A Lizard with a Voice and More Monsoon Discoveries

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A few evenings ago, an uncommon view from my desk window engendered delight and a deep feeling of gratitude. The scene encompassed a wild mesquite bosque, standing tall and green in summer’s refulgence…a gentle, drizzling rain was floating its way to the ground, suffusing the air among the stout trees with the magic of a fine mist, colored soft in fading light. The land was coming alive, replete with the promise of sprouting plants, emerging fungi, and the rising scent of moist duff. A water-borne resurgence of desert life was in the making.

During the past few weeks, more rain has fallen, resulting in a cavalcade of change, a water-borne eruption of desert life. Flowers are blooming and creatures are stirring, many of which cannot be seen at other times of year. Giant millipedes are crossing roadways and threading their way through the woodlands, tarantulas are out of their burrows roaming the landscape, harvester ants are forming great clouds of alates bent on their one-day-per-year mating spree. Sonorous calls of amphibian passion are ringing through the night after every substantial rain. “Monsoon” as locals know it, is the one season that defines these lands and the ecology of southeastern Arizona more than any other. Arizona without its monsoon would be akin to Alaska without a winter. 

One of many creatures that are revealed during this season is a small, nocturnal lizard with semi-translucent skin like gauzy velvet, big eyes with vertical pupils and movable eyelids, and the very rare ability (among lizards) to vocalize. Once encountered, the western banded gecko is not soon forgotten. More than once, I have heard the word “cute” applied to this beguiling little creature that rarely grows to more than four or five inches in length and remains hidden during daylight hours. 

I discovered this little gem sheltering under an old piece of plywood. This banded gecko had lost its tail sometime in the past – the new one grew back lavender in color. A plump tail like this one indicates a good state of health, for the tail stores fats and water for the animal to draw upon during lean times, much like the tails of Gila monsters.

When predators chase after lizards, the first part of the lizard’s body that they make contact with is often the tail. In evolutionary response to this, many lizards have developed special abscission layers in their tails. Once contacted, the tail breaks off, leaving predators detracted by a wiggling morsel while the main course absconds to safety. Banded geckos have tails that break off with a very, very light touch; hence, I recommend against handling them.

When threatened or disturbed, banded geckos often curl their tails over their backs. Such posturing mimics the scorpions that they share habitat with, potentially scaring off some would-be predators. Banded  geckos can also utter an audible squeak when frightened, making them one of the few lizards in the world capable of vocalizing.

During late July, the mass of tadpoles in our bird pond (see the previous blog post) transformed into toadlets in a matter of only ten days. The tiny young amphibians are now hopping their way into the surrounding woodland, disbursing at night when temperatures are cool.

This minuscule toadlet was photographed during its first day out of its natal pond, where it had spent the initial ten days of its life as a wriggling tadpole. At this stage of their lives, Couch’s spadefoot toads (Scaphiopus couchii), are tiny and vulnerable, fitting easily atop a mere dime.

On a warm early morning in mid-July, I took a walk and discovered an abundance of white-lined sphinx moths (Hyles lineata) almost everywhere I went. Most sphinx moths do their flying at night, but these moths were out in direct sunlight. They were specifically targeting wolfberry (Lycium spp.) bushes. The wolfberry was in flower, and the moths were hungry for nectar. With unerring accuracy augmented by  rapid, graceful flight, they were moving from flower to flower, hovering at each one to insert their long tongues for sips of nectar.

A white-lined sphinx moth hovers over a wolfberry bush, deftly inserting its long tongue into the tiny white flowers to feed on nectar. Note the bend in the moth’s tongue, a common trait among many species of sphinx and hawk moths.

White-lined sphinx moths have a very wide distribution that includes most of the United States. In some areas, their tongues are considerably shorter. Here, as they coevolved with certain types of nectar-rich flowers bearing long corolla tubes, their tongues adapted over time.

Since the first of this year’s summer rains on June 18th, we have received 4.25 inches of precipitation. Here is an image of our bosque taken just before the first rains.

The same area, photographed yesterday. The difference is clear – the greening understory is composed primarily of pigweed (Amaranthus palmeri), a native plant that is of great value to a wide variety of birds and mammals. If the rains continue, this vivd understory will be capable of reaching heights of six to seven feet.

This is what is left of a pigweed plant that grew after last summer’s monsoon rains. Pigweed retains much value to wildlife even after it has died and desiccated to a state like this one. Note that the plant has been recently fed upon, and that the cuts at the tips of each stem are sharply defined, cut cleanly at a steep angle. This is a signature left by the incisor teeth of a black-tailed jackrabbit. Nearly all rodents and lagomorphs (members of the rabbit order) leave such distinctive cut marks when they browse on similar types of vegetation. If deer or javelina had done this, the cuts would be rough with frayed edges and not cut at such steep angles.

Our area, the Middle San Pedro Valley, is served by a single dirt road that frequently endures serious damage after monsoon rain storms. I photographed this large wash near our home shortly after dawn, several hours after the flood had crested. The wet marks along either edge reveal a surging flow of flood waters that had crested at over 150 feet in breadth and four feet in depth. Flows this strong are quite capable of quickly carrying away almost any vehicle, even very large trucks.

An Early Monsoon Photo Gallery

This year’s monsoon got off to an early start in mid-June, but thus far, we have received just 2.98 inches of rainfall. Many storms have passed by, missing us by only a few miles. Hope for more rain is justified, however, because the summer monsoon season still has a couple of months to go. Summer rain always brings a wonderful blooming of life to this arid landscape, most of which cannot be witnessed at any other times of year. Here is a brief gallery of some of those recent gifts…

The floor of the local mesquite bosque has been bereft of greenery throughout the autumn, winter, and spring. One of the first substantial monsoon storms brought color to the woodland floor – an effusion of fresh, young plants erupting from the soil. Also visible in this image are mesquite pods. Millions of these highly nutritious pods have fallen from velvet mesquites in the valley during the past couple of weeks, providing a keystone food source for a tremendous variety of pod-eating wildlife.

Rain cleans and wets the ground surface, providing a crisp, fresh record of the presence of local wildlife, like this mule deer buck’s trackway. As is the case with most quadripedal mammals, these tracks show substantial dimorphism: the larger track represents a front foot, the smaller a hind foot.

The remains of a well-chewed mesquite pod reveal the place where a rodent fed the night before. This one was most likely the work of an Ord’s kangaroo rat.

Tarantulas remain hidden and mostly inactive during much of the year. Summer rains bring them out of their burrows. This is a full-grown (palm-spanning) male Arizona blond tarantula, Aphonopelma chalcodes.

If I am not mistaken, these are western subterranean termites, Reticulitermes hesperus. After the first strong summer rain storm, these insects emerge in spectacular swarms to embark on their aerial, one-day-per-year mating flights. Termites are among the most essential of all insects in the desert southwest, for they are primary decomposers of plant materials, recycling essential nutrients back into the soil.

A western diamondback feeding on a lesser goldfinch at our bird pond. Some people may find this image disturbing, but such a viewpoint implies an abiological bias…the cute little bird and the horrible, scary snake. Both are native residents of this ecosystem, both are equally welcome on our property, and both must eat to survive.

An ornate box turtle, Terrapene ornata, stationed itself under a suet feeder one day and revealed something new – box turtles love to eat suet! Bits and pieces fall to the ground as woodpeckers and other birds feed on the suet block; these high-calorie morsels are eagerly consumed by other creatures, including ravens and nocturnally foraging mice.

A heavy rain brought several Couch’s spadefoot toads to our bird pond. Females are typically colored with dark reticulations like this individual.

Male Couch’s spadefoots are usually much more plainly colored.

A first! This morning, our “bird pond” was wriggling with new life, a batch of spadefoot tadpoles! If these tadpoles survive to grow into adult toads, they will carry the memory of their natal pond’s geographic location, and will return to it to breed in future years.

Another first for our bosque – a Gould’s turkey with young in tow. I had seen turkeys here before, but never a hen with her offspring.

At dawn’s first soft light after a nighttime storm, there were a dozen or more white-lined sphinx moths (Hyles lineata) circling the small pool of water that constitutes our bird pond. The moths were alighting to drink – they disappeared soon after, as daylight strengthened. These are large insects with three-inch wingspans, equipped with powerful musculature that enables strong, rapid flight. This species ranges from Central American northward to Canada.

A Gila Monster Rescued, Mating Rattlesnakes, and Images of Life Sparked by the Monsoon Rains

Arizona’s spectacular monsoon season is in full swing this year. Here in the Middle San Pedro River Valley, we have received 7.28 inches of life-giving rain during the past seven weeks. Life of all kinds is emerging, much of it empowered by this season alone.

The strikingly beautiful Gila monster pictured above was photographed by my wife Kathleen just days ago. (One more reminder to my readers: if you don’t see that image, it is because you are viewing this in your email. Always go to my blog site – https://ralphwaldt.com – to see this post as I intended it, without omissions.) It is one of many desert animals whose activity increases or otherwise changes as a result of monsoon weather.

The world we live in has been under deep duress this past year; the global pandemic, political division, economic hardship, and numerous worldwide catastrophes have all combined to make many people feel stressed and depressed. That is the anthropocentric world. A wider view – beyond the human-centric world that we pay so much attention to – encompasses the rest of the planet’s glorious and infinitely varied life. When I feel overloaded after viewing the day’s headlines, I can always find a source of solace, reassurance, and joy simply by abandoning the vicarious, shallow world of my computer screen in favor of the outdoor world. All it takes is a few steps outside. Sunlight, vivid green plants, lizards, trees, bird song, fresh air… the real world is medicine for the soul.

One does not need to live in a rural area like I do in order to tap into the natural world. I have a friend who lives in suburbia, along the fringes of the immensity known as Dallas-Fort Worth. He spends time in his backyard where trees, shrubs, and a garden bring life and happiness into his world. There are no bears, cougars, or Gila monsters in his yard like there are here – but there is a diverse variety of life. My friend focuses his attention on smaller creatures and other forms of life; insects, lizards, and flowering plants, for example. He photographs what he sees – things that most people never even notice. The photographs from his back yard are often stunning, revealing a world remarkably rich in life captured by a talented, artistic photographer whose sharp observational skills remind us that life is everywhere, and that life is beyond beautiful.

With those thoughts in mind, I offer a series of recent images taken during the heart of the monsoon season here in the Middle San Pedro Valley of southeastern Arizona…

My wife, Kathleen, encountered this Gila monster as it was attempting to cross a public roadway. She did the right thing – she pulled off the side of the road, turned on her hazard lights, and stood by, ready to usher the lizard out of harm’s way should a speeding motorist arrive on the scene. As the Gila monster made it safely off of the pavement, it turned to face Kathleen and her camera, then ambled off into the desert. The lizard was lucky this time. Large numbers of reptiles are killed on Arizona’s roads every day, many of them by people who are fast drivers and/or simply harbor callous attitudes towards reptiles. All it takes to avoid such losses is slower speed and a modicum of care for the life we share the planet with.

A single feather laying in front of our ramada had a story to tell: a great horned owl had landed there the night prior, likely as it pounced on a prey item.

Mornings that follow monsoon rain storms often reveal the nocturnal work of encruster termites. These tiny insects encrust plant stems (or in this case, mesquite beans) with a mixture of soil particles and viscous saliva, then feed on the encapsulated items. Termites are exceptionally important components of this ecosystem; they are very numerous, widespread, and perform a crucial ecological function by breaking down plant cellulose, thus returning essential nutrients to the soil.

Some two decades ago, I first tasted wolfberries – they were delicious. Native peoples gathered these berries as a seasonal food source. A large number of birds and mammals utilize them as a high-calorie-per-unit-weight food source, packed with natural sugars. This plant is of the genus Lycium.

Summer raindrops adorn the fresh blossom of an Arizona poppy plant, Kallstroemia grandiflora.

One of the valley’s most common summer wildflowers is also among its most beautiful; trailing four o’clock, Allionia incarnata.

The emergent blooms of a barrel cactus. These cacti rely on summer rains for their annual reproductive efforts.

Silver-leaf nightshade – Solanum elaeagnifolium – always a joy to encounter, this native plant is grouped in the same botanical family as tomatoes, but it is not safe for human consumption.

Tarantulas are common here, but can be seen with any frequency only during the monsoon season, when lower daytime temperatures and increased humidity bring them out of hiding. If left alone, these are harmless, innocuous creatures.

Caterpillars of the white-lined sphinx moth (and other native Sphingicampid moths) are very common sights during summers graced by monsoonal moisture. When mature, they reach a size approximating that of a person’s index finger.

A few days prior, I encountered this mating pair of diamondback rattlesnakes just outside my shop door. Courtship and mating in this species is a process that can go on for several days.

Another diamondback appeared here last week, a large individual. This snake is quite rotund in the latter half of its body – I’d guess that it was a gravid female. Snakes are a valuable asset here, for they are a major help in controlling rodent populations. Mice and rats in southern Arizona could win gold medals for their ability to get into vehicle engines, where they cause frequent and very expensive problems.

Puffballs sprout from the floor of our mesquite bosque with great speed after summer rainfalls. Puffballs are specifically designed to work with rain. First, an initial rain is required to soak the soil. This enables the spherical mushrooms to sprout above the surface. Puffballs quickly mature, then wait for the next rainfall to facilitate their reproduction. When raindrops impact a puffball, they cause a sudden increase in internal pressure, forcing thousands of minuscule spores to erupt (or “puff” like smoke) out of the hole in the top of the mushroom. By releasing its spores only in response to falling rain, the fungus assures that freshly moistened soil is available the enhanced survival and successful growth of its offspring. Pretty cool or what?

A Rare Pied-billed Raven, Giant Mites, an Insect Eruption, and a Tarantula for Dinner!

The four young Chihuahuan ravens that were hatched this spring in a  nearby mesquite tree have been exploring every nook and cranny of their expanding world. One of the four youngsters is a rare bird indeed, for it has a pied bill. (“Pied” simply refers to an object or creature that has two or more differing colors.) Both common and Chihuahuan ravens have black bills as adults. It will be interesting to see if this particular raven retains the pied colors on its bill as it matures into adulthood. The bills of its three siblings look quite different; they are well on their way to becoming fully black.

The young raven sporting a very unusual pied bill.

In comparison to any of its siblings, the pied-billed bird really stands out.

On the third day of July, this desperately parched, drought-stricken landscape received the first measurable rainfall in many months. Our rain gauge registered a total of 1.47 inches from two storms that arrived in the afternoon and late evening. Summer “monsoon” rains are an exceptionally important aspect of southeastern Arizona’s ecology. The summer rains spark a surge of new plant growth, enable many insects and amphibians to reproduce, feed the trees, recharge critically important aquifers, and much more. Life blossoms on this land after the gift of rain.

The “snowbirds” (part-time residents) who run out of Arizona every spring and scamper back in the winter never have a chance to experience the glory and magic of the famed summer monsoon season. So much happens in Arizona’s natural world during summer. Many creatures that are difficult or nearly impossible to see during the other seasons make special appearances during the monsoon. Among these creatures are red velvet mites.

Red velvet mites remain hidden underground during most of the year, where they seek refuge in silk-lined tunnels. Only after a summer rain do these giants appear on the surface of the ground.

The word “mite” should immediately conjure images of very, very tiny creatures. Most mites measure under a millimeter in length. Velvet mites (classified in the family Trombidiidae) are among the world’s largest mites. Some species approach one half inch in length; the one in the photograph is about a quarter of an inch long. They are nearly impossible to miss, as their brilliant red color contrasts sharply with their surroundings. Mites are very important constituents of soil fauna and thereby play essential roles in many terrestrial ecosystems. Some mites even have a place in human medicine. Oils extracted from one species of velvet mite native to India have been traditionally used to treat victims of paralysis.

photo caption: An emergence of thousands of winged termites from a gap between two cement slabs on the morning of July 4th, just after our first summer rain.

Every summer, on the first morning following the first substantial rainfall, termites erupt in synchrony by the millions from their subterranean dwellings in a united, landscape-wide orgy of reproductive zeal. Winged males and new, winged queens flood from their underground homes to take wing, mate, and disperse across the land. This event is one of spectacular importance, for termites are among the most essential and beneficial creatures in this entire desert ecosystem. They are primary decomposers, able to break down cellulose and thereby recycle plant materials into the soil. Without them, the health of this living landscape would be in serious trouble.

A closer look reveals a mass of gossamer-winged termites – new queens and males – known as alates. They arise from these masses in great numbers like curtains of smoke, dispersing, mating, and flying off to start new colonies. After mating, the insects lose their wings, structures that evolved for the sole purpose of dispersal and genetic interchange.

Monsoon rains also bring many other creatures out of hiding. Tarantulas are common here, but they are not easy to find except during the summer, when rains stimulate them to leave their burrows in order to forage and find a mate. These huge spiders are formidable, armed with a pair of long, sharply hooked fangs and stinging hairs on their abdomens. It is hard to imagine eating a spider that is large enough to fill the palm of one’s hand, but there are a few brave creatures here who regard tarantulas as dinner items…

Sonoran desert toads are common valley residents here along the San Pedro River. They are the largest toads native to the United States, reaching lengths of nearly eight inches. This rare image was photographed by a friend as the toad was in the process of ingesting a daunting meal, an adult tarantula.

There is more to the above  photograph than meets the eye. Frogs and toads possess remarkable viscoelastic tongues that fire from their mouths with great speed to catch their prey. Their tongues have a unique saliva that is phenomenally sticky; so sticky that some frogs in the genus Ceratophrys can haul in prey weighing more than themselves. This brings forth a question: how does a frog or toad get the prey item off of its sticky tongue once it is inside the amphibian’s mouth, so that it can be swallowed?

Alexis C. Noel, a Georgia Tech Ph.D. student specializing in biomechanics, published a scientific paper in 2017 documenting her research on the remarkable attributes of amphibian tongues and their saliva. What she discovered is physically, chemically, and biologically amazing…

Frog and toad saliva is a non-Newtonian fluid; the viscosity of the fluid can change based on how it is moved. When a frog’s tongue extends to impact a prey item, the saliva changes to a much more watery consistency, so that it can very rapidly coat the prey item and adhere to every part of the prey. As the impact slows to a stop and the tongue retracts into the mouth, the saliva returns to its normal thick, goopy consistency. This all happens in fractions of a second with incredible speed.

I recall watching many frogs and toads consume food items, mostly insects. Once the tongue returns inside the mouth with the prey item, the frog or toad retracts its eyeballs into its oral cavity, pushing the prey against the tongue. The push helps to release the prey from the tongue so it can be swallowed.