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.
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.
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.
Late in the evening of April 17th, new sounds could be heard emanating from the surrounding mesquite bosque. Barely audible but familiar from prior years, the sounds were raspy, tremulous, unique. They were the first thin cries of hatchling ravens, born to none other than our pair of resident Chihuahuan ravens, Mike and Mavis. This new brood marks their seventh successful nesting on our property and their first in the new nest (described in my previous blog post). As always, we are honored to share habitat with these regal birds. We look forward to watching them raise and teach their young. Few North American birds spend as much time rearing and educating their young as ravens do.
The demands of a raven’s day-to-day life reach a crescendo during nesting season. After the chicks have hatched, both parent birds spend their days defending the nest from predators and making countless trips back and forth to bring food and water to their young. Nestling birds require amazing amounts of food at frequent intervals. Here, the mother raven is about to abscond with a tasty block of suet.
The past year has been the driest I have ever witnessed in southeastern Arizona. Last year’s crucial summer rains barely happened here in the Middle San Pedro River Valley, and the following winter rains were extremely sparse. The landscape is desperately dry, even for a desert, so signs of spring have been more welcome than ever. One of them appeared several weeks ago when a black swallowtail flew in to get a drink from a muddy patch of soil near one of our bird water dishes. Butterflies play very important roles in the ecology of this ecosystem. They grace our lives with their flight and their remarkable beauty.
A black swallowtail, (Papilio polyxenes), gets a drink from a patch of wet soil. Caterpillars of this species can be found primarily on plants in the parsley family.
Another sign of the changing seasons was the emergence of a beetle known as the fiery searcher. Just over an inch in length, these beetles display gorgeous coloration; an indigo-purple head, thorax, and legs with emerald green, iridescent elytra (wing coverings). This marked the first time that I have ever encountered this species here in a mesquite woodland. Usually, I find them in the riparian cottonwood-willow forests along the San Pedro River.
A fiery searcher, (Calosoma scrutator ). This insect is classified within the family Carabidae, the ground beetles. Fiery searchers are active during the day, hunting caterpillars and grubs. The species pictured here manufactures noxious chemical compounds for defense; they smell horrendous and probably taste just as bad to potential predators.
Another certain sign of spring is the emergence of reptiles. A few weeks ago, I had a surprise when I retrieved a wheelbarrow from an open shed. I always keep wheelbarrows flipped over so that rain water cannot accumulate inside and rust them out. When I flipped the wheelbarrow over, here is what I found…
This western diamondback had discovered a safe, dark place to hide in, until I needed the wheelbarrow.
I have found rattlesnakes under my wheelbarrows more than once in the past. All snakes – including rattlesnakes – are always welcome on our land. We never kill them. Once in a rare while, I will capture and move one to a safer locale, but usually I simply let them be, like this one. I do my best to respect all life!
A closer look at the formerly hidden snake. Rattlesnakes at rest almost invariably assume this characteristic, circular posture. With respect to most species, snakes can be readily identified by their markings and coloration. Rattlesnakes, gopher snakes, and many other snakes can be recognized even further, as distinct individuals. The markings on their heads and necks are individually unique, much like our fingerprints.
Yesterday, another sign of spring showed up nearby, a beautiful glossy snake. They are among the most common snakes in local mesquite bosques. Glossy snakes can reach lengths approaching four feet and feed on mice, kangaroo rats, lizards, and other snakes.
Glossy snakes are commonly mistaken for gopher snakes. One of several ways to tell them apart is that gopher snakes have keeled scales on their backs, whereas all of the scales on glossy snakes are smooth. Their technical moniker is hard to forget: Arizona elegans. The whitish object in the upper left quadrant of the image is a velvet mesquite bean.
The local stands of mesquite furnish very high quality firewood in addition to providing crucially important habitat to numerous wildlife species. Recently, a dead mesquite was felled here on our place that was threatening to crush one of our buildings if it were allowed to fall naturally. I sawed it into firewood. Other dead trees are left standing, for they are very important to many living creatures and to the health of the soil that they will eventually become a part of.
We live in an age when most adults and even our children are soft, weak, and overweight. Machines now do much of our work for us, and recreation often consists of vegetating in front of a computer screen or playing sedentary video games. A little physical work will always do a body good. I have felled, bucked, hauled, and stacked more firewood than I can ever recall. My decades in Montana always included a demand for at least eight cords of wood annually. Even here in southern Arizona, winters get chilly and a warm wood stove can be a real comfort on frosty nights.
