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, www.azgfd.gov/urbanwildlife, 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!

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 http://geoplan.asu.edu/aztc/monsoon.html

SEED-LOVING SQUIRRELS

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.

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.

Roadrunners

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 www.reptilesofaz.com.