I am happy to report that the Middle San Pedro Valley has finally received some summer rain! This has been a very dry summer – during July and August, we have received only .63 inches of rain. Most of that has occurred during the past four days. The summer “monsoon” season is what literally defines this ecosystem – enabling much of the rich assemblage of plant and animal species that makes this part of Arizona such a remarkable place.
Despite the extended drought, the velvet mesquite trees in the local bosque have put on a tremendous spurt of foliar growth this year. Additionally, the trees have flowered three times since spring. As I write this, the ground under the trees is plastered with a heavy crop of “beans,” the nutrition-packed seed pods that are one of the cornerstone food sources for our wildlife. How can this happen during such a bone-dry, hot spring and summer? The answer is rooted in last year’s very wet monsoon season. Mesquites have a remarkable ability to move rainwater down their roots, where they store it at depth for later use. That’s right; these trees can move water in both directions in their root systems! The big bean crop owes its genesis to last year’s stored rain water.
Wind plays a pivotal role in the ecology of velvet mesquite trees. When the seed pods are ripe, winds accompanying rain storms can release astounding quantities of pods in very short periods of time. Pods on the ground then become available to all wildlife, not just the species that climb trees. Mesquites depend upon animals to remove the tough outer seed coating by chewing and gnawing on the pods. The seeds of mesquite trees are able to germinate only after the outer husk is removed. This beautiful bumblebee appeared last week, an uncommon insect in local bosques. The ecology of bumblebees is intimately woven around the activities of small rodents. Local bumblebees make their colonial nests in the abandoned underground nests of mice and kangaroo rats.
Iridescent scales glitter on the back of this Clark’s spiny lizard, at rest in the shade of my ramada on a 108°F. day. Prime habitat for this species are mesquite bosques, where the trees offer an abundance of shade and escape routes from predators. Clark’s spiny lizards can climb trees with the speed and agility of an over-caffeinated squirrel.
Within the sheltered confines of a small depression in the joined trunks of two mesquites is a small rodent’s dining room – in this case, likely an Ord’s kangaroo rat. Note the many chewed fragments of mesquite pods. Kangaroo rats and many species of mice prefer such places to gnaw on their foods.
As of this writing, the raven family is still together as the trio of young birds explore their new world, constantly learning from their devoted parents. That’s papa Mike in the foreground, Mavis in the background, and their rowdy, inquisitive kids in between.
Mavis eyes up one of her favorite foods. Large eggs like this one must be held in the bird’s beak with skill and finesse. She sauntered off with this one, walking some 90 feet into the bsoque, then gently dropped the egg, dug a hole, placed the egg into the hole, then covered it with soil and duff. The spatial cognition and spatial memory of ravens is astounding. Hundreds of food items get stashed in tree crotches or buried for later use – with uncanny ability, the ravens remember where every one of them is hidden. This morning brought us a seldom-seen spectacular visitor in the form of this Gila monster that was crawling along the foundation of our home.
When viewed dorsally, the reticulated patterns on the backs of Gila monsters really stand out – patterns that are mirrored in the art of many native southwestern cultures and tribes. No two Gila monsters are patterned alike, so photographs can identify specific individuals. This one is an adult, about 14 1/2 inches in length.
May is such a beautiful month in the Middle San Pedro Valley! Our mesquite bosque bursts into new life, sprouting a light-filtering canopy of spring-green leaves. Birds are singing from the trees, building nests, and rearing their young. Lizards are a near-constant sight and snakes have been leaving their telltale trackways in the dust. Late in the month, something special happens as catclaw acacias suddenly explode with constellations of pale yellow blossoms, perfuming the valley with their luscious, signature scent. The heat of summer begins to blanket the land in newfound warmth, gearing up toward the frying-pan month of June.
This has been a banner year for catclaw acacia, Acacia gregii. The bushes (at times, these plants grow into small trees) have literally colored parts of the valley floor with an unusually dense show of blossoms. This is one of the desert’s special plants that begs to be appreciated in an olfactory way…push your nose up against any fresh flower, and one whiff of its sweet, heady perfume will weld the current zeitgeist of this wonderful region into your permanent memory. A dense stand of palo verde (Cercidium spp.) in full bloom colors an entire ridge with literally millions of flowers, all set beneath tall saguaros that are also in bloom. Palo verde and saguaro are two flagship plants of the Sonoran Desert Ecoregion, here reaching its southernmost boundary in the valley along this very ridge. The spot that I stood on to gather this image marks the northernmost extension of the Chihuahuan Desert Ecoregion. Two great ecoregions merge here, enhancing the rich biotic diversity that is so much an intrinsic part of the San Pedro River Drainage.
Most of the early wildflowers are gone by this month, but some wait for their bloom times, like this display of cow pen daisies, Verbesina encelioides.
A closer look at the vivid yellow flowers of cow pen daisies. The yellow “petals” are actually sepals – subtending the many dozens of tiny individual flowers that crowd the centers of these composite blooms.
I am happy to report that our resident Chihuahuan ravens have successfully fledged a trio of youngsters this year. This comes in welcome contrast to last year’s double brood failure; their initial brood was decimated by hungry coyotes on the first night that they spent out of the nest, and the second brood (rare in ravens) was lost to raptors.
Mavis skillfully positions a bulky chicken egg in her beak and readies herself for takeoff. The youngsters must be fed very frequently. Ravens are experts at finding the eggs of other birds. Mike and Mavis never hesitate when we leave an egg on the ground for them.
Loud cries emanating from the raven nest less than 120 feet from my desk window have been a daily part of this month’s panoply of happenings in the natural world. Young ravens have zero shyness when it comes to screaming at their parents for more food, more food, more food! Five days ago, they left the nest to begin exploring the outside world. We see and hear them many times a day as they roam with their parents and learn the complex magic of raven flight mastery. Few North American birds attain a higher level of flight skills than ravens do.
The three youngsters at rest in the mesquite trees only days after fledging. This is a vulnerable and crucial time for the young wolf birds. They must sharpen their flight skills quickly, for predators lurk above and below. It is also the one time in their lives when learning is greatly accelerated as they stay with their parents for weeks, who guard and teach their brood with steadfast devotion.
Raucous cries and characteristic fluttering wings are a part of every feeding, as Mavis approaches one of her ever-hungry youngsters with a crop full of food.
This has been a sad year for migrant birds, with fewer numbers and fewer species than usual, but there are still plenty of feathered creatures bringing life and – at times – utterly dazzling colors to our world. This male broad-billed hummingbird could not possibly have been dubbed with a duller nor less imaginative name.Among the resident bird species that are still doing well are lesser goldfinches, which crowd our seed bags daily, enriching our surroundings with cheerful choruses of bird song.
During every summer, wet mud or other moist places on the ground attract large congregations of gorgeous, diminutive butterflies.
“Blues” as they are collectively called, belong the the lepidopteran subfamily Polyommatinae. Approximately twenty species occur in Arizona. The moniker “blue” comes to light any time these insects open their wings, revealing brilliant blue coloring on their upper wing surfaces. The species pictured is known as the marine blue, Leptotes marina.
Only male “blues” congregate at puddles or on moist soil and animal scats. The males may require certain minerals, amino acids, and/or salts that the females do not. Local native host plants (for their larvae) include saltbush, catclaw acacia and velvet mesquite. Each species has its own hibernation strategy, with some overwintering as either eggs or larvae, as opposed to the far more common lepidopteran chrysalis. Other species have close associations with ant colonies – such as larvae pupating inside ant colonies, or larvae being tended and protected by ants as they feed on their host plants.
Warm morning light dapples the coat of this mature mule deer doe as she slakes her thirst at our “bird pond.”
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.
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.
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.
First, an important message to my readers: For a much better experience, when you receive notice of new blog posts in your email, please be sure to click on the blog’s title. That will take you to my blog website, where the photographs are larger and the text is more readable. Also, there is a “featured image” at the top of every new blog post that does not appear in the email version. Do this now – you will notice a substantial improvement!
Summer has come to the river and its valleys, bringing a cavalcade of change to the animal world. Today, my thermometer registered 113° F. I don’t leave southern Arizona during the summer like so many people do every year. This is my favorite season here, because so much happens in the natural world during the fierce heat of summer…
Mike and Mavis have successfully raised their seventh brood here on our land. This year, four new ravens have fledged and left the nest. Here are two of them. Note the pinkish-white bordering around their beaks and their pink mouths. As they mature, the pinkish color on their beaks disappears, and the inside of their mouths turns black.Several weeks ago, the velvet mesquite trees erupted with fresh blossoms. These are the precursors to an abundance of bean pods that provide one of the most crucially important food sources for the valley’s wildlife.A closer look at the flowers of a velvet mesquite tree. These blossoms perfume the air with a sweet, heady fragrance.A queen butterfly alights to drink from the wet mud surrounding our watering hole. This insect is often mistaken for its well-known cousin, the monarch.The back side of a male Gould’s turkey in full display. These birds – and their tails – are huge! The white tips on the tail feathers are one of the field marks that distinguish this race of wild turkeys from their eastern relatives. Part of the display involves dragging the wing tips on the ground, an action that creates a loud rasping sound, meant to intimidate rival males.A male summer tanager comes to feed from a block of suet. This is America’s only all-red bird, a living statement of resplendent color and grace. Their future in this valley is being threatened by large numbers of brown-headed cowbirds.This male black-headed grosbeak has been sending his voice through the bosque every morning, a series of loud, robin-like notes.Few of our western birds are more strikingly colored than the western tanager. A different race of this species stays here in the valley floor to breed every summer. Most western tanagers utilize very different breeding habitats – namely, conifer forests at higher elevations.A male blue grosbeak that visits daily for water. Blue is one of the rarest of colors among Earth’s terrestrial vertebrate animals.A new beaver dam graces the flow of the San Pedro River. Dams like this permit substantially more water to infiltrate the ground below their surfaces, recharging the shallow aquifers that give life to the river’s riparian forests of cottonwoods and willow trees. There were five more dams below this one. I cannot think of a single mammalian species that is more beneficial to the river and its forests than beavers are.I awoke one morning to find this characteristic fresh imprint at the foot of my entry steps. A rattlesnake had curled up there the night prior, leaving its signature circular mark. No other Arizona snakes rest in such a circular position. For reference, the grizzly track cast in concrete is six inches in width. Grizzlies were once common along this river until they were wiped out by Spanish and American settlers.A black-tailed jackrabbit resting in the shade of a mesquite trunk on a toasty summer day. When the heat cranks up, animal behavior changes. This hare let me approach within four feet, something it would not have allowed on a cooler day. The name “jackrabbit” is a misnomer, as these creatures are hares, not rabbits. Until I came to live in southeastern Arizona, I would not have believed that there could be pink snakes native to our country. This coachwhip snake appeared on a hot afternoon, five feet of blazing bubblegum pinkness! Coachwhip snakes are expert climbers. Kathleen and I looked out a window one day to see this tail protruding from an active Gila woodpecker nest. Fortunately, the snake did not wipe out the entire brood – it consumed one or two nestlings and moved on. A gopher snake encountered on a sandy bank of the San Pedro River. These snakes attain lengths of seven feet or more and are often mistaken for rattlesnakes. They are among the most effective rodent controllers we have. Favored food items include mice, rats, and gophers.A diamondback rattlesnake slithers through the mesquite bosque, traveling in a manner common among rattlesnakes, using caterpillar motion. When snakes crawl in this fashion, their bodies remain almost straight rather than sinuously curved. We never kill these animals. They have a right to live here, no less than we do. When summer comes, we are always on guard, watching closely where we place every footstep, especially after dark.Beavers add a special touch of beauty to the river, creating ponds that mirror their surroundings and provide needed habitat for a long list of other creatures.
This was one of those things that had to be seen to be believed. Recently, a friend sent me an email with some attached photographs of Chihuahuan ravens that he had taken in early May here in the valley. He kindly gave me permission to post his images on this blog.
There are some things that go beyond the “once-in-a-lifetime” category. Seeing a Chihuahuan raven with brown wings and tail surely must qualify.
In another instance, my friend was able to photograph a dispute between two ravens. The images appear to indicate a serious altercation. Such events are witnessed very rarely; even more rarely are they captured on a camera. I do not know what caused the aggression. It is nesting season for our local ravens. Perhaps one of the birds had tried to raid the nest of the other one, or was this a male vs. male squabble over a female? Only they know.
Two male ravens engaged in an uncommonly serious dispute. In all my years of watching ravens, I have never seen anything quite like this.Note the thick, heavy necks and heads on these adult Chihuahuan ravens. One way to tell the sexes apart is via such characteristics.
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.
