Among our most universal and compelling fears, one that is widespread across cultures, continents, and through vast spans of time, is the fear of snakes. In terms of simple survival, this makes perfect sense; many snakes can be lethal. For countless millennia, I am sure that people knew which snakes were dangerous and which were not.
In modern times, our culture has become so disassociated with the natural world that most of us can no longer identify what species are harmless and what kinds are not. The deep-rooted, possibly instinctual fear of snakes remains – when coupled with widespread ignorance, it results in the needless death of many snakes every year. You say rattlesnakes are easy to identify? Tell that to the many people who have killed slightly similar gophersnakes, thinking they were rattlers. Or to the screamers that wield shovels in attempts to automatically kill any snake they see.
The photograph above the title depicts a pair of mating western diamondbacks. A reminder – if you are viewing this in your email, you will not see the header images. Move your cursor over the title and click on it to be re-directed to my blog site, where the header images appear and where other images are larger as well.
What follows is a celebration of the beauty, grace, and elegance of the remarkable animals that we call snakes. Thirty-four species inhabit the Middle San Pedro Valley. Here is a sampling of a few that I have had the delight to encounter…
A Sonoran coralsnake, (Micruroides euryxanthus), a highly fossorial, nocturnal, (and therefore seldom-seen) species. The striking aposematic coloration of these beautiful reptiles is a clear warning to many would-be predators. Bites from these small snakes are very rare – and very serious. The venom is primarily neurotoxic; drop-for-drop, it outdoes any other southwestern snake for sheer potency.Sonoran coralsnakes are small, (rarely over two feet in length) shy, and retiring, preferring to hide their heads when threatened rather than strike defensively.
Gophersnakes, (Pituophis cantenifer), are Arizona’s longest serpent, capable of reaching lengths of over eight feet. These powerful constrictors are experts at preying on rodents. A special scale armors the front of their snout, enabling them to push through soil in rodent tunnels with ease. Gophersnakes play a key role in landscape-scale ecology by controlling rodent populations. This also makes them an ally to ranchers and farmers.
Sadly, many are killed by ignorant people who mistake them for rattlesnakes, and many more are intentionally killed by drivers, brutal acts that are a mark of cruel, simple-minded people.
While gophersnakes are common in Arizona, this one is very rare due to the aberrant patterning on the upper parts of its body. The usual dorsal blotches have been replaced by long, striped markings. Glossy snakes, (Arizona elegans), are quite common in the Middle San Pedro Valley. This species can attain lengths approaching six feet. At a glance, it is not hard to confuse these snakes with gophersnakes.
A Sonoran lyresnake, (Trimorphodon lambda), curled up against the wall of my adobe residence. Lyresnakes are fascinating; their large eyes feature vertically elliptical pupils, whereas most of our other snakes have round pupils. This is a nocturnally active species whose its diet is composed primarily of lizards. Lyresnakes don’t have injectable venom; instead, they secrete venom from glands in the rear of their mouths that is very toxic to lizards – but not to humans.
A typical “pink” coachwhip, (Masticophis flagellum). Coachwhips are often erroneously called “racers” or “red racers” by local residents. Coahwhips are phenomenal creatures, the true “über predators” of the southwest. Equipped with large eyes capable of exceptional long-distance acuity, coachwhips are the desert’s fastest snakes, and are surely among the fastest in the world. These are extremely alert reptiles that specialize on hunting lizards but will also consume a wide variety of other prey items. Coachwhips occur here in three color phases, with intergrades as well. The pink phase predominates locally.
I spotted this long-nosed snake, (Rhinocheilus lecontei), crawling across the dirt floor of our open shed on a warm, early summer morning. Its vivid colors and patterning are a reminder that snakes can be very beautiful creatures.
Long-nosed snakes occur in southern Arizona in two main color morphs. This is the other one, a completely different mix of colors and patterns compared to the individual above.
A California kingsnake, (Lampropeltis californiae). To me, this is one of the most beautiful snakes in Arizona, combining a chain-like pattern of cream-yellow bands set against a glossy, satin-black background. Kingsnakes are snake specialists, actively hunting many other species including rattlesnakes – kingsnakes are immune to their venoms. In addition to snakes, other foods include small rodents, eggs, and lizards.
A desert kingsnake, (Lampropeltis splendida) This species occurs locally in two primary color phases – the one pictured here is the most common. Some desert kingsnakes exhibit melanistic (all black pigmentation) coloration.Checkered gartersnakes, (Thamnophis marcianus) prefer habitats near water sources such as streams and ponds, where one of their favorite types of prey can be found most reliably – amphibians. Three species of garter snakes inhabit the San Pedro River Basin.
Rattlesnakes are the victims of more prejudice and brutal cruelty from people than all other American snakes – most often, the prejudice and cruelty arise from deep ignorance. We tend to overlook the comforting fact that rattlesnakes are among the very few toxic snakes on Earth that give us the courtesy of a warning. This western diamond-backed rattlesnake, (Crotalus atrox), is one of several that I see quite often around our buildings. Bites from this potent species are very serious, but also very rare IF one simply pays constant, close attention to where one’s feet and hands are placed when outdoors. We never kill these snakes, (nor any others, for that matter). Most diamondbacks are shy and inoffensive if left alone. Quite abundant in many habitat types, diamondbacks play a very important role in local ecology by helping to control rodent populations.
Of the world’s 36 species of known rattlesnakes, surely the black-tailed rattlesnake, (Crotalus molossus), would win one of the top prizes for sheer beauty. My wife and I spent half and hour watching and photographing this unagressive, beguiling individual. We found it basking, suspended several feet off the ground among tree branches in a walnut – velvet mesquite bosque. This one was large for its kind, close to 48 inches in length.
I had to radically adjust my search image for local rattlesnakes when I uncovered this snake in our shed, an Arizona black rattlesnake, (Crotalus cerberus), curled up beneath an inverted wheelbarrow. Before that moment, my search image had concerned itself only with the grays and dull browns of western diamondbacks; black rattlesnakes were not “known” to inhabit low-elevation places like our valley-floor bosque, situated at 3,100 feet. Since then, I have recorded this species locally several more times.
The Mohave rattlesnake, (Crotalus scutulatus), is the most potent rattlesnake in the entire American west, injecting substantial amounts of strong neurotoxic venom when it bites. This one emerged from under a stack of lumber that I had been working with, furnishing an unforgettable reminder that only fools slip their hands under wood stacked outdoors without looking carefully beforehand.
The most reliable way to visually identify Mohave rattlesnakes is to get a close look at their supraocular scales that lie atop the head between the snake’s eyes. It is difficult to do this safely without a good pair of binoculars with close-focusing ability. Diamondbacks can look quite similar to Mojave rattlesnakes, but their supraocular scales are much smaller and more numerous. Adding to identification difficulties, the two species have been known to hybridize in Cochise County.
Small and inoffensive, ring-necked snakes, (Diadophis punctatus) are common in the San Pedro River Drainage.
When threatened by a predator, ring-necked snakes may flip themselves upside-down, feigning death while revealing their striking, aposematically-colored ventral side.
Eastern patch-nosed snakes, (Salvadora grahamiae) feel like smooth satin when handled. This species is always among the earliest to emerge when the weather begins to warm in the valley, often above ground by mid-March. Note the heavy scale at the proximal end of the snake’s head, armoring for its snout as it digs underground in loose soils.
Upon lifting a pile of old branches and debris one day, I exposed this incredibly tiny snake, a highly fossorial species I had never seen before.
My first thought was, “I never knew earthworms lived on our bosque,” until I looked closer and picked it up. Coiled in my palm with room to spare was this amazing western threadsnake, (Rena humilis). Threadsnakes prey on ants, ant eggs, ant larvae, and termites. They are a favorite prey item for Sonoran coralsnakes.
Replace ignorance with knowledge. Be kind to snakes.
The snake pictured above is a black-tailed rattlesnake, Crotalus molossus. Of the nine species of rattlesnakes inhabiting Cochise County in southeastern Arizona, this one is my favorite. (If you don’t see the image, it is because you are reading this in your email. Click on the blog’s title to be redirected to my blog website for a better, more inclusive experience. Once there, simply scroll down the title page to quickly find this most recent post.)
If snakes could talk, when asked the question “what is hell?,” they would likely answer “any place where people are.” Many people kill snakes on sight, and others run them over with vehicles – often a brutal, intentional action. If snakes have dreams, surely one of their worst nightmares would involve becoming entangled in certain types of fencing, like chicken wire or plastic mesh. A snake can slip its head through the openings in these kinds of fencing easily. The trouble comes as the reptile moves forward. As the body thickens behind the neck, there comes a point when the snake becomes trapped. Scales on snakes overlap and point backward. The wire or plastic mesh gets caught under the scales, making it impossible for the snake to back out. A long, slow death is the inevitable outcome. I have seen live and dead snakes trapped in fencing more than a few times, especially in chicken wire and in various types of plastic mesh and bird netting. The bottom line is simple: if you care about snakes, don’t use these types of fencing! Find another way.
Late this summer, a neighbor called requesting my help to free this 4-foot Sonoran whipsnake, (Masticophis bilineatus). The snake was badly entangled in some plastic mesh fencing. It took quite some time with a pair of small scissors to free the snake. This feisty whipsnake tried to bite me repeatedly during the delicate procedure.
Sonoran whipsnakes are among the desert’s most beautiful reptiles. They are capable of incredibly fast movements much like their cousins, the coachwhips. Large, capable eyes give this creature excellent long-range vision for hunting its prey and avoiding predators. These snakes are semi-arboreal, often found high in the mesquite trees, where they move with skilled grace in search of lizards and bird nests. This one had skin that felt like fine silk, remarkably smooth to the touch.
October brought this 3-foot Sonoran gopher snake to our residence. I have never seen gopher snakes as richly colored as the individuals I have encountered in this river valley. They are Arizona’s longest ophidians, (reaching lengths exceeding eight feet) and they are always more than welcome here. Few predators are more adept at capturing mice, rats, and pocket gophers, for these animals can do what most other predators cannot – they can crawl down into the rodents’ burrows. Nowhere else have I seen box turtles as gorgeously marked as our local variety. This is an adult – some of these turtles lose their stripes, fading to a solid brown as they get older, but not this one. The species is Terapene ornata, otherwise known as the ornate box turtle.
Yet another Gila monster visited our property this year. This one was an adult measuring close to 14 inches in length. These lizards are readily identifiable as distinct individuals, for their complex markings are never the same, somewhat like our fingerprints.The track of an opossum may be a common sight east of the Mississippi, but here it is something special. Most of the opossums in this valley are representatives of a Sierra Madrean subspecies, reaching the northern tip of their range here in SE Arizona. This distinctive footprint, along with others, appeared in the fine dust under my ramada early one morning.
Southern Arizona is among the top places in the nation for frequency of lightning strikes. Summer monsoon storms can be fierce and utterly unforgettable, particularly when they occur after dark. On the first day of September, a bolt slammed to the ground some 55 feet from where I had been seated. The bolt followed this upright support post on an open shed as it made its way downward. The carbonized streak is clearly visible on the post. The electromagnetic pulse from this strike fried our home telephone system.
For the past twenty years or so, I have participated in a coordinated volunteer project aimed at monitoring the presence of water along the length of the San Pedro River in southeastern Arizona. Organized by The Nature Conservancy, this project provides important data to scientists, land managers, and many others on the health of the river system during the hottest and driest month of the year. The data is collected the old-fashioned way – gathered by teams who experience the river in the best and most intimate manner possible, by walking and wading. Every June, I collect a portion of this data along a rare, perennially-flowing reach of the San Pedro located in the river’s middle valley, often accompanied by friends and neighbors. This year, two wonderful friends who also happen to be great neighbors assisted me in this worthwhile and delightful task.
Since June always brings oven-like temperatures, we began walking around 5:30am along a waterless stretch of the riverbed. Almost immediately, we discovered fresh tracks of an adult black bear and a cougar, etched in dry sand. One and a half miles in, the magic of water appeared. From that point on, the river flowed steadily. Because the brush is often nearly impenetrable along portions of the riverbanks, we waded, a much easier way to travel as long as one can avoid hidden lenses of quicksand. More mammal signs and tracks appeared; Coue’s whitetail deer, mule deer, javelina, coyote, bobcat, raccoon, coati, skunks, cottontail rabbits, mice and rock squirrels. Familiar bird songs spilled from the forest; summer tanagers and kingbirds, ash-throated flycatchers and song sparrows, southwestern willow flycatchers and black phoebes, grey hawks, tyrannulets, northern cardinals, Lucy’s and yellow warblers, and more.
The river in June is a different world from the surrounding vastness of desert habitat types – humid, verdant with profuse life, cool and shaded. It feels and smells almost subtropical. So much life graces the river and its forests in June that these annual walks have become my favorite time to explore and experience the beauty of the San Pedro.
Wading this desert river in the heat of June is magical. The cottonwood-willow forest stands tall and green, casting shade and coolness enabled by millions of fluttering leaves. The forest’s understory is verdant with lush growth. Eight-foot tall burr reed (genus Scirpus) plants crowd the riverbanks. Aquatic patches of speedwell (genus Veronica) glitter with multitudes of blue-purple blossoms. Tall willows form a vivid green arch overhanging the river. Birds sing from the depths of the forest, many butterflies, bees, and wasps drink from water’s edge, and scores of lowland leopard frogs leap at one’s every step. Below the surface, schools of long-finned dace are darting like shafts of animated light through the clear water. The continued presence of native frogs and fish are strong, positive indicators of the health of this aquatic ecosystem.
Among the most remarkable predators in the insect world, dragonflies are a common sight along the summer river. Some twenty-two years ago, an entomologist discovered nearly one dozen species of dragonflies and damsel flies that were new to science along this part of the river.
We waded for a couple of miles, feeling the warm, shallow waters of the river filling our shoes, until the waterway started to broaden and slowly deepen. I suspected a beaver dam was ahead. We climbed up on shore, then began to weave our way through a dense tangle of tamarisk and seep willow. Before long, we could see the beaver pond clearly, the water deeper and deeper, then the dam, plugging the river with a meter-tall, thirty-foot span of branches, twigs, tree limbs, rocks, and mud. I was elated to see that this reach of the river had beaver activity once again. The ecological and hydrologic benefits of beavers to this river – and many other waterways – are legion. I devoted an essay to this important topic in my book, The Life of the San Pedro River.
A cool, deep pond extends upstream of the beaver dam. Such dams hold more water within the river system, helping to recharge the aquifers that feed the river and its forest. The positive benefits of beaver ponds to plant life and many wildlife species could fill a book. Note the turbidity of the impounded water, a sign that the beaver(s) had been active there the night prior.
A moment of reflection seated atop the beaver dam before I was almost envenomated by a rattlesnake. Photo by Tom Talbott.
My companions and I slithered down the steep riverbank to begin wading the final stretch below the dam. We had taken just a few steps when one of my friends suddenly threw his arm around me and pulled me out of harm’s way. A 3-foot western diamondback rattlesnake, coiled too close for comfort along the edge of the river channel, erupted in a frenzy of rattling. The forward third of the reptile’s body was off the ground and formed into an s-curve as the snake’s glistening black tongue waved slowly, curled backwards over its snout. Fully cocked, primed, and quite willing to strike. My fresh shoe print was about 14 inches from the rattlesnake. Had I not been yanked so suddenly by my alert friend, this snake would have probably tagged me. I have never come so close, despite encountering hundreds of diamondbacks here over the course of the last two decades. This experience underscores a crucial rule that I try to teach to everyone that I take into the wilds here – you should watch where every footstep is headed during the warmer months in southern Arizona! Sometimes, that is easier said than done.
This is the snake that I stepped far too close to, coiled, rattling, and very ready to strike defensively. Note the recent injury on its back, something that may have amplified its angry mood. If I weighed in at less than a pound or two, and a huge, towering, 200-pound bipedal mammal threatened to step on me, I’d be in a biting mood too.
I have always looked forward to the month of April in southeastern Arizona, for it brings a great diversity and large numbers of migrant birds to the land – or does it? The first time that I birded the San Pedro River was in April of 1977. In a word, that was a stunning experience. The numbers of birds were incredible, as were the variety of species. Today, the story could hardly be more different.
Migrant songbirds (and other migratory species) have been steadily declining ever since Europeans began to populate the North American continent. The rate of decline was slow at first, but it has increased continually through the centuries. During the past several decades, declines in bird populations have become so severe that some birds have become extinct, while others are persisting by the thinnest of threads.
Here in the Middle San Pedro Valley, I have been participating in avian surveys and have been keeping detailed records of local bird life for 21 years. The data is disheartening, but this year has been the worst thus far. Numerous species that have appeared on schedule at our property every past April are simply not appearing. Many others are here in very low numbers. Sadly, close to 100% of these declines are attributable to mankind. Overpopulation, urban expansion, climate change, pesticides and herbicides, tremendous habitat losses, loose house cats, and more add up to a world that is becoming quieter and quieter every spring.
What is spring without bird song?
Other happenings in the natural world have been occurring as well, ones that are not disheartening. Lizards and snakes have awakened from their winter brumation to add their grace, color, and life to the land. A few days ago, a Sonoran gopher snake appeared a few feet from my doorway, followed by the year’s first diamondback rattlesnake and the emergence of Clark’s spiny lizards. Our resident ravens, Mike and Mavis, have successfully hatched yet another brood and are very busy keeping their youngsters well fed. A nice abundance of wildflowers is coloring the upland slopes.
The gopher snake mentioned above. We always welcome these harmless and beautiful reptiles. They play an effective role in controlling rodent populations.
This was a slender male, close to 3 1/2 feet in length. Sonoran gopher snakes can attain lengths approaching eight feet, making them one of the nation’s longest native ophidians.A closer look reveals the large, curved, robust rostral scale at the forward tip of the snake’s head. This kind of scalation evolved to shield and protect the heads of gopher snakes as they push their way through soil and pursue rodents deep into their burrows.
Every year in this valley seems to bring its own explosion of certain insects. Earlier this month, incredible numbers of crane flies could be seen. I recall walks where every step flushed 20 or more from the surface of the ground. Crane flies belong to the family Tipulidae, with over 15,000 species worldwide. They are a successful and adaptable group of insects, for their presence in the fossil record dates back over 70,000,000 million years.
A pair of crane flies, busy assuring that their kind has a future. These innocuous insects are sometimes called “mosquito hawks,” for the mistaken belief that they prey on mosquitoes. On a recent walk in the valley with a friend, we paused to admire this rare cristate saguaro, made even rarer by its unusual paired, symmetrical shape.
Incredibly, on the very same day, another friend was roaming the valley when he discovered this huge, cristate specimen. Photo by Gilbert Urias. April brings the return of turkey vultures. Here, one has landed to scrutinize one of our bird watering dishes. Among several unique aspects of these vultures is the fact that they have no syrinx – the organ that allows birds to vocalize. Turkey vultures can hiss by expelling air rapidly, but they cannot call to one another nor utter any sort of song.A close look at the vulture’s head reveals a large perforation in the bird’s beak. When viewed at just the right angle, one can see that the large hole goes all the way through the beak to the other side. Turkey vultures locate the majority of their food via a keen sense of smell, an unusual trait among most other birds. The perforated beak likely helps these birds to smell with great facility, channeling airflow into their nasal scent receptors. (The quality of this enlarged image is poor due to limits that my blog hosting service places on image resolution.)
Shallow watering dishes can do wonders for attracting bird life and many other desert animals as well.
A wonderful and always reassuring sight! The riparian forest that is so deeply important to the valley’s wildlife glows with a verdant spring canopy of cottonwood and willow leaves. The color contrast between the riverside forest and the surrounding uplands is strong in April. The forest – a true hallmark of this valley – is completely dependent upon the San Pedro River and its subterranean aquifers.
Darkness settles over the land. Many miles from the lights and sounds of towns and cities, Arizona’s Middle San Pedro Valley sprawls wild and still. At twilight, only a faint poorwill and a pair of great horned owls can be heard. The coyote telegraph erupts and then fades as it travels from ridge to distant ridge. In contrast to the rich variety of summer sounds, an autumnal hush blankets the countryside.
At day’s end, dusk gently ebbs into darkness as a brilliant October moon emerges from the far shores of the eastern horizon. Here, in our mesquite bosque, the peace and comfort of the night suddenly give rise to a thousand voices raised in the jubilance of courtship. These are sweet, almost melodic sounds – October’s distinctive nocturnal biophony. Tree crickets are singing from the ancient trees, thousands of them spread across the valley floor, their songs a vivid proclamation of thriving life within an otherwise quiet forest.
This species of tree cricket sings from the tall mesquites in our bosque. Its ecology is intimately connected to velvet mesquite trees. These are small insects with a big voice.
I have come to love the sounds of these delicate, gossamer-winged insects. Long after summer’s insect frenzy, when most species have faded from the scene, tree crickets come to life in the coolness of October nights. The males raise their transparent wings, then call to the females by stridulating – in other words, they rub certain parts of their bodies together to produce a surprising volume of sound. Females are drawn to these love songs. The males go one step farther by offering their mates a special reward. After mating, metanotal glands located on the dorsal side of the male’s abdomen secrete a substance that the female feeds on.
Eight species of tree crickets inhabit southeastern Arizona, where they produce two generations each year. The ones singing in local October bosques belong to the genus Oecanthus. Each species has its own unique song. However, even among the same species, sound can vary quite a bit depending upon air temperature. The frequency (or pitch) of the crickets’ songs increases as temperatures rise and slows as temperatures fall.
A bizarre butterfly landed on my screen door last week – an American snout butterfly, Libytheana carinenta. Last year, large numbers of these butterflies erupted all over the valley in late summer. Snout butterflies use their strange shape to blend in with their surroundings. When perched on a plant stem, their elongated “snout” breaks up the outline of their bodies, resembling a broken twig or a thorn. The range of snout butterflies extends all the way to South America. They are known for migrating across landscapes in huge aggregations.
A study in camouflage, the American snout butterfly sports wings that blend well with tree bark and a unique body shape that helps to conceal the insect when at rest.
This summer’s plentiful monsoon rains have continued well into October. Since the monsoon began on June 18, our rain gauge has recorded an amazing 13.46 inches of life-giving rainfall.
One of the local washes experienced some large summer floods. I took a walk down this wash with a friend a few weeks ago, to have a look at the powerful changes wrought upon the land by the big floods. What we saw was in stark contrast to the wash I had known from walks during the past several years.
During recent times, this broad wash had been covered by a wall-to-wall effusion of burro bush (Hymenoclea) standing six or more feet tall with a galaxy of roots anchoring the bushes to the ground. The flood had erased most of that growth, leaving behind a clear streambed lined with heaps of debris – tree trunks, plant material, rocks, and more. The floor of the big wash had been totally rearranged, its topography and course markedly changed during a couple of events that lasted only days.
In places where floodwaters form swirling, circular eddies, holes are dug into the wash floor like this one. These depressions can be very large and quite deep. They often hold pools of surface water that can last for months after flooding, a valuable offering to birds, mammals, and other wild creatures in this desert ecosystem.
Powerful floods like these transport thousands of tons of boulders, rocks, gravel, sand, clay, and a wide variety of organic materials – whole trees, cacti, and other plants. Downstream, entire soil profiles are altered and built as sediments settle from the turbid waters. Cutbanks collapse, dropping great layers of soil into the roiling floodwaters, releasing seeds that have lain dormant from ancient times into the present-day ecosystem. Old genetics from times long gone may invigorate plant populations and enhance the genetic variability – and hence, the viability – of modern plant communities.
Most people would simply label this collapse of a stream-side cutbank as “erosion.” That is an accurate use of the word, but I see much more going on here.
Debris piles left along the stream banks can be very large, consisting primarily of tangled, broken bushes, parts of trees, and other plant matter. They provide shelter and denning sites for small mammals, reptiles, amphibians, and other creatures. Floods are not all bad – they are simply a natural, intrinsic agent of change, some of it beneficial, some not. People often label floods as “bad,” but that viewpoint roots in anthropocentric thinking, a myopic way to view our world.
The ecology of many native species of plants and animals actually depends upon flood events. The beautiful stands of cottonwoods that line the San Pedro River could not exist were it not for floods creating the specific conditions that their seeds require for germination. The riparian forests that accompany the river depend upon having their roots tap into subsurface aquifers. The aquifers get recharged when floods happen.
As floodwaters recede, the bed of the San Pedro River leaves records of local wildlife in the drying mud. Here, the patterning of fine surface cracks results from a place where the river water subsided very gradually with little or no turbulence, resulting in the deposition of extremely fine clay particles. As these clay deposits dry, they crack in characteristic patterns.
October typically brings us the last ophidian visitors of the year, most of them not to be seen until next spring. A beautiful gopher snake was here last week, and as I write this, a diamondback is curled up a short ways from my entry door.
An October gopher snake, crawling along the wall of one of our buildings. This one was a male, measuring right around 63 inches in length. Always welcome here, as are all snakes.The year’s last generation of pipevine swallowtail butterflies occurs in October. I found this gorgeous caterpillar recently – it is either in the fourth or fifth (last) instar of its development, after which it will climb a plant stem and metamorphose into a chrysalis suspended by a single loop of silk as it waits out the winter season. The leaves visible in this image are pipevine leaves, (Aristolochia), the only plant that these caterpillars feed upon.
October is THE month for seeing pinacate beetles (Eleodes spp.) – they are literally everywhere at this time of year, easily noticed because of their large size, slow movements, and diurnal habits. When they feel threatened, pinacate beetles stop moving and assume this head-stand posture. If the threat escalates, (for example, when a bird tries to grab the beetle), the beetles fire a noxious, very disagreeable fluid from the tip of their erected abdomen. Chemical defenses are very common among many insect species.
Just a few days ago, I noticed this small tuft of feathers laying on the ground. Immediately, I began searching the area for more, because such a find usually indicates that a bird was recently preyed upon somewhere nearby.
I soon found many feathers like this, their shafts intact. Intact shafts indicate feathers that were pulled out, not bitten and yanked out as mammals do. So this was the work of a predatory bird, likely a Cooper’s hawk that I have been seeing frequently of late. This was a special find, for these feathers could have come from only one species, a gilded flicker. Gilded flickers are relatively rare in local bosque habitats.
The lightning bolt slammed into the ground with thousands of times the force and speed of a sledgehammer blow on an anvil. It struck so close to me that I heard no thunder, only the unmistakably loud, monstrously powerful “snap” that is characteristic of a bolt that hits far too near to its observer. I had been sitting on my bed reading when it happened; I knew instantly what had occurred, for this was not the first time that lightning had struck so close to me that no thunder could be heard. Many years as a guide in the wilderness mountains of Montana had brought me into near-contact with lightning along high ridges at timber line more than a few times. It is one of nature’s most lethal forces when it strikes living creatures, but the other side of lightning is that it is one of the world’s most quintessentially important life-giving phenomena. For the full story, see pages 204-205 in my book, The Life of the San Pedro River. The next morning, I found the place where the bolt had impacted. A tape measure revealed that the lightning had struck 53 feet away. The electromagnetic pulse from that bolt fried our telephone system and our computer router.
The storms of this year’s monsoon season in southern Arizona have been wonderful – thus far, our rain gauge has registered 9.56 inches of rain since mid-June, resulting in a grand resurgence of life all across this hot and formerly dry landscape.
On the morning of August 20, a serious storm pounded the ground with so much rain that the area around our buildings became an unbroken sheet of water. I could hear toads starting to call from our overflowing bird pond. Before long, dozens of spadefoot toads came out of their underground lairs to join in the party, all of them hopping and swimming through the flooded landscape in beelines toward the pond. This was a critical time for the amphibians, for in a normal year, they get only one or two brief chances to breed. It was also a rare sight, for I have never seen such activity in the daytime…but this was a doozy of a storm.
Mavis – the female half of the raven pair that we share habitat with – takes shelter from the storm under the roof of our shed.
As the rain subsided, I stepped outside. I heard the familiar roar of one of our local washes that had become engorged with flood water. A short walk of a quarter mile took me to a place where I could look down from the edge of a vertical cutbank at the flowing wash…
The view from the cutbank after 2.6 inches of rain from a single storm swelled Hot Springs Wash with roiling floodwaters. Only a single channel is visible in this image. The waters braided across the broad wash floor in an ever-changing – and growing – number of channels. Powerful floods are characteristic of desert washes with large drainage areas (this wash drains an area of about 100 square miles) and steep slopes in their headwater areas.
Next, I walked over to see what was going on in the little pond – there were eight pairs of Couch’s spadefoot toads in amplexus! A couple days later, after thousands of toad eggs hatched, our pond was teeming with wriggling throngs of tiny tadpoles.
Couch’s spadefoot toads mating in our pond. Each female usually lays hundreds of tiny eggs during such couplings, as the male releases sperm into the water.After the mating frenzy, myriad spadefoot eggs clung to every blade of grass afloat in the water.
Later in the day, Kathleen and I walked down the road to have a look at where the big wash crosses the road. The sound of the flood grew loud as we approached a point where we could see the flow, over 300 feet in width. The dirt road – the only road that serves the entire valley – had become impassable once again. In the midst of the turbulent flow, where the waters ran deepest, trees were being tossed around like toys, ripped from their root-bound moorings as they sped downslope toward the San Pedro River. Hundreds of tons of sediment, gravel, and rocks were being transported toward the floor of the valley in a rip-roaring tumult of rain water.
A view of the flood as it obliterated the roadway where it crosses the usually dry bed of Hot Springs Wash. During the twenty summers that I have seen this wash respond to rainfall events, only twice have I witnessed it running larger than this.
As we were watching the floodwaters, I climbed to a higher vantage point, where I discovered this beautiful Sonoran gopher snake. The snake allowed me to gently approach within a foot or so. This was a fine specimen, over 5 1/2 feet in length.
A few hours later, the sun had melted down into the nether regions of the western horizon. My wife and I walked outside around 11:00pm to listen to the night sounds. After turning off our flashlights, we witnessed something that is seldom seen here – fireflies!! Few of Earth’s creatures are capable of instilling such an immediate and compelling sense of awe and wonder as fireflies are. They were emitting distinctive, paired flashes of remarkably bright green light – in so doing, they identified themselves down to the species level. We were seeing southwestern synchronous fireflies, Photinus knulli.
A couple of days after the big storm, I walked down to the San Pedro River. Many areas within the river’s drainage had received substantial rains, bringing the river to life. Here, el Río is surging along with a flow roughly 180 feet in breadth and over six feet in depth.
Downstream, a group of turkey vultures was roosting in a pair of dead cottonwood trees. Dead trees are an essential and important component of all forested areas on Earth. All too often, humans fail to recognize this aspect of our planet’s ecology. Our culture – embedded in the ecologically dangerous Abrahamic concept of land use – (the land is here to produce our milk and honey, for human use) – tends to see dead trees as “going to waste.” “Salvage logging” of our national forests after wildfires is an exemplification this anthropocentric view of our living world.
The rainy season brings twilight flights of thousands of buprestid beetles just above the canopy of our local mesquite bosques. Here, a very rare sight unfolds as a female Polycesta aruentis everts her ovipositor to lay her delicate eggs deep within the sheltering crack of a mesquite stump, where they will be out of reach of the sun’s touch. Her larvae will hatch to bore their way through the wood, leaving tunnels in their wake that greatly facilitate the entry of fungi and other agents of decomposition. Thus, insects like this play a critically important role in forest ecology.
A half-grown (about four inches in length) Sonoran desert toad enjoys our bird pond after a rain. These amphibians grow to prodigious sizes. If I am not mistaken, they are the heaviest toads native to North America.
Living in remote parts of the desert southwest demands some important learned behaviors. Only fools step outside without looking first. This diamondback had just finished crawling across my entry steps when I took this photo. Snakes of all kinds are always welcome on our property – but continuous caution when one ventures outdoors is an imperative part of living here.
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.
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.
