rains, however, are spotty, leaving some parts of the desert bone dry, while bringing downpours to other areas. Even if our neighborhood receives no rain at all, a storm over Deem Hills could result in flash floods in small arroyos and nearby Skunk Creek. An average storm will drop 2 inches of rain where it falls, or a quarter of the average annual rainfall in the Phoenix metro area of about 8 inches!

Summer rains also bring new life to the desert. We are gifted with a second season of wildflowers, featuring bright orange Arizona poppies (Kallstroemia grandiflora). These are not poppies at all, but are more closely related to creosote bush. Hornworms, the larvae of sphinx moths, and other caterpillars may also emerge in abundance. Butterflies break from chrysalises. Toads wake from summer hibernation in cool burrows to mate and lay eggs in pools created by rainstorms. People are wakened from summer torpor as well, with hope for a cooler fall season. This is a good time to start planting a winter garden.

For more information about monsoon weather and ecology, check out “A Natural History of the Sonoran Desert,” published by the Arizona Sonoran Desert Museum in Tucson, or pull up the ASU Dept. of Geographical Sciences and Urban Planning meteorology webpage at

Sunday, July 5, 2009


Photo by Richerd Fieling

Shallow mounds of fresh soil, scattered remains of spiny cactus fruit, and small holes around the base of boulders and shrubs are the first signs to look for. If you are walking in the desert hills or along trails around the neighborhood and find these clues, you may spot one of the three species of ground squirrels that share our big backyard. In the cooler mornings and evenings, a patient observer will almost certainly catch a glimpse of one of these common native rodents in the area.

Most abundant of the three are Round-tailed Ground Squirrels, also known as Spermophilus tereticaudus to mammalogists. The Latin translates to “seed-lover with round tail.” Looking like miniature prairie dogs, just nine inches long including their thin, furry, black-tipped tail, the pale tan squirrels will sit up on their hind legs to survey their territory, then retreat into one of their holes at the slightest threat. Like the prairie dog, these tiny squirrels are also social, living in family colonies of about a dozen. They are also very vocal, peeping and chirping to each other to warn of danger. Their elaborate network of tunnels and chambers may have several dozen entrance holes leading to chambers three feet below the surface. As with all ground squirrels, their ears are small and flattened against their head, an adaptation that helps them to navigate underground more easily.

About twice the size of the Round-tail, and less common at this elevation, is the Rock Squirrel, Spermophilus variegatus. Their fur is a darker “variegated” color, sometimes looking white-spotted or mottled gray. Rather than a round tail, they sport a broad bushy tail like a tree squirrel. By no means limited to rocks, these squirrels are adept climbers and can be seen up in trees and on roofs as well as perching as sentinels on top of rock walls or boulders. When threatened they will make a loud, shrill whistling sound. Unlike the Round-tail, these squirrels are mostly solitary except when mating or raising pups. They are also the most likely to invade your home, being bold enough to scavenge around in a garage or patio for food.

Ammospermophilus harrisii, the Antelope Ground Squirrel, is the third, whose Latin name means “sand and seed-loving, named after Harris.” You’ll easily recognize an Antelope Ground Squirrel by the racing stripes running down their sides, plus a flat furry tail that arches over their backs when they run for cover. These are the most desert-adapted of the three, being the only one that is active year round, even during midday in the summers. To the contrary, Rock squirrels and Round-tails will both be dormant in their dens during the hottest and coldest times of the year, and are rarely seen during midday whenever temperatures hit triple digits. Like the Rock Squirrel, they are solitary unless mating or raising pups. Their warning call is a chattering sound. Of the three, the Antelope is least common around housing areas, and more likely to be seen in more rocky territory of the wild desert.

Although all the ground squirrels are named as “seed lovers,” they are also opportunists that feed on cacti, insects, carrion, bird eggs, roots and green vegetation whenever available. They are extremely well adapted to desert climates, deriving nearly all of their water from the food they eat. Being prey species, they are hunted by coyotes, owls, hawks, snakes, fox, and bobcat. But if they survive the hardships of desert life and are quick enough to evade predators, they can enjoy basking in the morning sun, raise a few litters of pups, and eat seeds for a few seasons.

Monday, May 25, 2009

Barrel Cactus

My son Orion standing next to a large barrel cactus

May 2009
Growing up to nine feet tall and nearly twenty inches in diameter, a large barrel cactus may sometimes be mistaken for a young saguaro from a distance. A look at the spines is an easy way to distinguish between the two: barrels have thick, yellowish or red hooked spines; saguaro spines are slender, straight and silvery gray. Both have pleated stems that expand and contract to allow maximum water storage when rains are plentiful. But a barrel will never grow arms, as does a saguaro after fifty years or so.

The Deem Hills are home to thousands of barrel cacti, known to botanists by their Latin name, Ferocactus cylindraceus. The prefix “Fero-” is derived from the Latin word ferox, which means wild or fierce. This is a good description for these robust cacti that are well protected by sharp stout spines and are tolerant of extreme heat and drought. This species is one of more than twenty kinds of barrel cactus found in North America, five of which are native to Arizona.

Their common name refers to the size, shape and capacity to store water. Historically, many Native American tribes have used the mashed pulp of these hefty cacti for food and moisture, but for most people, attempting to extract water from a barrel cactus requires more energy than it would be worth. The bitter, slimy yellow pulp of the cactus is also mildly toxic, inducing headaches, vomiting and diarrhea. Other creatures are immune to these effects, however, so bighorn sheep, wild burros, jackrabbits and packrats gain some nutrition from barrel cactus if they can manage to gnaw past the spines.

Another type of food produced by barrel cacti is nutritious nectar that seeps from the base of the spines. Ants are especially attracted to the nectar, gathering the sweet liquid to bring to their colonies where it is fed to the growing larvae. In exchange for the nectar reward, ants help defend the cacti from other insects that might devour their flesh. Nearby anthills also create nutrient and moisture rich soils that nourish the cacti.

A crown of yellow or orange flowers bloom from March through June, attracting many types of beetles and bees that rummage around as they collect pollen. These insects provide the important service of pollinating the flowers so that they can produce fruit and seeds that may grow into the next generation of cacti. The fruits look like tiny pineapples, but are filled with seeds and very little pulp. Humans, as well as many species of wildlife relish the buds, flowers, seeds and fruits, much like those of other types of cacti, such as cholla and saguaro, whose buds and fruits were a mainstay of traditional Native American diets.
Each barrel is anchored to the rocky slopes that it lives on by shallow roots that soak up any moisture that falls throughout the year, whether it be a light winter sprinkle, or a late summer deluge. When the earth is soaked, the cactus will produce a network of new roots to increase the uptake of water, ensuring its survival through long periods of drought.

The shallow roots are a weakness for these otherwise hearty cacti, since they are easily toppled by erosion or anything else that might disturb the soil around them. Another threat to barrel cacti is vandals and collectors that may damage or poach them from wildlands. Like all other native cacti in Arizona, these plants are protected by State Law. Under Arizona Revised Statutes, it is prohibited to “destroy, dig up, mutilate, collect, cut, harvest, or take” any barrel cactus on state or other public lands without obtaining a special permit. Fines up to $5,000 may be issued for violation of these laws. Barrels are popular landscaping plants, and can be legally purchased at nurseries that have obtained them through sellers with salvage permits, or grown from seed.

The Other Cardinals

March 2009
The Phoenix Cardinals gave all of us something to cheer about this year, but now that football season is over, you may want to go check out Arizona’s other Cardinals, the birds! Our teams’ handsome mascot, a male Northern Cardinal, is native to the state and fairly common down here in desert regions. (By contrast, the football team is not native to Arizona: the team originated in south Chicago in 1898, then migrated to St. Louis, Missouri in 1960. It wasn't until 1988 that Phoenix became the territorial center for the team.)

With their jaunty mohawk, brilliant red plumage, black face and orange beak, male Cardinals are one of the easiest birds in the country to recognize. They have a vast distribution, ranging all the way from southeastern Canada to Guatemala, and stretching from Maine to the Baja Peninsula. For some reason they don't make it over the Continental Divide, so they are most common in eastern North America. They are honored as the state bird in Illinois, Indiana, Kentucky, North Carolina, Ohio, Virginia and West Virginia. But not in Missouri (Bluebird) or Arizona (Cactus Wren).

If you spot a bright red male, there is usually a female nearby. Cardinals are devoted mates and travel with each other year round. As is common in the avian world, females are not as colorful so that they are better camouflaged during nesting season. But she is quite elegant in buffy gray feathers tinged with red on the crest, tail and wings. Cardinals are also well known in the bird-watching world for the clear, melodious songs exchanged between mates or territorial rivals. At this, both males and females are equally gifted.

Female cardinals tend to choose the reddest males as partners because they become the best mates and fathers, being better able to defend their territory and provide food for the family. In order to maintain their feathers' scarlet sheen, they need to feed on insects and fruits high in carotenoids during their molting period.

Cardinals are common throughout their range in thickets, riparian areas and in suburban shrubs and trees. They are non-migratory, so can be seen throughout the year in good habitat. Here in Arizona they are restricted to the southern parts of the state and are most common along washes and rivers, but not so much in very dry areas of the desert. They love thick mesquite bosques that provide protective cover from predators. Bright red wolfberries are a favorite food that helps maintain the scarlet sheen of their feathers. In the Deem Hills you are most likely to see a Cardinal on the north side in the trees along the wash that runs along the base of the Hills. Occasionally a pair will establish territory in the neighborhoods, especially if there is dense natural vegetation in a nearby wash or open space.

The name Cardinal actually originated from the Catholic Church when the Pope’s principle advisors were named Cardinals, which means “important” or “main.” The official robes of cardinals were dyed bright red to symbolize the blood of Christ and the idea that these bishops would die for their faith. From then on, certain shades of red have been known as “cardinal” red. Some bishops also wear pointy hats as part of their ceremonial garb. That is why European naturalists were reminded of the Roman Catholic cardinals when they first encountered these amazing red birds.


Photo by Rhonda Spencer

January 2009
The first time I saw a roadrunner in the wild, as opposed to on Saturday morning cartoons, it was darting across a sea of asphalt at a nearby mall. This was a huge disappointment to me at first, wanting to believe that roadrunners are one of the desert’s wilder creatures, a symbol of natural beauty and testimony that we haven’t infiltrated all of nature somehow. But after watching this prehistoric looking offshoot of the dinosaurs blaze through a parking lot, I now admire the roadrunner even more. Here is a creature that, like his adversary, the coyote, is able to adapt to the worst of human intrusions into their natural habitat. An opportunist at heart, the roadrunner fares well in both the most remote desert refuge and the starkest urban wilderness.

Here on the suburban fringe, the local roadrunner population can navigate between worlds, snacking on fat lizards that inhabit our lush neighborhoods, and retreating to the hills where nesting and rearing young may be a bit safer. You are as likely to see one hopping across a six-foot high cinder block wall to scope out someone’s back yard, as you are to catch a glimpse of one dashing through the brittlebush off a desert trail.

At two feet long, and half of that their iridescent black tail, roadrunners are unmistakable. You can see them any time of year in the Deem Hills, although during the cooler winter months, they are more likely to be spotted during the day after they’ve had a chance to warm in the sun. During the summer, like most other desert critters, they will evade the heat by hunting at dawn and dusk.

Roadrunners are mostly carnivorous, revered for their ability to prey on young rattlesnakes and scorpions. They also devour small rodents, spiders, insects and small birds. A close look at their sharp stout beak and four curved claws makes it clear that they are gifted with hunting skills equal to raptors. Although roadrunners are not adept flyers, they can reach running speeds of up to 18 miles per hour, giving their main predators, coyotes, raccoons and hawks, a good chase. When meat is scarce or fruit abundant, roadrunners will supplement their diet with cactus fruit and seeds.

While roadrunners are solitary hunters, they are monogamous and mate for life, a rare feat for any creature. Either partner may initiate courtship rituals by chasing the other around their territory. They also engage in an energetic display of hopping, wing flapping and tail fanning. Things get more intense when one presents the other with a stick, a prelude to nest building. The male calls the final shot when he brings the female a gift of a lizard or other tempting morsel, which she accepts after mating. The two share all of the parenting responsibilities, including nest-building, incubating eggs, and feeding the young. The brood of two to six young roadrunners fledges after about three weeks. They are independent hunters after another couple weeks of training. Once the first brood is off and running on its own, the parents may start a second nest for the season.

Lizard Safari

October 2008
Armed with a butterfly net, field guide and a shoebox, my six-year-old son and I embark on a neighborhood safari in search of tigers, leopards and zebras. This is not a pretend expedition: these are common names of some of the dozens of lizard species that live around Phoenix. Maricopa County is heaven for serious herpetologists, those who study reptiles and amphibians. My son has added herpetologist to a long list of professions he intends to pursue in his lifetime, so we are living in the right place. Of over 130 “herp” species that occur in the entire state of Arizona, 82 can be found in this county. Twenty-eight of those are lizards, which includes geckos, skinks, iguanas and Gila monsters.

While many reptilian creatures, especially rattlesnakes, inspire terror in most people, nearly everyone loves lizards. Local lizards are not venomous, except for the rarely seen Gila monster. Lizards are great for natural pest management, feasting on crickets, termites, spiders and other critters we don’t like to have in our houses. They remind us of dinosaurs and dragons, every child’s fantasy pet. Lizards are just plain cute.

We spot our first specimen basking on a boulder, well camouflaged against the brown and gray speckled rock. Flipping through our field guide, we discover that we’ve found one of the most ubiquitous of Arizona’s herps, the ornate tree lizard. These little guys have adapted to just about every habitat in the state, from the most remote canyons of the Colorado River to cinder-block “cliffs” in downtown Phoenix. Plus, as their name suggests, they like to climb trees. Blue patches on the sides of its belly tell us that this one is a male. The tree lizard darts under a spiny cholla cactus, where we decide to let it be.

Up the wash, another lizard dashes across the path. “Look, a tiger!” shouts Orion. He races after the lizard, a young tiger whiptail. Eleven of the 50+ species of lizard in Arizona are whiptails, distinguished by slender tails that are longer than their body. Juveniles of this species have bright blue tails and pinstripes on their back. As they age, the stripes and tails fade to a mottled brown. These guys are tricky to catch, being ultra-speedy, but this one is no match for an eager first grader. The lizard squirms in the net and is then put into the cardboard box so we can get a close look at him. Or is it a her? Many whiptail species are known to be parthenogenetic, meaning that entire populations are all females that produce eggs without mating. Ours is not a clone, however, since tiger whiptails reproduce the old fashioned way. At this lizard’s young age, however, it’s tough to tell male from female.

This is a catch and release expedition, so we gently let the tiger go under a shrub, where it disappears quickly in a rustle of dry leaves. We move on to check dark crevices in a boulder field for chuckwallas. These are the behemoths of Sonoran desert lizards, measuring up to a foot and a half from their nose to the tip of their tail. Our next-door neighbor had seen one nearby just a week before. No such luck today. Back home, we add the day’s observations to our Deem Hills wildlife log, which now has eight kinds of lizard. Not bad for a suburban safari!

Want to learn more about lizards in your backyard? Check out “A Field Guide to Amphibians and Reptiles in Arizona” by Thomas Brennan and Andrew Holycross, or log on to their nifty website at

Summer Skies and Scorpions

July 2008
According to Greek legend, the venomous sting of a scorpion killed Orion, the great hunting god. One of many stories about Orion’s fate tells that the Greek goddess Artemis cursed him with the fatal sting because she was jealous of his courting Dawn, the goddess of morning. During the summer, the constellation Orion can be seen lying down on the eastern horizon, greeting his lover just as the sun rises. At the same time, the constellation Scorpius sets to the west. Likewise, Orion is most visible in the night sky in mid-winter, opposite Scorpius, which some say is because they are carefully avoiding each other.

During mid-summer, stars that make up the sweeping spiral tail and claws of the constellation Scorpius dominate the southern night sky. These are clearly visible even around the light drenched city of Phoenix. At the heart of Scorpius shines Antares, a huge star 300 times the size of our sun. The name Antares is Greek for “rival of Mars,” because they both glow red and are about the same size to our eyes when viewed from Earth. However, if Antares were the center of our solar system, it would swallow Mars and reach almost to the planet Jupiter!

Summer nights are also the most likely time that you will see a living scorpion in the desert, since they are nocturnal and more active during warmer months. Scorpions have been very successful, having survived at least 350 million years on our ever-changing planet. Of the 1500+ species known world wide, 90+ are found in the U.S.; about thirty live in both wild and tamed regions of Arizona. Three of these are common, and likely to be seen in the Deem Hills and surrounding neighborhoods if one cares to look for them. The most spectacular but least common of the three, is the giant hairy desert scorpion, a dark-skinned beast that grows up to six inches long. Although frightening to look at, this species is not very toxic to humans. But if you were an insect, lizard, spider, or other scorpion, you would definitely want to stay out of their way.

The less intimidating striped devil scorpion grows to less than three inches long, and is blonde or tan with broad dark stripes down the length of their backs. This species is also not life threatening to humans, though the sting can be very painful.

The bark scorpion is the only one in our area that is highly toxic to humans. They are also blonde and similar in size to the striped devil, but lacking the stripes. A well-aimed sting from a bark scorpion can immobilize a 250-pound man, and could be fatal to a small child, unhealthy adult or small pet. The powerful neurotoxin causes numerous symptoms including a sharp tingling sensation, numbing, uncontrolled breathing, muscle spasms, and general aching. Some people suffer allergic reactions to the sting as well.

Fortunately, scorpions are not aggressive towards humans, and will only sting if threatened. They hide in rock crevices or burrows in the soil during the day, when humans are more likely to be outside. At night when they are active, it is not uncommon to see one cruising down the sidewalk or crawling on a tree trunk. If you shine a black light around your yard or in the desert on a moonless night, you will be able to easily find them glowing greenish white in the dark. Other than humans, the main predators of scorpions are nocturnal animals including snakes, mice, shrews, elf owls and other scorpions.

If you do not feel comfortable sharing your space with scorpions, be sure to keep your yard tidy and free of debris where they like to hide. Look carefully before you put your hands or feet under rocks, in woodpiles, or even when moving outdoor potted plants. Don’t leave close-toed shoes outdoors and avoid going outside barefoot at night. You can also have an exterminator treat your property with a special arachnid poison. Scorpions are not insects, so insecticides will not affect them. However, insecticides are useful if you want to eliminate prey that would attract scorpions to your home.

Although it is true that the sting of some species of scorpion can be fatal to even a very strong man, this is extremely rare. According to current medical records, there have only been two deaths in Arizona due to scorpion stings since 1968. Compared to other risks we face each day, these creatures are relatively benign. If you can overlook their venomous capability, they are fascinating to see and watch.

Palo Verdes: Yellow Clouds, Green Sticks

May 2008
Arizona’s state tree, the Palo Verde, is named for the distinctive green trunks and branches, but could easily be named Nube Amarillo for the bright yellow clouds they become when in bloom. There are three wild species, the Littleleaf Palo Verde, Blue Palo Verde and Mexican Palo Verde. A hybrid of all three, dubbed the “Museum Variety,” is commonly used in landscaping and combines the best features of each species into a drought hearty thornless tree with large showy yellow flowers.

April and May is show time for Palo Verdes in the Sonoran desert. On the dry rocky slopes of Deem Hills, the Littleleaf, a.k.a. Foothills Palo Verde (Cercidium microphyllum), is super abundant. Their natural form is more like a large shrub, with branches growing in a roundish tangle that drapes to the ground, creating shade for sun sensitive young saguaros and thick growths of annual wildflowers. These slow-growing trees live to several hundred years old, providing food and shelter to many species of wildlife, including javelina, rock squirrels, rabbits and hares, many species of birds, beetles and over twenty native species of bee. Thick growths of mistletoe also attract birds that feed on the berries. Palo Verde seeds, pods and flowers are edible for humans as well, and provided a main source of food for early Native Americans in the desert. The delicate pale yellow flowers of Littleleaf Palo Verde develop into woody pods that look like strings of beads.

Along washes and in floodplains, the Blue Palo Verde (Cercidium floridum) is more common, and is easily distinguished from the Littleleaf by the bright yellow flowers and graceful, upward sweeping branches. Their pods are broad, flat and papery compared to their cousins in the foothills. Because they grow where there is more moisture, the wood is softer and they also live only to about one hundred years old rather than several centuries.

The scrubby Mexican Palo Verde (Parkinsonia aculeata) is the thorniest species, and has an orange or orange-speckled petal on its flowers. These are more common along sandy washes in southern parts of the Sonoran Desert.

Although Palo Verdes have thousands of tiny leaves (as anyone who has one planted near a pool well knows!), the bright green bark takes care of about 75% of the photosynthesis for the tree, allowing them to endure years of severe drought when leaves are an expensive luxury. During seasons of drought and cold, most of the leaves are dropped to conserve moisture.

No matter what sort of winter rains or not have blessed the land, Palo Verdes are reliable bloomers during late spring, creating drifts of dried flowers along trails and roadsides. If you aren’t spooked by bees, sitting under a blooming Palo Verde is a multi-sensory treat. The golden canopy hums with bees, bathing you in yellow light and the sweet scent of nectar. Every spring I take my kids on a walk to visit the “gold room” of a blooming Palo Verde. There, looking up through green branches to the blue sky is another reminder why we love our neighborhood and its big backyard.

Sunday, May 24, 2009

Hummers in the Hills

March 2008
There are few birds as familiar and inspirational as hummers, both delicate and powerful enough to be namesakes of gems and gods. The Aztecs worshipped a deity named Huitzilopochtli, who was depicted as a hummingbird or “huitzel” which means “shining one with weapon-like thorn.” The Portugese call them “beija-flor,” or “flower kissers;” in Spanish they are named “joyas voladores,” or “flying jewels.”

All 338 species of hummingbird are native only to the Western hemisphere. Of those, eighteen have ventured north of the Mexican border. Half again (9) have been spotted flitting about the Phoenix metro area. But only three are common to the Deem Hills territory: the robust Anna’s, the petite Costa’s, and the slender Black-chinned hummingbird.

Of those three, you are most likely to see an Anna’s on any given day. Fifty years ago, Anna’s hummingbird would be an uncommon sight in Phoenix most of the year. But with the growth of suburbs and irrigated garden landscapes, these tiny aeronauts have expanded their range from coastal California to become year-round residents and breeders in this oasis of the Sonoran Desert. The species was named in honor of Anna Massena, Duchess of Rivoli, who was married to an ornithologist named Francois Massena. Both were friends of Rene Lesson, a French naturalist and surgeon. Lesson was one of the first Europeans to publish scientific records of hummingbirds after sailing around the world on an expedition exploring the islands of the South Pacific and coast of South America in the 1820’s. In addition to being the only fully red-headed hummingbird, Anna’s males are well-known for their spectacular courtship and territorial displays in which they dive from 100 feet in the air at 60 mph, coming out just before they reach the ground and punctuating their feat with a loud squeak.

Costa’s are the most desert-adapted species of the three, although they will escape to the tropics during the blistering heat of summer, returning between October and May to breed. These are the most likely to be seen up in the Deem Hills, where they will seek out ocotillo, desert lavender, fairy duster, wolfberry and other nectar-producing native plants. In good light, the male sports a purple forehead and throat, with long “sideburn” feathers. This species is much smaller than the Anna’s, but with a shortish neck that makes them look “small and dumpy” according to Sibley’s Guide to Birds. The courtship display of Costa’s is distinguished by shrill whistling while performing repeated loops 75-120 feet in the air. This species is also a namesake of French nobility, an ornithologist and collector named Louis Costa.

The Black-chinned is known as our “summer hummer” because they keep a schedule opposite to that of Costa’s, wintering in Mexico and breeding in the southwestern U.S. between April and July. The males have a velvety black chin and deep purple throat with a whiter chest than the grayish-green chested Anna’s. They are most likely to be seen along washes or in suburban areas where there is more water during the hot summer. If you see a hummer dancing back and forth in a low u-shaped arc, you are witnessing Black-chinned courtship.

Hiking and History in the Deem Hills

January 2008
The Deem Hills has a trail fairy! If you are one of the regulars up in the Hills, you’ve likely noticed that many of the trails are now much easier to follow than they were a year ago. We can offer thanks for the efforts of a hardworking person (or group?) who has been busy moving rocks and placing cairns to navigate through tricky sections. Our trail fairy has also designated one of the main trails as the “Rusty Angel Trail,” which is clearly posted with a beautifully crafted copper trailhead sign.

Geocachers have also been busy in and around the Deem Hills. At least eight different caches are posted on the internationally accessible network for GPS treasure hunt enthusiasts. The most recently posted cache is named “W. Deem Hills Pkwy,” just established on November 12, 2007. Back in March 2003, another cache was stashed and named “Dem Deem’s Finally Have a Cache.” Two others are named after Sandra Day O’Connor High School. (To learn more, register and log in at

Summit baggers have also left their marks in the hills, with logs left at the tops of high points in small jars. On the lofty 2098 foot summit of Deem Hills Ridge, six hundred feet up from the valley floor, the current log was first established on December 5th 2001. The jar is easy to find among the rocks beneath a desert lavender shrub, but you may want to bring your own pen. Since then, over a dozen parties have signed in to mark their achievement and comment on the splendid view.

These historical markers, along with flags, boulder graffiti and graduating class paint jobs are notable because as the area’s human population grows, so does the use of open space and trails. While the City of Phoenix is actively developing recreational facilities on the west side of Deem Hills, there are currently no plans for further trail development in this Desert Preserve by the City. It is up to the citizens to educate others and care for our open space!

To find the Rusty Angel trailhead, you’ll need to make your way to the end of Pinnacle Vista Road on the north side of the Hills. From the small parking area there, walk up a steep hill on the paved road that leads to a fenced water storage tank. Look for the Arizona-shaped copper sign posted on the south (left) side of the road near the top. Another major trailhead begins at the north end of Hackberry Lane in the neighborhood of Stetson Hills, but has no public parking and no trailhead sign. From both of these trailheads, you can access over five miles of beautiful, rocky desert trails.

Fringe Benefits: Desert Cats

November 2007
Bobcats have been roaming the neighborhood lately. Of course, they have been doing so for hundreds, maybe thousands of years. But within the last decade, the neighborhood has been transformed from natural desert to a relatively lush landscape that is a veritable heaven for the bobcats’ favorite prey, cottontail rabbits.

If your personal pet is about the size of a rabbit or hare, you may be alarmed. A hungry bobcat may not discriminate one tasty ball of fur from another, except that bunnies don’t bark. For many people though, a chance to view desert cats and other wildlife from the comfort of our patios is one of the benefits of living on the suburban fringe!

Like housecats, bobcats purr and are excellent tree climbers. Their favorite activity is lounging. During the day, a bobcat will find a quiet shelter to snooze, and with desert colored and dappled coat, become nearly invisible to passers by. Curious, but wary, bobcats generally avoid contact with humans, which are the most dangerous predator of wild felines. To the contrary, there are no records of bobcats preying on humans.

When it comes to finding food, especially for a hungry litter of kittens, roaming into a neighborhood greenbelt is like hitting the fast-food take-out lane for a desert cat. Rabbits, quail, doves, wood rats, rock squirrels, and maybe a fat lizard or two are all on the bobcats dining menu. If any of these creatures hang out in your yard, the cats may be stopping by for a visit when you aren’t looking. Bobcats will hunt when their prey is most active, which is usually dawn, dusk, or at night. These are good times to keep vulnerable pets indoors.

Are the cats that have been seen recently several or all the same one? We don’t know, but we do know that bobcats are extremely territorial, and rarely range within each other’s turf except to satisfy the urge to mate. Males will roam into several females’ territory, helping to insure that we continue to have bobcats around. Those that survive kittenhood are booted out of their mom’s den after about six months of training in the bobcat arts of cryptic lounging and hunting. Territories are well delineated by scent marks and scratching posts. Depending on prey availability, one bobcat will claim anywhere between 2 and 40 square miles. On the suburban fringe, where prey is very abundant, we may support a denser population of bobcats than the adjacent undeveloped desert.

The Phoenix area is home to one of twelve subspecies of bobcat. Ours, Felis rufus ssp. baileyi, is a lighter colored and more petite cat than northern varieties. They are about double the size of an average domestic cat, usually weighing in at 15-25 pounds and measuring just under two feet tall and less than three feet long, plus the bobbed tail that is their namesake.

For lots more information on our wild neighbors, check out the Arizona Game and Fish Department website:


September 2007
As the summer nights cool enough to leave the windows open, each new day is most often greeted with the lonely call of mourning doves wafting through the screens. Anyone who takes advantage of mornings to walk the trails and washes around the neighborhood will also begin the day flushing flocks of long-tailed doves, adding their distinctive wing whistle to the dawn concert.

Mourning doves are the most common of four species of doves that visit the Deem Hills and surrounding neighborhoods. Others include the smaller Inca dove, the white-winged dove, and rock dove, aka pigeon. All but the rock dove are native to the southwest; rock doves were introduced from Europe hundreds of years ago as game birds. All of the doves are well adapted to suburban environments where there is more water and agricultural areas for food than may be available in natural habitats. Whether you consider these birds a menace (they do poop a lot!), or beautiful members of the community, they are fun to watch and listen to.

Phoenix native, Stevie Nicks, made the white-winged dove a household bird in the 1980’s with her hit song “Edge of Seventeen.” They are named for distinctive white patches on their wings, most obvious in flight, and also have red eyes accented by a dark streak below their cheek. These are the least common of the four doves in our area by the fact that they are also the most closely tied to natural areas with saguaro. White-winged doves feed on pollen, nectar, fruit and seeds of saguaro cacti, and are one of the most important pollinators and seed dispersers for our state symbol. These birds are also migratory, breeding in southwest deserts between April and September, coincident with Saguaro flowering and fruiting, and wintering further south.

Inca doves actually have no known relationship with native tribes in South America, but are very common throughout Mexico and Central America. Like the white-winged dove, Incas are best adapted to warmer tropical climates, and are less common in cooler northern areas, though they are expanding their range. They are much smaller than the other doves, and are also easily recognized by the scalloped pattern of their dark-rimmed feathers, plus a rusty-colored underwing in flight. If you ever see a group of doves huddled on top of each other, they would be Incas. “Pyramid roosting” is an odd behavior they engage in, stacking up to 3 layers of about a dozen birds, possibly to help keep each other warm.

Robust rock doves are found throughout North America, mostly in association with people. Their throaty “purring” call and iridescent feathers are a staple of most urban environments where they will roost on building ledges and feed on leftovers.

Even with all these avian cousins around, it is the slender mourning dove that seems to soften the hot desert days with its song and beauty. Look for the long pointy tail and spotted wing feathers, which are common treasures to find on trails, although usually a sign that a dove has been prey to owls and hawks in the area. Whenever I pick one up, I also pray for the peace and hope that doves symbolize.

Choose Your Favorite Cholla

July 2007
Next to the giant saguaro, the many bizarre forms of cholla cacti are some of the most distinctive wild plants of the Sonoran desert. Of more than thirty species of cholla that grow throughout Arizona, three are common in the Deem Hills Mountain Preserve that overlook the neighborhood of Stetson Hills.

Perhaps the most well-known is the fuzzy looking teddy bear cholla (Opuntia bigelovii), also called silver cholla for the way its blonde spines shine when backlit by morning or evening sun. The loosely attached joints or “balls” easily hitch onto unwary wild animals and humans. Interestingly, packrats seem immune to the barbed spines of the teddy bear cholla and will pile the balls at the entrance to their dens to deter predators such as fox and coyotes. Many birds, most notably the cactus wren, are also able to defy the barbs and find well-armed protection for their nests in the branches of the teddy bear and other chollas. A comb is a good tool to keep in your purse or pack whenever walking in the desert. If a cholla ball “jumps” onto you, just pry it off with the comb! NEVER touch or kick a cholla ball!

Look for the bright red, spineless, berry-like fruit of the desert Christmas cactus (Opuntia leptocaulis) sprawling in the shade of leafy shrubs or trees. The slender stems of this cholla are only 1/8-1/4 inch in diameter, making the half-inch long spines look very fierce in comparison. The stems of pencil cholla (Opuntia arbuscula) are also very slender but about twice as thick as the Christmas cactus, and have drab greenish fruit.

Buckhorn cholla (Opuntia acanthocarpa) is the most common of the three species found in Deem Hills and is named for branches that sort of resemble deer antlers. The flowers of buckhorn vary from bronze to pale yellow to reddish. Flower buds of the buckhorn were once a major source of food for native peoples of the area and were gathered every spring, then roasted and dried for storage to be used throughout the year for soups and stews. The fruits of chollas can also be eaten, but have not been as popular as the flower buds because they are so spiny. Cholla fruits and buds are also important food for many other desert dwellers, such as tortoise, javelina, packrats, birds and jackrabbits.

Chollas are closely related to prickly pear cacti, but have cylindrical stems rather than flat pads. Like prickly pears, chollas easily reproduce new plants when pieces of stems or fruit break off and grow roots. If you want to grow a locally native cholla in your home landscape, just choose your favorite cholla and carefully transplant a piece to your yard. They are easy to grow and need only lots of sun and what little water falls from the sky to thrive.

Tortoise Island

May 2007

If you see a rock move on its own in the desert, look again. That rock may be a tortoise. In the Deem Hills, desert tortoises have been sighted by at least three neighbors I’ve talked with. Two of the tortoises were quite large animals (12” long or so), resolutely lumbering across the trail above Hackberry Lane. Unfortunately, the third sighting was only a shell and a few bones, the rest of the tortoise having been a good-sized meal for some other desert animal. Were all three sightings of the same tortoise? Or are there more of these amazing animals surviving in the desert island of our big backyard?

In the Sonoran desert, tortoises are fairly common, preferring hilly, rocky territory where palo verde and saguaros grow, which fits the description of Deem Hills. Tortoises spend their lives in a narrow range of a few square miles and are mostly solitary. Their continued survival depends on males and females meeting one another occasionally, but only occasionally, as the females can retain sperm for up to two years and still produce several viable clutches of eggs. Once a female has mated, she may dig a small cavity to lay her eggs sometime between May and July. The eggs hatch about ninety days later, hopefully coincident with the summer rains so that the young tortoises have the best chance of survival.

Since tortoises spend over 90% of their lives resting in rocky dens, shallow burrows, or shady depressions under shrubs, seeing a live tortoise moving around in the wild is a very rare treat for anyone. A tortoise may live up to fifty years in the desert, although survival in the first five years is quite risky due to predation of eggs and young by ravens, coyotes, foxes, roadrunners and other animals. Desert tortoises are most active in late spring and early fall months, or in the cooler mornings and evenings during summer months. They are herbivores, feasting on over a hundred species of plants, including prickly pear cactus, wildflowers and grasses. Almost all of the moisture they need comes from the plants they eat, although they will drink whenever water is available.

Aside from predators, one of the greatest threats to a tortoise is curious people who pick them up and/or take them home for pets. Touching or picking them up may frighten them into releasing stored water, which then may be very difficult to replace, resulting in slow death from dehydration. Capturing, killing, or trading wild tortoises is illegal.

As I wander in the Deem Hills, one of my greatest wishes is that the female tortoise whose shell was left behind, also left dozens of extended family and offspring who are now safely sheltered in their burrows, feeding on prickly pear fruit, resting comfortably beneath a palo verde, and bumping into each other now and then to continue populating our tortoise island.
For more information on Sonoran desert tortoises, visit the Arizona Game and Fish Department web page on desert tortoise management at

From Africa to Arizona: Desert Grasses

Native Deer Grass in a suburban landscape

March 2007
What do the savannahs of Africa and the Sonoran desert of southwestern North America have in common? The savannahs, or desert grasslands, share a similar hot, dry climate with seasonal rains totaling less than 24 inches of precipitation. Both also include leguminous, or “bean” trees as dominant vegetation; in Africa, there are many species of acacia. Here in central Arizona, we have mesquites, ironwoods, and palo verdes, as well as acacias. Cacti, however, are a western species, while in Africa, cactus-like plants called Euphorbias are indigenous.

Because the climates of desert areas on both continents are similar, many of the plant species used in landscaping here in Phoenix are imported from Africa. This works to our advantage much of the time. African acacias, pencil cactus (actually a Euphorb), and elephant food, a succulent sprawling shrub, all easily adapt to urban and suburban living in North America. Aloe’s are also native to southern Africa, and are very popular and elegant elements of landscape design here in the American southwest.

Trading plants across continents may sound like a harmless practice, but when it comes to certain African grasses, the ecological consequences of our landscaping aesthetics do not bode well for the Sonoran desert. If you look up at the Deem Hills, for instance, you will notice large areas where the golden sheaths of buffel grass (Pennisetum ciliare) and fountain grass (Pennisetum setaceum) have covered the landscape. In the spring, we may remark how beautifully green these areas are. In our landscapes, fountain grass has been popular for the beautiful fluffy seed-heads these giant bunchgrasses produce. Unfortunately, although these grasses evolved in similar climates, another important element of the African savannah that is dramatically different from the Sonoran desert is the presence of teeming herds of grazing animals: zebras, wildebeest, gazelles, and over two dozen other species of herbivores migrate throughout the savannah, munching the grasses as they move. Fire is also a natural element of the African savannah to which vegetation and wildlife there has adapted over the millennia.

African Fountain Grass growing with a teddy bear cholla

It is only a matter of time before the beautiful green or golden swaths of African grasses that have escaped from our suburban landscapes into the wild desert will catch fire. There are no herds of zebras or wildebeest to eat them. Range cattle, for which the non-native grasses were originally imported, are not numerous enough to keep them naturally “mowed.” Sonoran desert plants and wildlife do not rebound easily from the effects of wildfire, whereas many non-native grasses thrive even better with fire cycles.

You can help prevent the spread of non-native grasses into our natural open spaces by removing or replacing your fountain grass with grasses native to the Sonoran desert. There are plenty of beautiful species that will complement your landscape without endangering our Big Backyard.

For an excellent selection of native grasses, visit the bi-annual plant sale at the Desert Botanical Garden every March and October, or inquire at your local garden center. Deer grass (Muhlenbergia rigens), big galleta (Hilaria rigida) purple three-awn (Aristida purpurea), side-oats grama (Bouteloua curtipendula) are four excellent, easy-to-find choices. Or, if having exotic African plant species is important to you, try a non-invasive aloe, also available at the plant sale and many garden centers.

Q is for Quail

Illustration by David Sibley from Sibley's Guide to Birds of North America

January 2007
A quirky collection of quail quips....

Walking through the desert in winter, the quiet air is quelled by an explosion of feathers. A covey of quail erupts from the brush, in quantities of up to two hundred birds. Just as quickly, they disappear into the grey-green quilt of desert vegetation.

Gambel’s quail are especially abundant this season after a quantum leap in production as a result of last winter’s prolific rains and thus, abundant food for quails and their chicks. However, this year’s lack of rain will undoubtedly quash the quail population, since there is less fresh vegetation in the desert to quench their hunger and thirst. Plenty of green’s are also necessary to build up a critical quotient of Vitamin A, which triggers reproduction in both the quail male and quail queen. Without the required greens, few to no eggs are produced. Another part of the equation may have to do with dry year diets having a higher quantity of heavy metals, especially from drought resistant locoweeds, which harbor high levels of selenium.

Both male and female sport a quaint quiff of dark feathers on their forehead, also known as a topknot. Males are also equipped with dark face and throat feathers, a red patch on their crown, and white stripes on their cheeks and brow. The less flamboyant female is better camouflaged in order to safely brood her clutch of eggs. The quail quills are the source of the Latin name, Callipepla, which means “beautiful robe”. Arizona’s most common species, Callipepla gambelii, is named after 19th century naturalist, William Gambel, who is also the namesake for Gambel’s oak (Quercus gambelii), mountain chickadee (Poecile gambelii), and leopard lizards (Gambelia ssp.), all of which occur in our area.

Quail couples are monogamous for their short lives of one to four years. Courting begins in late February, and nesting peaks in April and May. Spring call counts provide wildlife managers with a reliable estimate of quail reproduction. Mating males will call loudly from their perches to attract a partner. This years count will probably be a quintile of last years, because of less than average winter rains. In a good year, however, frequent calls indicate mating success. Quantities of up to a dozen eggs are laid in shallow grass-lined depressions on the ground, or occasionally grassy nests built high in scrub. After three weeks, the tiny chicks hatch, and queue through the underbrush with their parents in search of insects, the high-protein diet necessary for early development. In ten days they are able to fly. By the end of summer, a brood of chicks is usually reduced by nearly three quarters (70%), leaving only quintuplets under the best circumstances.

Hunter’s are allowed to bag fifteen birds a day during quail hunting season between October and February, ranking humans as the top predator for these birds. Coyotes, hawks, owls, and bobcats will also pursue these quixotic birds when they are plentiful. Squirrels, snakes, and gila monsters quest for the eggs, and are have no qualms about destroying an entire clutch in order to quaff on the juicy treats.

The quintessence of the Gambel’s quail is their song, a lively variety of calls ranging from quiet peeps to raucous calls. You will usually hear them before you see them, clucking and chattering as they scuff through the underbrush. As the flock feeds, a dominant male will perch as sentry to approaching predators. Although they are primarily ground-feeding birds, pecking about for fresh greens, seeds, fruit, and the occasional insect, quails are quite good fliers, and will quickly soar out of a hunter or predators site with ease, creating their own small earthquake as they take flight. An encounter with a covey of quail is sure to spice up an otherwise quotidian day in the desert.


November 2006
Anyone who walks at dawn or dusk near the Deem Hills will sooner or later be rewarded with the soft, low hoot of a great horned owl. Whether the resonating call of the owl evokes feelings of wild beauty, or primeval dread, it is always a reminder of something greater than the human world to anyone who pauses to listen. If you’re lucky, you may spot the striking silhouette of an owl perched on a saguaro, or see one glide overhead on silent wings.

The great-horned owl is the most common and widespread of North American owls, and a year-round resident wherever they live. They are also the most adaptable, being able to thrive in both wilderness and urban settings, from the coldest northern forests and mountains to the hottest southwest deserts. Standing nearly two feet tall with a wingspan of almost four feet wide, the great horned owl is capable of taking prey ranging from jackrabbits to mice, along with snakes, lizards, frogs, fish and other birds. Owing to their lack of a sense of smell, they are also the commonest predator of skunks. On occasion they will also take an unwary cat or small dog.

Among the six species of owl found in the Sonoran Desert (barn, western screech, pygmy, elf, and burrowing owls are the others), the hoot of the great-horned owl, along with its impressive size, make them easy to identify. Some call them the “5-hooter,” since their most common call has five parts, with the second and third hoot more rapid than the rest. With a little imagination, you can hear them say “Who’s awake? Me too.” The female hoots are shorter and higher than the males.

As with all birds of prey, the female is slightly larger than the male, although it is the male who hoots the most, as he stakes out the one-third to two square mile territory for the pair during much of the year. In winter months, males and females hoot to one another as they engage in courtship and breeding. Nest sites are usually established in cliffs, tree hollows, or on top of old hawk nests. Explorers in the Deem Hills will recognize a few cliff nest sites by the litter of small animal bones and bits of fur on the ground below where young owls have coughed up pellets. Between one and four new hooters fledge and disperse from the nest sites by late March or April. Listen for a hooter near you!

What's the Buzz?

September 2006
Along with the serene beauty of the open space that surrounds our neighborhood, we must also accept the fact that we live in rattlesnake territory. Perhaps no other creature in the desert southwest is as feared or misunderstood as the rattlesnake. However, if met with respect rather than fear, rattlesnakes are fascinating and generally quite shy creatures.

The most common rattlesnake in our area is the western diamondback, one of nearly two dozen species and subspecies in the western U.S. They are easily recognized at a distance by the triangular shaped head and a black-and-white striped tail section that follows the brownish diamond-patterned body. If you wander too close to one, they will warn you with a distinctive buzz of their tail, which when you hear it, is not un-like the buzz of a cicada.

Up to two-dozen rattlesnake eggs are incubated within the female and then born alive in late summer. A wild snake will live for more than twenty years, adding a new segment to its rattle each time it sheds. Since snakes shed three to four times a year, in addition to breaking and losing rattle segments occasionally, the number of segments is not a reliable indicator of age. A healthy old rattler may grow to over seven feet long.

In all of the hours and hundreds of miles of wandering the Deem Hills and neighborhood paths, I have seen four rattlesnakes. One snake had recently been killed by a previous passerby. Another had made itself comfortable in a friends’ backyard. Two others were quietly sheltering under shrubs along the trail. In all of these cases, we took the opportunity to cautiously observe the snake with my 4-year-old son, using the moment to teach him that this is one creature we definitely could not pick up! Since snakes can only strike a distance of about one third their body length, you can safely observe them from about five feet or more.

Rattlesnakes are not aggressive towards humans by nature. We are simply too big too eat. However, like humans, they will try to defend themselves when they feel threatened. Thus, the vast majority of venomous snakebites are delivered to people who attempt to handle, harass, or kill the snake. The best thing to do when you see a rattlesnake is to heed their warning rattle, 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. However, if you threaten it with a stick, or try to hurt or kill it, it may attempt to strike you.

If a snake decides to explore your backyard, there are humane ways to remove them. The Phoenix Herpetological Society (, whose primary mission is to promote coexistence, respect, and understanding of native reptiles, will relocate animals in conflict with human communities for a small fee. They will collect the snake with tongs and return them to natural desert habitat. Making sure that your yard is not attractive to rodents is the best way to make sure that snakes don’t also take up residence there.

Deem Hills Rocks!

Brooke and Orion on the summit of Wildcat Peak in Deem Hills
July 2006
From the lofty summit of Deem Hills, at 2100 feet above sea level, and 600 feet above the valley floor, you can get a beautiful 360-degree view of the landscape. Like many of the surrounding desert peaks, Deem Hills is made of rubble leftover from volcanic eruptions that occurred between two and five million years ago, which is relatively recent by geologic standards. The dark rocks, called basalt, glow deep purple and orange in the evening sun. Basalt is basically cooled off lava. Here, many of the rocks have pits and holes in them, evidence that the lava was almost frothy when it flowed and then quickly cooled, leaving small air bubbles in the rock.

According to archeologists in the Phoenix area, rocks found on Deem Hills were prized by native peoples for hundreds of years. Both the basalt and a white rock called chalcedony (pronounced “kal-sed-nee”) were used for many types of tools by prehistoric cultures. The basalt is especially useful to make manos and metates, which are stones commonly used for grinding mesquite pods and grains into flour. Basalt can also be shaped into hammers and axes.

On the south face of the hills there is a thin band of chalcedony, which is a fine-grained quartz that can be shaped into arrowheads, knives and scrapers. An ancient quarry just below the east ridge of Deem Hills was a primary source for people throughout the region who migrated along the Skunk Creek corridor. Because the quality of chalcedony in the Deem Hills is very good, rocks were probably traded for many miles from the source. Some contemporary Native Americans teach that chalcedony is a sacred stone, and is said to augment emotional balance, vitality, stamina, endurance, kindness, charity and friendliness.

Another interesting rock phenomenon in the area are the smooth and translucent white nodules of calcite that have eroded out of the outcrops of chalcedony. The nodules are usually about half an inch in diameter, and are common along all of the trails in Deem Hills. I call them "desert pearls." These would make pretty beads for someone who is feeling creative!

For more information about the local geology and archaeology, visit the Deer Valley Rock Art Center at 3711 West Deer Valley Road, below the Adobe Dam just 2 miles south of Deem Hills.

Desert Icons

May 2006
Our state flower is the saguaro, and will be blooming most abundantly in the month of May. This is a show not to be missed! Arizona is unique in that the saguaro cactus does not grow naturally anywhere else in the country, except perhaps a few stragglers in California. The saguaro has also been an icon and important cultural plant in the southwest for centuries.

The Deem Hills is home to some beautiful wild specimens of saguaro and the community of birds, insects and other animals that depend on them. If you want to see saguaros in bloom, the best time to visit them is early morning before 10:00 a.m. or so. Saguaros bloom late in the evening, producing copious nectar and pollen that attracts bats. Although the bats do visit and often pollinate the flowers, the blossoms remain open well into the next morning and are also visited by doves, several species of bees and other insects. Each flower blooms only for one day; a new crop of flowers will bloom every evening for two weeks or so.

Having a saguaro in your home landscape is a way to honor the desert lands we live in, and is also is a great conversation piece. Although a ten-foot tall saguaro is most spectacular, you do not have to spend thousands of dollars to have a saguaro planted in your yard. Most garden centers have small saguaros available ranging from six inch tall specimens for around $5.00 to taller plants that normally sell for $25.00 to $30.00 a foot. Or you can even “start from scratch” and plant saguaro seeds in your yard!

If you plant seeds or a young saguaro, choose a location that is partially shaded, such as beneath a palo verde or other large tree, which is where they would normally germinate and grow in the wild. Saguaros and other native cacti generally do not require special soil, fertilizer, or drip irrigation, although you will need to water any new planting at least once a week for a month or so to insure establishment. With proper care, a cultivated saguaro may bloom as early as fifteen years old. Even if you can’t stick around that long, planting a saguaro is a great gift to give back to the desert, and is also an enhancement to any neighborhood in the Phoenix area.

We Have Javelinas

March 2006
The Deem Hills are home to at least one small herd of javelina, also known as collared peccaries, who consider the neighborhood of Stetson Hills to be part of their territory. Mornings and evenings, the pack of peccaries comes down out of the hills to tour the suburbs, and perhaps to feast on succulent prickley pear cacti, mesquite pods, agave, or if they are feeling adventurous, a bowl of dog food!

Although they are more obvious when seen during their forays into the suburbs, a wild javelina can be incredibly difficult to spot among the desert scrub and boulders that make up their natural habitat in Arizona. During mid-day, when they are most commonly resting under trees or in shady alcoves, they can be indistinguishable from the gray shadows and rocks around them. But if you come too close for their comfort, they are most likely to bolt from their bedding spot, leaving a light musky scent in the air behind them. Where there is one javelina, there are often up to two dozen more, who all roam together in a distinctively scented herd. The special blend of musk from all of the herds’ members is rubbed onto one another, as well as being used to mark their territory.

Javelina are named for their small spear-like (or javelin) tusks that grow from the upper jaw of both sows and boars. Known also for their peculiar flattened heads, long bristley hair, poor eyesight, but keen senses of smell and hearing, these distant relatives of the domestic pig are common throughout the Sonoran and Chiricahuan deserts, and all of Mexico and Central America, where they also inhabit tropical rainforests. In fact, paleontological research suggests that peccaries evolved in rainforests, and have gradually extended their range to the southwest deserts. Archaeological evidence indicates that they did not inhabit our area until the late 1600’s. Winter weather limits their range further north.

Any time of year, a group of javelina may include a few youngsters, who are most often born as twins, and trot along with their mother within hours of birth. About the size of a cottontail rabbit, the one pound newborn piglets have reddish hair. Although the mortality of javelina is over 50% within the first year, those who make it beyond their youth may wander the desert for up to a decade. Humans, coyotes, bobcats, and mountain lions are their main predators.

As with most wildlife, javelina are more threatened by humans than the other way around, but to avoid any chance of unwanted aggression between you, your pets, and a frightened javelina, it is best to refrain from artificially feeding them, and to keep your pets’ food indoors as well.

Saturday, May 23, 2009

Spring Wildflowers

January 2006
Spring of 2005 was a banner year for desert wildflowers, making headlines on national news, and drawing crowds to our open spaces for a glimpse of color during what is mid-winter for much of the country. By mid-January a year ago, the Phoenix metro area had been blessed with weekly rains every week since mid-October, tallying well over the annual average of 7.5 inches. The soaking rains are the kiss of life for seeds of desert wildflowers which need a good six weeks of moist soils to germinate and grow strong enough to begin the annual flowering display by mid-January.

Here in the Deem Hills, we have some of the best annual wildflower displays in the area. No need to take a two hour drive to famed Pichaco Peak or 4-wheel into the Superstitions. A walk out your front door will easily lead you to bountiful slopes of poppies, lupine, owl clover, over four dozen other native species of annual and perennial wildflowers, and three dozen species of trees, shrubs, and cacti. One of the best areas to explore are in the saddle at the end of Deem Hills Parkway, between Stetson Hills and the new development of Stetson Valley. Another is along the Deem Hills ridge trail that that meanders along the crest of the preserve all the way up to the highest point at 2098 feet.

Alas, fall and winter rains thus far this season are on the drier end of the spectrum compared to last year, characteristic of the “boom and bust” cycles of precipitation in the Sonoran Desert. Still, you can count on discovering some wildflowers no matter how little rain has come. Hearty desert annuals will thrive with what moisture there is in refuges on the north sides of shrubs, trees and boulders. Perennials such as desert hyacinth and wild four-o-clock will have a shorter, less abundant display, but the fittest will survive to flower and set seed. Flowering shrubs like Brittlebush, Desert Lavender, and Ratany will always find energy to bloom, even if there is next to no rainfall.

Below are photos just a few of the species you are likely to find. For a full checklist of plants found in the Deem Hills, see the right-hand column of this blog page.
Phacelia (Phacelia crenulata)

Ironwood (Olneya tesota)

Fishhook Cactus (Mammilaria grahamii)

Ratany (Krameria erecta)

Desert Wishbone (Mirabilis laevis)

Desert Hyacinth (Dichelostemma capitatum)

Trails of Deem Hills

November 2005
When we first began shopping for a home in north Phoenix three years ago, a top priority on our list of “must haves” was “easy access to hiking in natural open space”. Along with “walking distance to good public schools”, “quiet”, and “neighborhood playground”, Stetson Hills was clearly a winner in all categories.

Before we actually made an offer on our home, we even took the time to test out the trails in Deem Hills. On a warm, rainy evening in October, we parked at the school and headed up Hackberry Drive and up into Deem Hills. The trail to the summit of the highest point was clear, save for a bit of scrambling over basalt boulders at the last pitch to the top. From there we surveyed the neighborhood below, nestled in the hills like a big easy chair. To the north, Pyramid Peak dominates the view, backed by layers of lavender hills. As we hiked down, the orange glow of sunset lit up the landscape, silhouetting the saguaros and lighting up the palo verdes. Perfect. A day later we signed our contract.

Since then, we’ve explored on and off trail all over Deem Hills. Although Deem Hills is a City of Phoenix Desert Preserve, so far there are no official trail maps. No worries! We’ve made one for you! Although some of the trails can become indistinct during the spring season when everything is growing wild, most of the year, you should be able to find the trails on our map. There are over 5 miles of trails total, which can take 3 or 4 hours to explore if you want to circumnavigate the Preserve. A quick morning jaunt up to the ridgeline and back can take less than an hour.

As with any desert hiking, it is best to wear good sturdy shoes, bring plenty of water, and wear sunscreen and a hat. Worried about rattlesnakes? In the many days that we’ve explored up there, we’ve never seen one, but we know they are there. Most likely, they will feel you coming and slither quietly away from danger (that’s you!). Do watch out for teddy bear cholla though. A pocket comb is a good tool to have along to pull out any cacti that “jump” at you, or hitch onto your shoes.

Please note that there is no parking at any of the trailheads on the Stetson Hills side. Fortunately, it’s an easy walk from your front door to the trails! Check the Stetson Hills website at to download and print your own copy of the Deem Hills Trail Map. See you up there!

The Three Little Shrubs

Up in the Deem Hills, and all over the Sonoran Desert, there are three dominant little shrubs, Brittlebush, Bursage, and Creosote. Each of them has to find a way to make a living in the hot, dry desert, where rain may be as little as 2 inches per year, and the air can heat up to over 120 F. By September, you would think any of these shrubs would just shrivel up and blow away. And they often do look like they are about to do just that!

The first little shrub, Bursage (Ambrosia deltoidea), the smallest and least widespread of the three, grows naturally in southern Arizona and northern Mexico. Bursage stays green year round, and has small, triangle-shaped leaves with soft hairs that reflect sunlight and help hold in moisture. When things get really hot, Bursage drops its leaves, and re-grows them after late summer and winter rains. Every summer, the sun beats down and says, “I’ll blaze and I’ll blaze, and I’ll dry you right up!” But Bursage keeps right on growing and flowering, and spreading seeds over the land.

The second little shrub, Brittlebush (Encelia farinosa), is a bit larger and more widespread shrub, growing out into the Mojave Desert of California. Like its cousin, Bursage, Brittlebush leaves are covered with soft white hairs that reflect sunlight and help hold in moisture, and when things get really hot, Brittlebush drops its leaves, and re-grows them after late summer and winter rains. But while Bursage just has simple green flowers, Brittlebush lights up the desert with beautiful yellow sunflowers each spring so that the hills appear to be covered in gold. Every summer, the sun beats down and says, “I’ll blaze and I’ll blaze, and I’ll dry you right up!” But Brittlebush keeps right on growing and flowering, and spreading seeds over the land.

The third and toughest little shrub, Creosote (Larrea tridentata), is the largest of the shrubs and grows throughout much of the desert southwest up into Nevada, west into California, east to Texas, and way down into Mexico. Creosote covers its leaves with a thin glaze that helps hold in water, and the tiny leaves can fold in half to further reduce water loss. Creosote sends down both deep taproots and spreads out long shallow roots, to absorb every last drop of water. After a good rain, the desert air is filled with the sweet smell of Creosote, and the shrub puts out a new crop of little yellow flowers. Every summer, the sun beats down and says, “I’ll blaze and I’ll blaze, and I’ll dry you right up!” But the Creosote keeps right on growing and flowering, and spreading seeds over the land.

In Stetson Hills, the people loved the three tough and beautiful little shrubs so much, that they chose them to decorate their greenbelts, parks, and roadways. As in the Deem Hills above, Brittlebush, Bursage, and Creosote continue to live where they always have, down here on the flats before all of the people’s houses were built. Thus, the three little shrubs go right on growing through the blazing hot summers, flowering, and covering the landscape with seedlings, even if the irrigation system dries right up!

The End