Thursday, December 2, 2010

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.

Sunday, November 28, 2010

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 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:

Wednesday, September 29, 2010

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
Western Bat Working Group

Friday, June 4, 2010

"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

Gopher Snake photos courtesy of Rick Halliburton.

Sunday, April 4, 2010

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!

Monday, February 22, 2010

Going Native: Plant Pairings for Your Home Landscape

If, like me, you moved to Phoenix from a cooler, wetter climate, adapting your ideas about what your front yard should look like to the Sonoran Desert can be challenging. Fortunately, there are plenty of resources to help you in the transition from a water-hogging bluegrass lawn and perennial flowerbeds to a beautiful desert adapted landscape. The first place to look for help is your big backyard, or the natural landscape that surrounds your neighborhood. The native plants that grow here are your best allies in designing a colorful, year round, low maintenance, and water efficient landscape.

The Deem Hills is home to over one hundred species of native plants, including six kinds of trees, twenty different shrubs, eight different types of cacti, five species of grass, two vines and more than sixty annual and perennial wildflowers. While some are more suitable for suburban landscaping than others, many favorites are commonly available at local nurseries, and are easily blended with other desert adapted species from the greater southwest deserts. In our own yard, I’ve established over eighty different plants that are native to North American deserts, two dozen of which are common in the Deem Hills.

A few good “pairings” will help you create a landscape that harmonizes with the surrounding desert and won’t croak when droughts take over or the drip system malfunctions!

Ocotillo and saguaro: The unusual architecture of ocotillo makes an excellent frame for the equally dramatic saguaro cactus. Little to no extra watering is necessary to keep these two desert icons thriving. Following spring rains, ocotillos will produce a fresh crop of green leaves and bright red flowers. If you don’t have the cash for a mature saguaro, you can still find a place for a young one anywhere from four inches to a foot high for less than twenty dollars. Saguaros also pair nicely with palo verde trees, which serve as their “nurse plant” in nature.

Brittlebush and barrel cactus: Soften the robust and spiny barrel cactus with a background of velvety blue-green foliage with brittlebush. The hearty native shrub will produce abundant yellow flowers in even the driest of years, and is easily pruned by snapping the stems.

Fairy duster and Parry’s penstemon: Put these together in place of a sugar water feeder and you’ll be sure to attract plenty of hummingbirds! Both bloom throughout the spring, summer and fall, adding bright red and hot pink to the garden palette.

Globe mallow and purple three-awn grass: The drought resistant globe mallow displays a range of sunset colored flowers from pale pink to deep orange. Purple three-awn is a graceful bunch grass with deep purple flowering heads and bright green leaves. Both of these natives are great alternatives to fountain grass and African daisies, both non-natives that tend to invade wildlands.

Poppies and lupines: Look for a desert wildflower seed mix that includes Mexican gold poppy (Escholtizia californica ssp. mexicana) and arroyo lupine (Lupinus sparsiflorus). Both are abundant in the desert islands of Phoenix. Be sure to sprinkle the seed in the fall (late October-November) so that they will germinate and bloom by February or March. Once these get established, they will seed themselves for future spring displays.