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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.
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.
It has been a very long time since I posted a new entry on this blog. I feel that I owe my readers an explanation. Why no new blog posts? I have been deeply depressed for months – and depressed writers don’t write. In terms of what has been causing this lasting depression, it is a small avalanche of things…the unjustified furor over the most recent presidential election. The insurrection – one of the most unpatriotic acts I ever known to mar my country’s history. The widespread denial of science by millions of Americans. The pandemic – ranking the United States as the world leader in Covid deaths – an inexcusable national embarrassment. Mass shootings -another ghastly national embarrassment, as we lead all other nations on Earth by a very wide margin with respect to such violent, maniacal acts. The mounting gullibility of our populace coupled with a concerted effort by millions to divide a great nation. The horrific war in Ukraine…and there is plenty more, but I will keep the rest private.
As it has been throughout my life, the world of nature has been a source of peace, calm, reassurance, and sanity during these deeply troubled times. I am so grateful to live far away from towns and cities in a rural setting where birdsong, wildlife, a lack of crowding, and sunlight feed my soul.
So, what is going on in the Middle San Pedro River Valley lately? The landscape is very dry, even by desert standards. The usual winter rains were both scarce and weak, resulting in an entire region whose mesquite bosques sprouted no green understory plants, a valley floor bereft of the normal growth of winter grasses, perennial reaches of the river receding, and uplands nearly devoid of spring wildflowers.
The bright crimson fruits of Christmas cactus, Cylindropuntia leptocaulis, bring color to a desperately dry landscape. This species is of special benefit to wildlife, for it retains these nutritious fruits throughout autumn, winter, and into the following spring, even in a very dry year like this one. Indigenous peoples made common use of the fruits of this cactus as a food source.
As far as avian life goes, I have never witnessed such a paucity of birds here, both in terms of species diversity and numbers. Numerous migratory species, birds that I have regularly observed every spring for 20 years, simply did not appear, or appeared in very low numbers. There were no back-throated grey warblers, no orange-crowned or Virginia’s warblers, no Empidonax flycatchers. I recorded the presence of only one Townsend’s warbler during migration, and there were startlingly low numbers of normally abundant yellow-rumped warblers. Rufous-winged sparrows, a common fixture here, are entirely absent from our property this year for the first time ever. On the positive side of things, we now have three dazzling male varied buntings visiting our water dishes daily, two more than any other prior year had provided. Our resident ravens, Mike and Mavis, hatched out a clutch of four a few months ago, just 100 feet from my office window. That brood fell victim to a group of coyotes on the very first night that they left the nest. The determined parents have since built a new nest on a nearby property, a place where the landowner is very appreciative of the local wildlife. Mavis is busy incubating her second clutch of eggs in a safe place…
Even the local reptiles – especially the snakes – have been few and far between this summer. A few weeks ago, one of our local diamondbacks appeared at our bird pond to drink and grab a feathered meal or two.
This western diamondback – a familiar individual – appeared in May, visiting our bird-watering pond.I have come to recognize several of the rattlesnakes whose ranges include the area close to our buildings. My sharp-eyed wife pointed out the distinctive, fused blotches on this snake’s tail. With close observation, nearly all rattlesnakes can be recognized as distinct individuals – the patterning and shape of the blotches on the back, and especially markings on the heads and tails of rattlesnakes make it possible to readily identify individuals.I have seen diamondbacks lay in wait at the edge of our little pond, but very rarely do I see them partially submerged like this.
During the hot months in southeastern Arizona, any water source attracts wildlife of all sorts. Simply maintaining a few water dishes does wonders for throngs of very thirsty birds, reptiles, mammals, and more. Our “bird pond” is nothing more than a shallow depression dug into the ground, fed by a trickling garden hose; very simple to set up and maintain. It would take pages of text to tell all the tales of the remarkable diversity of living creatures that have availed themselves of this water source over the years.
Box turtles have come out of hiding. This one waded into the shallow pond to cool off and rehydrate itself via some long drinks.A herd of well over 20 javelina visit here daily – here a mother drinks water from the pond while her youngster suckles milk.
Last, but surely not least, as I began to assemble this new blog post on the evening of June 10th, raindrops began pelting the roof! This was no “teaser” rain, no ten-second-this-is-all-you-get rain, but a prolonged rain that wetted the dusty ground and left small puddles in its wonderful wake. This is a rare event, so early in June. Desert life benefits from the gift of every precious drop.
For many living things, effective camouflage often means the difference between life and death. I have witnessed camouflage acts that left me amazed – snowshoe hares in winter, whose fur matched the color and reflectivity of snow perfectly, or the disappearing act of a snipe crouched in grass…but lately, I witnessed a larval insect whose camouflage made my jaw drop.
One of the strangest caterpillars I had ever seen…
The creature had brashly exposed itself by falling from its perch in a velvet mesquite tree to land on a hand railing that had been painted white. It had gone from near invisibility to “How could you possibly not see me?” in the blink of an eye. Clinging to the railing was a slow-moving, two-inch caterpillar cryptically colored with dull greenish-gray skin. Hair-like filaments extended from its prolegs to form a peripheral fringe around the caterpillar’s body. The filaments served to effectively break up its outline. As if that were not sufficient, the crypsis of this larval moth went a step further, for the caterpillar’s body was quite flattened. In cross section, most caterpillars are round or somewhat ovoid, but this one had a cross-sectional shape more like a thin, gently curved crescent. This unusual shape meant that the dull-green, fringed caterpillar could literally melt into a twig or a branch to cloak itself in obscurity like a ghost in a fog bank.
Later, some research revealed that the creature in question was a lappet moth caterpillar, possibly of the genus Gastropacha. The word “lappet” is used to describe a fold or flap in a garment or headdress. Thus, lappet moths (family: Lasiocampidae) get their name from the hair-like fringes that project from their larvaes’ prolegs.
A lappet moth caterpillar that had fallen out of its element – transformed from profound obscurity to blatant visibility.
During the autumn of 2021, discoveries here in the surrounding mesquite bosque included this banded gecko that had dropped into an old bucket. These velvet-skinned reptiles are common here, but remain well hidden and inactive during daylight hours. Geckos are among the few truly nocturnal constituents of Arizona’s rich saurian fauna. I found this young glossy snake hidden beneath an old piece of plywood on the ground. Glossy snakes are often mistaken for gopher snakes. These beautiful, innocuous reptiles can reach lengths of nearly five feet. They are among this area’s most common serpents. Their scientific name is a gem: Arizona elegans.
The 2021 monsoon brought a cavalcade of change to the Middle San Pedro Valley. Late in autumn, large numbers of Empress Leilia butterflies (Asterocampa leilia) could be seen adorning the landscape. Abundant rainfall spurring rapid growth of their food plants likely played a major role in the eruption of these insects. Their caterpillars feed on desert hackberry, Celtis ehrenbergia (formerly pallida).
Take a walk in a local bosque late in late autumn and you are likely to see what look like little clumps of snow in the distance, gleaming white patches that really stand out on the dark-colored floor of the woodland. A closer look reveals a surprise; a mass of seeds from an unusual member of the dogbane family known as climbing milkweed, Funastrum (formerly Sarcostemma) cynanchoides. Unlike most other types of milkweed plants, climbing milkweed is a true vine, ascending to heights of 10-12 feet in tall shrubs and trees.
It is hard to miss the contrast between a clump of climbing milkweed seeds and the floor of the bosque.
After pollination, the flowers of climbing milkweed form pods that eventually fall to the forest floor, where desiccation causes them to split open and unfurl a beautiful array of seeds embedded in a mass of gleaming, silvery-white filaments.
A closer view reveals numerous seeds, the future of the species encapsulated within each one. Climbing milkweed is a host plant for the larvae of both queen and monarch butterflies.
Individual seeds can be carried long distances by wind currents, effectively distributing the plant’s progeny across the landscape. Wide distribution of seeds enhances the probability for successful germination and the continued success of the species.
The 2021 monsoon season in southeastern Arizona has certainly been one of the most memorable. At our home acreage in the Middle San Pedro Valley, 9.81 inches of rain have graced the land since the rains began on the second day of July. Other locations within less than 40 miles of us have received over 16 inches! The result is a landscape – and an ecosystem – burgeoning with a refulgence of renewed life. Since regional records have been kept, only the 1955 and 1964 monsoon seasons can compare. The scene above, featuring a landscape bursting with fresh, vivid green growth crowned by a rainbow is emblematic of Arizona’s monsoon.
As the monsoon wanes, migrant birds visit our feeders and watering places; notable appearances this year have included large numbers of Nashville warblers and an exceedingly rare blue bunting, a species that has never been “officially” recorded anywhere in Arizona. As the season approaches autumn, many changes occur in the world of reptiles and insects as well. Rattlesnakes are moving toward their hibernacula sites. The year’s last generation of butterflies brings flashes of beautiful color to the ecosystem. Other insects are reaching maturity, such as several types of native grasshoppers and katydids.
During the past two weeks, great numbers of mature lubber grasshoppers could be seen in many places in the valley floor. Their presence and abundance are a reflection of the monsoon rains that have enabled an explosion of plant life – a smorgasbord for grasshoppers. At this time of year, these bulky creatures have reached their final instar and are actively seeking mates.
A mature lubber grasshopper, Brachystolla magna. It is normal to see large numbers of these heavy, slow-moving insects during the tail end of our monsoon season. Note the tiny vestigial wings – this grasshopper is incapable of flight.
In mid-August, just after an afternoon rainstorm, I watched a female ornate box turtle emerge from the bosque to drink from a rivulet of rainwater. As she was slaking her thirst, I caught a flicker of movement some forty feet beyond her at the edge of the trees. It was a male box turtle. He had spotted her, and this was mating season. If you think turtles are slow, you have never seen an amorous male box turtle chasing a female! There is nothing subtle about box turtle sex. The males literally run down and attempt to corner the females, who move nearly as fast in their attempts to elude the charging males. Once the pair is joined, mating can take upwards of an hour.
A male ornate box turtle in hot pursuit of a prospective mate. I have seen this happen a number of times; what is most amazing to me are the distances at which the males first spot the females when the chase begins. In relatively level areas with open ground, males can visually discern females located at least 30-40 feet distant. Once a female is spotted, the male immediately makes a beeline to her at top speed.
The chase ends with a successful mating, allowing the circle of life to continue as it has for countless millennia.
Last week, my wife Kathleen discovered a new species of beetle, (one we had never seen here before), floating in a rain collection bucket. She rescued the hapless insect – a gorgeous, iridescent creature known as the Carolina tiger beetle.
This glittering, multi-colored tiger beetle got a new lease on life when it was rescued from a full water bucket.
Tiger beetles are incredible insects. The have been a part of my life since boyhood, when I often attempted to catch them as they raced across the ground with what seemed like otherworldly speed. Very few insects are faster on land than tiger beetles. Tiger beetles are hyper-alert predators equipped with unusually long hind legs for rapid propulsion. Their big heads house a pair of huge compound eyes capable of acute long-distance vision. The visual field of a tiger beetle encompasses more than a full hemisphere. When a prey item is spotted, tiger beetles run it down, then secure their meal with a set of long, formidable, serrated mandibles.
A lateral view of the Carolina tiger beetle, Megacephala carolina.
Most species of tiger beetles are diurnal, but the Carolina tiger beetle is an exception, preferring to be active after dark. I wonder if any part of these insects would glow under a UV light source? A number of other local nocturnal creatures glow under ultraviolet light, including scorpions and pocket gophers.
Butterflies are often abundant during the monsoon. As I was working outdoors one day, I noticed a fresh chrysalis hanging from some old wire fencing. I recognized its form; it had been made by a caterpillar that was a member of the butterfly subfamily Danainae. Insect species native to Arizona that belong to this group comprise three look-alike species: monarch, queen, and soldier butterflies.
The chrysalis hatched in a short time – only a week or so – to reveal a gorgeous queen butterfly. After hatching, the butterfly clings to the shell of its empty chrysalis, pumping blood into its unfolding wings.
Once the butterfly’s wings have expanded to full size, it is normal to see the insect remain perched for some time as it slowly opens and closes its wings, readying itself for its maiden flight.
Many plants native to the desert southwest have specially adapted themselves in a variety of ways to the summer monsoon season. One of the weirdest, most bizarre, and fascinating is a plant known as dodder. The first time that I encountered dodder, I stared in sheer wonder for some time while thinking “what the hell is that?”
Patches of dodder are a common sight during the latter half of the monsoon season.
Dodder grows as a vine, commonly forming a scattered profusion of very fine, yellowish tendrils that snake their way through the vegetation. It is a plant that cannot manufacture chlorophyll. Dodder survives by obtaining water and nutrients from other plants – it is an obligate parasite.
A closer look at dodder, (genus Cuscuta).
The weirdness begins just after a dodder seed sprouts following a monsoon rain storm. The minuscule seed – nearly microscopic – sends a small, shallow root into the soil while raising a tiny, thin tendril above ground. As the tendril grows, it starts to turn in upwardly-ascending spirals. It is not seeking light as most plants do – it is searchingfor a host. As the tendril lengthens, its spirals correspondingly enlarge, until it makes contact with a nearby plant. The tip of the tendril is chemosensory; it can literally sniff out what sort of plant it touches. Dodder is selective about the company it keeps – only certain plants will do as suitable hosts. If the tendril likes what it senses, it wraps itself tightly around the plant’s stem, then sinks a feeding tube – known as a haustoria – into the stem.
At this point, the seedling’s tiny root dies. The dodder plant then obtains all of its water and nutrients from its host. It will continue to grow and search, attaching itself to more plants. Once it has inserted enough feeding tubes into its victim(s), dodder reaches a point in its physiology that enables it to reproduce. Clusters of tiny white flowers erupt from the vine’s stem, ensuring the plant’s future.
Our local species of dodder sprouts clusters of small, white flowers – these grew from a dodder vine that had entwined itself on the stem of a pigweed (Amaranthus palmeri) plant.
So what is truly bizarre about this parasitic plant? Research has documented the fact that dodder actually steals sequences of DNAfrom its host plants’ genes, then incorporates them into its own DNA. The process is called “horizontal gene transfer.” This results in better survival for the dodder plants. It also enables them to manufacture strings of RNA that it sends back into the host plant, causing the host to weaken its defenses.
Dodder plants are classified as members of the Convolvulaceae – the morning glory family – with over 200 species worldwide. The genus, (Cuscuta), has a global range, occurring in tropical, subtropical, and temperate habitats. Dodder has a slew of common names, many of them derogatory – strangleweed, witch’s hair, devil’s guts, scaldweed, devil’s hair, and hellbine.
When considering this plant, we should strive to avoid the common propensity of our species to pass judgement on other life forms….often the result of our high capacity for arrogance-as-a-species combined with ecological ignorance. Simply because dodder is a parasite does not make it bad. Estimates place the percentage of parasitic organisms on Earth at 40-50% of all species. Clearly, parasitism is an essential part of the recipe for life on Earth. Here in the Middle San Pedro Valley, one of dodder’s favorite host plants is pigweed. Even when heavily infested with dodder, local pigweed plants continue to grow and produce viable seed.
I have seen more rattlesnakes around our home this summer than ever before. During the past six weeks, not a single day has passed when I have not seen at least one western diamondback here – on several days, I have seen as many as four. I don’t mind their presence. This would be a very dull world if it were danger – free, cleansed of any creatures that might harm us. The snakes have a right to be here – this land is not just habitat for me and my family, but habitat that we share with many other living things.
Yesterday morning brought a surprise that lay snoozing a few feet from my doorway. It was yet another rattlesnake, but the instant I saw this one, I knew it was not a western diamondback, but a Mojave rattlesnake.
Most of the time, when I spot a poisonous serpent close to our home, I simply leave it alone. Given this snake’s proximity to an area that gets frequent daily foot travel, and the extreme toxicity of its venom, I decided to relocate it. I picked the rattlesnake up with a pair of snake tongs, lowered it into an empty trash can, and hauled it to a new home downriver. During the entire procedure, the snake shook its tail only once, and briefly at that.
I knew immediately when I saw this snake under the ramada that it was a Mojave. The greenish-yellowish tinge to its skin stands out in contrast to the local western diamondbacks, whose coloration tends to be more silvery gray. Note also the sawtoothed edging to the snake’s dorsal blotches. Our diamondbacks rarely show such edges on their “diamonds,” or dorsal blotches.
How toxic is this snake’s venom? Some sources say the venom of Mojave rattlesnakes is ten times more potent than that of other rattlesnakes. (There is one notable exception here – tiger rattlesnakes, which also occur in the Middle San Pedro Valley, are nearly as potent as Mojaves.) Other sources label this species as one of the most toxic snakes in the entire hemisphere. That is saying a lot, especially considering some of the elapid snakes that live in Central and South America. As if that were not enough, research has demonstrated that the Mojave rattlesnakes that inhabit Cochise County produce a unique venom that is even more potent than that of other Mojave rattlesnakes in other parts of their range. Rattlesnake venoms are complex organic cocktails consisting of many ingredients including proteins, polypeptides, metal ions, fats, enzymes, and more. Most rattlesnake species have hemotoxic venoms – venoms that destroy red blood cells, interfere with clotting, and damage tissue. The principal components of Mojave venom are neurotoxic – they act on the central nervous system. A bite from one of these snakes can cause severe paralysis and even cardiac arrest.
So yes, I decided to move the snake away from our home.
This Mojave rattlesnake was captured and relocated by a warm-hearted friend a few years ago; he brought the snake to here to show it to me before releasing it back into the wild. This snake was on his doorstep as well, better relocated than shot or clubbed to death.
Much like sharks or grizzly bears, rattlesnakes are widely misunderstood and unjustly feared by the public. These fears are rooted in ignorance and a cultural bias regarding the world of nature and our place in it. Here in Arizona, where rattlesnakes are common and widespread, more than half of all bites are provoked. (Yes, Darwin was right!) Most of the remaining bites could be easily avoided by a combination of unflagging awareness, protective footwear, and snake gaiters. Awareness means keeping one’s eyes fixed carefully on the ground when moving around outdoors, and always using flashlights after dark. If you look carefully where you are going, you are much less likely to step too close to a snake. When I hike locally during the warm months, I always wear a pair of leather boots and snake gaiters. Simple precautions can really pay off.
Identification of Mojave rattlesnakes is not always a simple task; occasionally, these snakes hybridize with western diamondbacks. They also come in many differing shades of color. The most certain identifying characteristic are the two large scales atop the snake’s head that lie in-between its supraocular scales – (the very large scales that cover
the upper portion of the snake’s eyes). Western diamondbacks usually have six or seven much smaller scales between their supraoculars.
If a person does get bitten, it is imperative to get medical help as soon as possible. Time is utterly crucial when it comes to treating snakebite victims. In this rural landscape, that means a helicopter flight to a hospital in Tucson. The average cost of treating a bite victim has risen to over $75,000 per incident. With that in mind, I think that a small investment in a pair of snake gaiters (most cost less than $100 per pair) and some good boots is a very wise move.
Tail markings are also useful in identification. Mojave rattlesnakes usually show narrower, less distinct black banding on their tails than diamondback rattlesnakes.In contrast, most western diamondbacks have considerably wider, distinct black bands on their tails.
In closing this post, I must say that I do not recommend relocating reptiles. For rattlesnakes, relocation beats getting killed, but is stressful to them, and can result in an inability to survive. Rattlesnakes occupy definitive home ranges, areas that they come to know and navigate through successfully. One of the most critical aspects of their lives has to do with knowing where a suitable site is for hibernation. (The correct term in use these days is “brumation,” not “hibernation.” I used the old term because many more people are familiar with it.) If a snake cannot find its way to such a site, it is not likely to survive the winter. Relocated snakes have been documented to have problems with this, especially if they are moved late in autumn.
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?
July brought us over six inches of very welcome rain! The summer monsoon – one of five distinct seasons here – has returned to southern Arizona after a two-year near-absence. Purple martins are cruising above the treetops and a family of Mississippi kites has been visiting us for days. We are seeing rattlesnakes on a daily basis. On sultry, warm nights, elf owls have been calling in the wee hours of the morning. Saguaros are fattening as they transport water in their tissues. Native grasses are sprouting. The land and its life are rejoicing.
The changes on the landscape are incredible, happening with amazing rapidity and soaring fecundity. The mesquite bosque surrounding our home had been without a green understory during the entire past two years. Not any more! One glance out the window reveals a near-jungle of dense greenery standing five feet tall – much of it composed of one dominant plant with the unflattering common name of “pigweed.”
Fresh growth emerges with stunning speed and vigor after nitrogen-rich summer rains soak the land. This image is a week old; the understory plant community has doubled in height since then.
Pigweed is known to botanists as Amaranthus palmeri, and it is certainly not a “weed.” In the conventional sense, most of us consider weeds to be troublesome non-native plants. This one is a native species, and its presence speaks of great benefits to the land and its wildlife.
One of the primary winter forage plants for the deer that inhabit this river valley is pigweed. A good source of winter forage is critically important to wild ungulates. Rabbits, hares, javelina, and many rodents feed on the green plants in summer. Once the seed heads form, they tend to remain through autumn and winter on dead, standing plants. Great numbers of various species of sparrows winter in southern Arizona. The seeds of pigweed are heavily fed upon by many of these sparrows and other native birds as well. Something that is very obvious, but often overlooked by many people, is the fact that the dense stands of pigweed are shading the ground. I can’t stress enough how important shade is in desert ecosystems! The ground retains much more moisture and soil temperatures are far lower, allowing fungal hyphae and numerous other microflora and microfauna to work in shallower horizons of the soil. This benefits all life.
The summer rains bring many creatures out of hiding. Among these are toads, countless insects, red velvet mites, and the largest millipedes living in the United States…
Giant millipedes spend nearly all of their lives underground, typically emerging only after monsoon rainstorms. This one was about five inches in length; some sources claim this species can reach up to nine inches in length. These fascinating, innocuous arthropods can live for ten years, growing longer as they add more body segments every time they shed.I had taken several shots of the millipede, working close to the ground, before I noticed this small diamondback curled sixteen inches away. It never made a sound. When left undisturbed, these snakes are rarely aggressive. Their primary method of defense is stillness and excellent camouflage.When one of these huge beetles comes flying by, it is guaranteed to get your attention. This is a palo verde root borer, measuring in at three inches in length. These beetles are another example of the many species that are brought out from hiding by the rains.
For many of our of native amphibians, monsoon rains furnish their only chance to reproduce successfully. A strong population of spadefoot toads inhabits this valley, but they remain completely sequestered until strong summer rainstorms bring them up from their deep underground burrows. On July 3rd, the first monsoon storms rolled in – a succession of two storms with plenty of lightning and life-giving rainfall. That night, the landscape was ringing with the voices of hundreds upon hundreds of spadefoot toads.
Couch’s spadefoot toad is the most abundant amphibian in the Middle San Pedro Valley, but only summer residents witness them.A pair of Couch’s spadefoots mating. These amphibians must lay their eggs in water. In desert environments, the toads wait for summer storms to create suitable pools of water. Here, the male is grasping the female in a posture known as amplexus – when she lays her masses of eggs, he releases sperm into the water.
Spadefoot tadpoles mature more quickly than almost any other tadpoles on the planet – in as little as nine days. This is a species that has evolved to live in a hot, dry desert environment, where pools of water are not only rare, but tend to be very short-lived. It pays to mature quickly under such demanding conditions.It is hard to say what to call the amphibians in this brief period of their lives; tadpoles or toadlets? At this stage in their development, the tails shorten very quickly. As newly formed toads appear, they can be seen hopping by the dozens out of their natal pond. Just two days ago, despite the fact that I am always on the lookout for rattlesnakes, I nearly stepped on this one that was well camouflaged under the ramada. I am glad that we did not have an unfortunate interaction.
Mid-to-late summer is the most exciting time of year to be in southeastern Arizona; it is, by far, my favorite of the five seasons here. Locals know this time as the monsoon season, or simply, “the monsoon.” In a normal year, the majority of annual precipitation occurs during this time. Unfortunately, there were virtually no monsoon rains here in the Middle San Pedro Valley during the past two summers, resulting in a barren and desperately dry landscape. Thankfully, this summer has brought the gift of rain back to the land, with 3.38 inches falling at our location since early July, with more in the forecast. The result has been an explosion of life, much of which cannot be witnessed at any other time of year.
The tiny desert cottontail pictured at the top of this post is one of summer’s products. (A reminder to my readers: If you don’t see that image, it is because you are reading this in your email. Please click on the blog title to be redirected to my blog site (https://ralphwaldt.com), where you will see the featured image at the top of each post, and more that is not included in the email version).
Rabbits, (as opposed to hares – e.g., snowshoe hares or misnamed “jackrabbits”) raise their young in burrows and feed them milk for 3-4 weeks. After that time, the young rabbits are weaned and can leave the family group. This one was out exploring the world on its own for the first time. It was tiny enough to have fit comfortably in my cupped hand, and surely held a patent for cuteness.
Thousands of harvester ants begin to rise into the air the morning after the desert’s first major summer rainfall.
The first substantial rain of the monsoon season catalyzes desert life. Harvester ants (and other types of ants) wait for that particular rain to enable the most important annual event in their lives. In early summer, the ants produce legions of special individuals deep underground, individuals equipped with wings. Their purpose is to reproduce and disperse across the landscape. The day after the first rains, tremendous numbers of winged male and female ants flood from their nests to mate, rise by the thousands into the air, and fly away. This is a true spectacle to behold, an event that typically can be seen on only one day of each year. Freshly inseminated females (queen ants) quickly dig out a new nest and begin to lay eggs, thus founding new colonies.
So why the big deal about ants? If I were asked to name some of the most critically important players in this ecosystem, ants would be at or very near the top of the list. They are extremely numerous – they mix tons upon tons of soil – they disperse large quantities of seeds – and they aerate the soil, allowing for better gas exchange from atmosphere to soil, along with enhanced rain percolation into the soil. These points do not tell the full story of how ants are crucial to ecosystems, but they do serve to shed light on their exceptional ecological importance.
A living curtain of ants gains altitude, rising into the sky to begin journeys that will result in widespread dispersal across the land. Sights like this typically occur only on one single morning each year following the first monsoon rainfall.
Among the many effects of the summer rains is the repetitive flooding of the San Pedro River. The river grows rapidly after every major rainfall, sending torrents of flood water downstream. These floods are of great benefit to the riparian forests that line portions of the river’s banks, for they enable the cottonwood and willow trees to continue thriving as they recharge vitally important aquifers. These aquifers nurture the riparian forests and supply water for domestic and agricultural wells.
A rural road crossing on the San Pedro becomes impassable after rainstorms swell the stream. During most of the year at this location, the river is a mere six inches deep and less than ten feet across. When I took this photograph, the San Pedro had already receded quite a bit after a good run that had swelled the river to a width of over 150 feet and a depth of roughly 12 feet.
July brings the ripening of mesquite pods (or “beans”). This year, a good crop has literally covered the floor of the bosque. These pods – high in sugars, proteins, and fats – are a pivotally important food source for an incredibly long list of native creatures. Few, if any, native plants are more important or more beneficial than mesquite to this valley floor ecosystem.
A windfall of food for everything from mice to bears colors the floor of the bosque (Spanish for “woodland” or “forest.”)
These velvet mesquite seed pods are one of the most abundant and sought-after foods for local wildlife. They were also a staple food item in the diets of indigenous peoples.
In response to the photoperiod and summer’s warmth, rains, and raised humidity, many species of fungi reveal fruiting bodies. Among the most spectacular are growths of polypore mushrooms that emerge from the trunks of certain trees…
The fruiting body of this fungus sprouted from a mulberry trunk suddenly; within a matter of a few days it measured over 16 inches across.
A closer look – I believe this is Laetiporus sulphureus, commonly known as “chicken of the woods.”
Due to a near absence of monsoon rainfall, the floor of our mesquite bosque has been barren of understory plants for the past two years. The great gift of this month’s rains have brought the color of life back to the land, vivid green that feeds my soul while providing food and cover for many living things from microbes to vertebrates. With just a few more rain storms, this mantle of new growth is capable of rising quickly to heights of six feet or more.
Rain awakens countless seeds long buried in the duff, coloring this desert world with chlorophyll, a synthesis of the merging of soil, sunlight, and water into life.
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.
