Thursday, May 1, 2014

Javelinas in the Hood

The signs are everywhere if you know what to look for: seedy piles of scat; hoof prints in the dust; large bites taken out of cactus pads; shallow depressions in the shade of mesquite trees and the occasional tuft of coarse dark gray hair. If you have a good nose, you might smell their peculiar musky scent. Collared peccaries, better known as javelinas, are frequent visitors to many suburban neighborhoods in Arizona. However, unless you are nocturnal like they are, actually seeing one is quite rare.

Stetson Hills resident, Jennifer Moore, was once woken at 2:00 am by the sound of snorting and huffing outside her open window. When she looked out to see what was going on, there was a herd of eight javelinas trotting single file down the sidewalk. Another neighbor regularly sees them very early in the morning outside their view fence as the animals make their way to daytime shelters under nearby palo verde trees. A more recent report came from a neighbor who witnessed a pack of coyotes gorging on the carcass of a large javelina boar along one of the neighborhood trails.

Suburban habitats around Phoenix provide a smorgasbord of some of the javelina's favorite foods, including jojoba nuts, acorns, cactus fruit and pads, mesquite pods, agave, plus flowers, fruit and bulbs. Like their distant cousins, wild boars and pigs, javelinas are opportunists, so will happily eat your garden tomatoes, squash, birdseed or a bowl of dog food. By night they may be munching in  your yard, but during the day they will retreat up washes into the desert where they can rest unseen until the sun goes down. The Deem Hills are home to at least one small herd of javelinas that considers the neighborhood of Stetson Hills to be part of their territory.

They are named for their small spear-like, or javelin-shaped, tusks that grow from the upper jaw of both sows and boars. Also recognized by their peculiar flattened heads and long "collar" of bristly white hair, javelinas are reputed to have very poor eyesight, but keen senses of smell and hearing. They are common throughout the Sonoran and Chihuahuan deserts, all of Mexico and Central America and down into Argentina where they also inhabit tropical rain forests. In fact, paleontological research suggests that javelinas evolved in rain forests and have gradually extended their range to North American deserts. Archaeological evidence indicates that they did not inhabit northern and central Arizona until the late 1600's. Severe winter weather limits their range further north.

Javelinas are one of the few large wild mammals that breed year round, so it is not unusual to see pairs of tiny, red-haired piglets scampering to keep up with the rest of the family. About the size of a cottontail rabbit, the one-pound piglets are ready to run within a few days of being born. Although the mortality rate for javelinas 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. Although javelinas are generally gentle animals, they do have a reputation for being aggressive defenders of their young. In any encounter with wildlife, it is best to not get between a mama and her babies!

As with most wildlife, javelinas are more threatened by humans than the other way around. To avoid any chance of unwanted aggression between you, your pets and a frightened javelina, refrain from artificially feeding or watering them, and keep pet food indoors.

Wednesday, February 5, 2014

Blackbirds: Pastry Surprise or Avian Pirates?

"Four and twenty blackbirds baked in a pie" is one of the more memorable lines in nursery rhymes passed on from eighteenth century England. There are many interpretations of this verse, but the two most cited are that there were actually recipes for live birds to serve as surprises at royal banquets; or that the entire poem is a secret code advertising for crewmen to contract with Blackbeard's ship.

In Europe, where this poem originated, one of the most common "blackbirds" is the starling, which was imported to North America in the 1890's as one of the menagerie of over sixty bird species mentioned in Shakespeare's writings. (The bard's play, Twelfth Night, is the oldest known source for the line "Sing a song o' six pence.") On many spring mornings, you might see starlings grazing local lawns and parks along with flocks of several types of North American blackbirds, which include cowbirds, grackles, Brewer's blackbirds, as well as the more colorful yellow-headed and red-winged blackbirds. This is especially true in winter months, when many birds congregate in mixed flocks while feeding.
Female grackles                                                        photo by Rick Halliburton
In the official blackbird family, Icteridae, males and females are often mistaken for completely different species because they look so different. Females' feathers are designed for camouflage, dressed in drab brown rather than black. Showy males are up to 60% larger than females and wear sleek black feathers with sheens of blue, green and purple. Blackbirds tend to thrive in the company of humans in both agricultural and urban settings, often in noisy flocks of hundreds, thousands or even millions. Because of this, they are often considered to be "pests," but there is also much to appreciate about blackbirds.
Male grackles in courtship displays                      photo by Rick Halliburton
The most elegant of this group are the male Great-tailed Grackles, with long fan-shaped tails, iridescent feathers and bright gold eyes. During their breeding season, the males perform ardent courtship displays featuring neck stretching, wing vibrations and tail fanning, accompanied by loud screeching and cackling. Some of this is competitive, so you'll sometimes see several males displaying at once as they vie for their rank in the local mating hierarchy. Both males and females are promiscuous, meaning that they all have multiple partners, although there tends to be more available females than males in most colonies. In this species, the ladies take care of nest-building and chick-rearing on their own. Thus, in some Hispanic cultures, a lazy husband who doesn't work is called a Zanate, one common name for a male grackle.

However, it is not completely derogatory to be called a Zanate, for they are also known as great vocalists. According to a Mexican legend, the grackle's diverse repertoire of whistles, chattering and squawks is said to represent songs expressing the Seven Passions of Life: love, hate, fear, courage, joy, sadness and anger.

Although the meaning of the nursery rhyme is ambiguous, one thing is for sure: if you take the time to watch a flock of blackbirds in their amazing synchronized flights, listen to their songs, or watch their elaborate courtship displays, you are sure to feel one of life's passions: joy!

Wednesday, January 1, 2014

From Down Under: Wattles, Kurrajongs & Gum Trees

Eucalyptus at a Phoenix golf course
One of the curious things about Phoenix is that there are more species of plants in the urban area than there are in the immediately surrounding Sonoran Desert. This is because we have imported hundreds of plants from other parts of the world. One of the highest-ranking countries for floral immigrants is Australia, with over eighty species of trees and shrubs that are cultivated and sold in garden centers all over the southwest. Since the interior of Australia is a desert very similar to central and southern Arizona, the plants adapt quickly to our equally hot, arid and sunny climate. A walk around the block of suburban neighborhoods around Phoenix is bound to take you past many Aussie ex-pats, especially wattles, gum trees and kurrajongs.
What wattles are to Aussies are known as acacias in North America. They all belong to the pea, or legume, family, but Australian acacias lack the spines or thorns that serve as self-defense from browsing mammals in North American ones. In place of thorns, the leaves of wattles contain alkaloids that are toxic to most animals. Over nine hundred of the world's thirteen hundred Acacia species are native to Australia. The most popular ones used for landscaping around Phoenix are the slender-leaved Willow Acacia (A. salicina) and Shoestring Acacia (A. stenophylla), both of which fill the air with sweet perfume from the puffball-like flowers every fall.
Kurrajong is the Australian aboriginal name for the bottle tree, a stout tree named for the shape of its trunk. The hard brown seedpods look like little canoes and the speckled maroon and white flowers resemble tiny jester caps. Indigenous people still use the bark of the tree to make fishing line, which is what "kurrajong" means in a now extinct language once spoken near Sydney.
Perhaps best known of the Australian flora are gum trees, or Eucalyptus, famed home of the kookaburra, a type of giant kingfisher. Just fifty miles west to Phoenix near Tonopah, Australian Outback boasts that it is "the worlds most extensive Eucalyptus browse plantation," providing North American zoos with leaves for captive koalas, which feed almost exclusively on Eucalyptus. There are seven hundred species in the world, and all but fifteen are native only to Australia. Here in Phoenix, around forty species are available through the garden trade. gum trees are revered for their beauty, shade and as fast-growing trees that provide wind breaks and screening in agricultural and industrial areas. That is why rows of eucalyptus are commonly planted along our roads and freeways and other not-so-scenic parts of the city, which is just about everywhere! Gum trees also make excellent pulpwood; the soft fibers are especially useful for making tissue paper. You probably have rolls or boxes of eucalyptus-based papers in your bathroom! In your medicine cabinet too, you may have throat lozenges, toothpaste or other cosmetics that contain eucalyptus oil.

Although it would be difficult to support a population of koalas in Phoenix gum trees, many native birds and insects have adapted to using them for food and shelter. most notably, monarch butterflies will roost and feed on Eucalypts during their annual migration. This is especially prevalent along the coast of California, where hundreds of thousands of monarchs roost during the winter months. In the annals of evolutionary biology, rapid adaptive responses to recently introduced species are a unique crucible for speciation. On the other hand, some people view any non-native species as a pest that interferes with the natural order of things, so many eucalypt forests are targeted for destruction, especially since they are also fire and windfall prone trees.

However, a special Red Gum (E. camaldulensis), affectionately known as "Mr. Big," is well-guarded and cared for not far from Phoenix at the Boyce Thompson Arboretum in Superior. The giant is reputed to be the National Champion of its kind, running neck and neck with a specimen in California at over one hundred forty feet tall and over six feet in diameter. Equally notable is Mr. Big's stats as the State Champion of all trees for height in Arizona, topping the runner-up Ponderosa pine in height by over thirteen feet!

Sunday, October 13, 2013


If you had lived among the Hohokam people in this area hundreds of years ago, you would have looked forward to a bountiful harvest of hornworms at the end of monsoon season. The edible hornworms are the caterpillars, or larvae, of white-lined sphinx moths (Hyles lineata), and are named for a short spine protruding from their rear ends. This year, thousands of these fat, green caterpillars were seen along desert trails and city streets wherever there was an abundance of their favorite food, a sprawling annual plant called spiderling (Boerhavia spp.).  On the autumn equinox, there were so many trying to cross the road at Happy Valley and 33rd Drive that some sections of asphalt turned a lovely shade of chartreuse. If you were lucky enough to see them up close, you might have admired the colorful pattern of black and green stripes, accented by red spots along their sides, one of nature's most colorful works of art deco.

Still today, some indigenous people of southwest deserts gather and dry bushels of hornworms for food. In southern California, the Cahuilla people call them "piyatum." O'odham people of southern Arizona named the host plant "makkum jeej," which means "mother of the caterpillar." If you are going to try this local delicacy, it's important to pinch the head off and shake the guts out before you skewer them on a stick to roast over hot coals, according to one 19th century ethnographer who learned piyatum foraging skills from the Cahuilla. 

Lizards and birds also feast on hornworms, dead or alive, head, guts and all.

These finger-sized caterpillars are just one stage in the life cycle of an even more fascinating and beautiful moth. After they have eaten their fill, hornworms burrow into the soil and change into a brown, pod-like pupa. This resting stage varies from two weeks to six months, depending on the time of year and latitude where they live. During this time, the caterpillar transforms into a moth, a mysterious process still not fully understood by scientists. 
Longer days of spring induce moths to emerge from the pupae after spending the winter months underground. Pupae are able to perceive light and therefore, the number of hours of sunlight in a day. Here in central Arizona, there may be several cycles of metamorphosis between March and September, with moths emerging within two weeks of pupating. Additional environmental cues, including soil temperature and moisture, ensure that pupae remain underground so that the moth's emergence will coincide with flowers to feed on and the right kind of plants to lay eggs on so that caterpillars will have plenty to eat. This is a well-orchestrated miracle!

Since moths are mostly crepuscular (a fancy term for being active during shadowy hours of dawn and dusk) or nocturnal, they favor white flowers, which are more visible in low light. They are also strongly attracted by certain floral scents. Their super long tongues allow them to slurp up nectar from deep-throated flowers like evening primrose, jimson weed, columbines and night-blooming cacti. In the process, their furry bodies are dusted with pollen, which gets transferred to other flowers as they go about foraging, making them important pollinators for some species. 

As adaptable opportunists, white-lined sphinx moths often fly in broad daylight and will feed on any color of flower that has sufficient nectar. Their adroit hovering skills and rapid wingbeats make it easy to confuse a sphinx moth for a hummingbird at first glance, but the brown and white stripes on their wings and flash of orange on the underwings are unlike any hummingbird. During a moth's two to three weeklong life, their primary mission is to mate. Females may lay hundreds of eggs that hatch within a week or so to begin the cycle again.

This is all really interesting, but after consulting with several entomologists and texts, I'm still left wondering: "Why do caterpillars try to cross the road?" Is it just to get to the other side? And is it true, as some naturalists claim, that they tend to crawl north? It turns out, no one really knows. The caterpillars are probably looking for more food, or soft soil to burrow into. But wouldn't the vast corridors of hot asphalt deter them from what is almost always a suicidal journey? Fortunately, although we may notice them mostly on roads, there is still plenty of desert land for hornworms to inhabit without having to navigate through heavy traffic. 

Wednesday, August 7, 2013

Toad Season

Couch's Spadefoot                                                Photo by Rick Halliburton
If you're looking for unique entertainment on a hot summer night, consider planning an evening out to listen to the local toad choir. WIthin 24 hours of a major rain event, desert toads will emerge from their underground dens and hop for up to a mile in search of a pool of water to breed in. The best seats in the  house will be near one of these warm pools during the first few nights after the storm. If you miss the post monsoon concert, tadpoles and toadlets will provide daytime entertainment for at least a week or two. 

A chorus of toads may include up to five species in our area, each adding their own rhythm and pitch to the performance. All of the choristers are male, ardently singing to attract mates. Couch's spadefoots bleat like lambs. Red-spotted toads trill. The Sonoran Desert toad adds a loud intermittent "Squawk!" and Great Plain's toads will chime in with a persistent jackhammer backbeat. If Woodhouse's toads are about, they'll croon a loud "Waaaaaah!"

Of these, Couch's spadefoots are the most common in the suburbs of Phoenix during monsoon season. Spadefoots, named for the tiny digging tools on the bottoms of their hind feet, are cued to emerge not by moisture, but by staccato drumbeats of hard rain and vibrations of thunder. The opportunity to mate is the primary motivation for toads to wake up from nearly a year of dormancy buried in the earth up to three feet below the surface. Eating comes second. 

At this end of the Valley, Skunk Creek, New River, and Cave Creek are excellent venues for toad concerts. "Creek" and "river" are deceptive names for these usually dry washes that may only flow for a few days a year. But an inch of rain anywhere upstream in the watershed can transform a wash to a raging torrent in a matter of hours. When the floods settle down, the pools left behind become toad nurseries. 

Spadefoots are famous for being one of the most rapidly developing amphibians in the world. One lady Couch's spadefoot can produce over 3,000 eggs that will hatch within a day of being fertilized. Then the race is on for tadpoles to develop into toadlets before the pond evaporates. If they don't get eaten, they can hop out of the pond within eight days. After surviving that challenge, a toadlet must then navigate the world of terrestrial predators, which includes lizards, snakes, raccoons, birds, other toads, and even spiders. Of thousands of eggs, perhaps one percent will live the two years it takes to become a breeding adult. These lucky survivors may live up to ten or more years in the wild. 

Many amphibian species around the world are suffering severe population losses due to a suite of factors, including habitat destruction, fungi and water pollution. "Toads that are adapted to temporary ponds in the Sonoran desert seem oblivious to these threats," notes herpetologist Brian Sullivan, a professor at ASU. He's been studying populations along Skunk Creek and Cave Creek for over three decades and sees no sign of decline. "There is, however, plenty of variation between years, as is expected in a climate like ours," he explains. "Successful breeding happens about one in five years, which is about how often the monsoon pools will last long enough for tadpoles to develop into toadlets."

Even with the abuses of road construction, flood control dams and off-road vehicle recreation, some of the washes in suburban areas remain excellent habitat for toads.  "There is always something fascinating going on in suburban desert washes," Say Randy Babb, herpetologist at the Arizona Game and Fish Department. For Babb, toad season is a favorite time of year. "I highly recommend that folks turn of the TV, abandon your computer, and get out to witness one of nature's coolest miracles," exclaims Babb.

Tickets are free!

If you’d like to identify toad songs you hear at your next toad concert, log onto the Reptiles and Amphibians of Arizona website to hear recordings:
Arizona Game & Fish Department also has some excellent videos of local toads at their website:

Warning: Handling any toad may cause an allergic or toxic reaction in most people as well as dogs who try to eat them. Neurotoxins are secreted from a toad’s parotoid glands, a pair of lumps behind their eyes. However, you do not have to worry about getting warts from handling toads. 

Friday, June 21, 2013

Bean Trees

For one-stop shopping in the Sonoran Desert, a mesquite tree is your best bet to find everything you might need, whether it be food, fuel, building supplies, medicine, rope, and yes, even diapers. These trees were so valued by traditional cultures in the southwest deserts that families claimed certain mesquite groves, or bosques, as well as especially productive individual trees, as their territory. One mature tree may produce between 40 to 100 pounds of bean pods in a good season, the basis of a healthy diet for many tribes. The pods were stored through the winter and ground into flour when needed to make cakes, porridge and sweet drinks throughout the year. For thousands of years, desert people have gathered mesquite wood for building shelters and making fires, sap for dyes, roots for fiber and leaves for medicinal tea. The diapers were made by pounding sheets of the fibrous bark into a soft cloth that would absorb any “leaks.”

The human relationship with mesquite is not quite so benevolent everywhere it grows, however. Many ranchers consider it to be a pest, since it will thrive wherever cattle roam, replacing valuable grasslands. The irony is that cattle feast on mesquite pods, and then deposit the beans in cow pies, a perfect environment for the seeds to germinate and grow.  Thus, more cattle on the range is better for mesquites. Paleontologists have deduced that cattle may be replacing the role of other large mammals that once roamed the southwest, such as camels, giant sloths and mastodons. After the Pleistocene extinctions about 10,000 years ago, mesquite bosques contracted to waterways and washes, where year round moisture and seasonal flooding ensured their success. But without passage through the guts of large mammals that travel long distances between waterways, the seeds were no longer distributed onto uplands.
Even though a healthy bosque provides shade and fodder for cattle, an aggressive campaign to eradicate mesquite in favor of grasslands ensued through the 1900’s. Combined with habitat destruction for agricultural, industrial and urban development, plus harvesting of trees for firewood and lumber, wild mesquite bosques are now considered somewhat rare.
Fortunately, the versatile bean tree has become a popular landscaping species over the past few decades, and is now grown and planted widely through the arboriculture trade. Velvet mesquite (Prosopis juliflora) is the most common in the Phoenix area, shading many parking lots and suburban tracts with their graceful, contorted stems. The return of mesquite to urban areas is also a boon to wildlife. Rabbits, coyotes, quails, javelina and deer also feed on the bean pods. Dozens of bird species nest and forage for insects in mesquite limbs. Mesquite leaf letter enriches soils with nitrogen, which, combined with shade, makes them excellent “nurse trees” for many kinds of plants. Plus, over sixty species of insects have been documented as visitors to mesquite flowers, gathering the abundant pollen and nectar to propagate their own offspring. In the spring, when long tassels of flowers dangle from the branches, a bean tree literally hums with life.  
According to the locavore food movement, which promotes the use of regionally adapted and native foods, mesquite could be the key to a more abundant and nutritive future for desert dwellers. If you are lucky to have a mesquite in your yard, you can rake up the pods to use as an alternative to mesquite wood for grilling and grind them into flour to use in baking. Here's how:

Prepare bean pods: Collect and rinse pods with clean water and dry in the sun. You can accelerate drying by putting them in the oven at the lowest temperature (~150F) for 2-4 hours. The more crispy the pods, the easier it is to grind them into flour.

Make the flour: If you want to be very traditional, get out the mano and metate or a mortar and pestel! However, you can also grind the bean pods in a blender. Just  put about 15 pods in at a time for about 30 seconds. Sift with a fine sieve and store the flour in the freezer until ready to use. Make sure you are sifting out the hard, bitter seeds.

Bake: The traditional cake or cookie was a simple mixture of flour and water, made into round flat patties and dried in the sun. To use mesquite in baking, just replace ¼ of the amount of flour called for in your recipe with finely ground mesquite meal.

Steep Tea: A sweet tea can be made by soaking some of the flour in water and then straining off the pulp….perfect to serve with cookies!

To learn more about the history and ethnobotany of mesquite, look for these books:

Gathering the Desert by Gary Paul Nabhan

Medicinal Plants of the American Southwest by Charles W. Kane

And check out this website: Desert Harvesters ( in Tucson hosts mesquite pod milling events every year, as well as being a resource for numerous workshops and publications on native plant foods.

Monday, April 15, 2013


If you were to choose sounds that best represent the “Wild West,” the howl of a coyote would certainly be in the top 10, if not number one on the list. Whether it’s the song of a lone coyote or the frenzied yipping of a small pack, their voice elicits strong emotions from anyone who hears them. Indeed, coyotes are some of the most admired, hated, respected, feared, romanticized and misunderstood wild animals in North America.
            Unlike wolves, their larger canine cousins, coyotes have a remarkable ability to adapt to human activity. Equally at home in urban areas, agricultural regions and remote wilderness, coyotes are similar to people in many ways. Both clever opportunists and formidable predators, they are omnivorous and will eat almost anything that is made available to them. Like indigenous people of the Sonoran desert, their favorite foods include mesquite beans, cactus fruit, cottontails and quails. Unfortunately, some coyotes in rural areas have, like humans, developed a taste for lamb, beef and venison as well, and are thus perceived as serious competitors for food.
            Although there are no official population estimates, urban wildlife specialist Darren Julian of the Arizona Game and Fish Department (AZGFD) says that there are more coyotes per square mile in suburban areas of Phoenix than in the surrounding desert regions. “They are especially common near golf courses and lake communities, or in neighborhoods where there are greenbelts. These areas support a lot more prey animals, such as cottontails, doves, and small rodents,” says Julian. “There is no true drought experience in the suburbs, so there is plentiful food year round for all kinds of urban predators, which includes owls, bobcats and foxes, as well as coyotes.”
            The abundance of prey near irrigated lands, whether agricultural or suburban, makes these ideal places for coyotes to raise families. April and May is prime time for coyote pups, so both parents are hunting for three or four, rather than just themselves.  At about six months of age, pups will be out hunting on their own.
Photo by Ruth Anne Kocour
Coyotes are usually seen trotting through the neighborhood alone, but occasionally travel in family groups of up to five or six, especially in the fall when pups are still being schooled in the art of hunting. Fall and winter, from September through January, is also when they are most vocal, since there are more rowdy “teenager” coyotes, and individuals are often calling to keep track of each other.  Things are a little quieter when they are denning with young pups in spring and early summer.
            Many people fear coyotes, but the coyote has much more to fear in humans. AZGFD records show that between 30,000 and 40,000 coyotes are killed by hunters each year in Arizona alone, primarily for recreational purposes.  This is a sharp contrast with the reverse statistics, with only 2 fatal and fewer than 200 documented non-fatal attacks by coyotes towards humans in the entire United States and Canada over the past 30 years. Although coyotes do occasionally prey on small pets and livestock, those numbers are in the low hundreds each year for Arizona.
            The best way to avoid unwanted interactions with any wild animal is to not provide them with food. This means that pet food and small pets should not be left unattended outdoors, and birdseed or other food sources that attract prey species should not be made available near your home.
            Otherwise, consider yourself lucky if you see a coyote on the trail or in the neighborhood. They are part of a healthy ecosystem, helping to keep rodent populations in check and providing the bonus of a little night music.  If you can’t hear them at night out your window, you can listen to them howling on-line here: Wild Coyote Sounds 

Learn more about urban coyotes at these websites: