Category: mesquite bosque

The EGGS Have HATCHED! Signs of Spring Adorn a Desperate Landscape

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.

Living Jewels that Seek Fire and Eat Wood

Among the most important components that power the machinery of forest life are insects – beetles in particular play crucial ecological roles in forests.  One of the largest beetle families is the Buprestidae, represented by nearly 16,000 species. These creatures are known as “jewel beetles” due to their family’s spectacular array of iridescent colors and patterns. The insect pictured above is one dazzling example, native to the coniferous forests of the Rocky Mountains.

One of the world’s largest jewel beetles is Euchroma gigantea, native to Amazonia. These insects can measure over two inches in length. This is a mounted specimen from Brazil, part of the author’s collection.

In most living organisms, iridescence is enabled by pigmentation. Jewel beetles are different – their iridescence is structural in origin; microscopic texturing on the surfaces of their exoskeletons selectively reflects specific frequencies of light while absorbing others.

Most jewel beetles lay their eggs on dead or dying trees. Once the eggs hatch, the beetle larvae go to work, chewing their way through the wood. They leave a maze of tunnels in their wake. Some species of jewel beetles will lay their eggs only on freshly burned trees. These specialized insects are known as pyrophiles (literally, “fire loving”). Forest fires create a nearly instant Shagri-la for them.

The larvae (or grub) of a jewel beetle found inside a section of velvet mesquite wood. These larvae are often known as flathead borers due to the shape of their heads. The tunnels that such larvae create in dead wood are of great importance to forest ecology.

Pyrophilous jewel beetles have evolved specialized extra-large wing muscles to enable long distance flights to wildfire sites. These beetles have a way of finding burned trees that borders on the miraculous…

One of the buprestid beetles native to velvet mesquite bosques in southeastern Arizona. Note the heavyset, thickened body of this insect, a specialized morphology that allows room for large, powerful flight musculature.

When they fly, these beetles hold their bodies at an angle, in order to orient their underside to the direction of travel.  Minuscule texturing on the ventral side of the insect’s thorax functions mechanically in response to incredibly faint traces of infrared radiation (heat). Infrared radiation causes a pressure differential to occur in the thorax texturing. This fires neurons, sending a message to the beetle’s brain. The message says “fly in this direction and you will find a smorgasbord of freshly killed trees to provide food for your offspring.” What is even more amazing is that these insects can detect the heat given off by fires at distances up to fifty miles!  (research conducted by Dr. H.P. Bustami and associates at the University of Bonn [in Germany] brought this astounding facet of jewel beetle biology to light.)

A living jewel adorned with iridescent gold flecks and shimmering purple-sapphire elytra, this native buprestid inhabits local mesquite bosque habitats.

This relationship between forests, fire, and beetles has been going on for countless millennia. However, people often take a dim view of beetle larvae drilling tunnels in trees, claiming that this ruins otherwise “valuable” wood. Such anthropocentric views are myopic, for they exclude the needs of all other living things and turn a blind eye toward the ecology of forests. Jewel beetles benefit forests as agents of decomposition; the tunnels that their larvae bore in dead trees provide important open pathways for other insects and for the introduction of fungal spores. The tunnels facilitate the exchange of gasses in the wood and furnish the perfect moist, insulated, dark environ for fungi to take hold. Fungi are crucially important to living trees, to the health of the soil, and for their leading role in the recycling of nutrients via the decomposition of dead trees and other organic detritus. No forest on Earth can exist without fungi and decomposition.

This maze of tunnels was bored by jewel beetle grubs in a dead limb on a living velvet mesquite tree. Read the text above to discover why these tunnels are so beneficial to forest ecology.

This is a limb that was cut from the same tree as the one in the preceding image. However, this limb was cut when it was alive. Note the scarcity of holes and tunnels. Most jewel beetles lay their eggs only on dead wood, but there are a few exceptions to this rule.

Here in the desert southwest, jewel beetles are usually easy to find almost any place where trees are present. I have also found them rather often in upland desert habitats – areas that are essentially treeless. Buprestid beetles fly into these places seeking nectar and pollen meals from the wildflowers and flowering shrubs that grow there. Thus, they provide another important ecological function by acting as pollinators.

A Fascinating New Bird Appears

A few months ago, an unfamiliar bird call became part of the daily biophony here on our home acreage in the Middle San Pedro Valley. As an ever-curious naturalist, I had to know what bird was uttering those strange calls. My wife, Kathleen, had noticed it too. The bird called frequently in the early and late hours of every day, taunting us with its unique, three-note call.

Binoculars in hand, I went looking. I slowly approached in the direction of the sounds, looking patiently and carefully. The local habitat consists of a mature forest of velvet mesquite trees. The sound seemed to be originating up in those trees, but no matter how much I searched, the bird remained unseen. Most often, as I approached too closely, the mystery bird would exit stage left and start calling from a new, more distant location. I tried on another day, and another. Every time, the maker of the calls remained elusive and sequestered.

Velvet mesquite bosque, the woodland where the mystery bird appeared. This is an image from the summer months.

One morning, after hearing the unseen bird again, Kathleen and I decided it was time to explore the  xeno-canto website. I know of no better website when it comes to searching for bird sounds; readers can find it here:  https://www.xeno-canto.org  

I had a growing hunch that we were hearing a thrasher…when we listened to the recordings of crissal thrashers, both of knew that the enigma had been solved.

The crissal thrasher visiting our bird bath on a cold morning when the water had frozen solid. Crissal thrashers average 11 1/2 inches in length. This species is known to form pair bonds (in preparation for the spring breeding season) as early as January. Just two days ago, I noticed that our thrasher had found a companion…

Why hadn’t I seen the bird? I had been looking up in the trees when I should have been looking down, at or very near ground level. The bird seemed to have the ability to “throw” its voice, making the calls sound like they were coming from above. Once we had learned the identity of the bird, we realized that we should have been searching for it on the ground, not up in the trees. Now, we see the thrasher every day as it hides beneath graythorn bushes, foraging for food.

Graythorn is indeed very thorny. Meant to discourage consumption by mammals, the thorns protect the plant, but when it comes to birds, these thorns are an attraction. They spell security from predators, especially raptors.

Crissal thrashers spend much of their time beneath thick cover, using their long, decurved bills to dig and rake away soil and duff in search of insectivorous food. Locally, these birds appear to have a very strong connection with graythorn bushes. Graythorn (Ziziphus obtusifolia) is the most common understory shrub in local mesquite bosques. It grows dense, tangled, thorny foliage, furnishing the perfect place for shy birds to seek cover in. I cannot overstate the ecological importance of these plants with respect to bird life. Many species of birds hide in graythorns, feed from the plant’s abundant berries, or nest deep within its thorn jungle of tangled branches.

At the time of this writing, the graythorn bushes outside my windows are in full flower. The blossoms are minuscule.

After the flowers have been pollinated, berries grow on the graythorn bushes, providing an important food source for many local birds and mammals.

This winter, the Middle San Pedro Valley has been inundated with unprecedented numbers of white-crowned sparrows. There are hundreds on our land every day, and in many other places as well. I cannot walk by any graythorn bush without flushing a throng of white-crowns from within. Like the thrasher, they forage on the ground and use graythorns for cover. Security is imperative to all small birds here, for bird-hunting Cooper’s hawks are present almost every day. 

A HOPEFUL NEW YEAR, WINTER IN THE SAN PEDRO VALLEY, AND AN ARTIST’S VIVID EXPRESSION OF THE RIVER

The promise of coming  vaccinations, a new president, and the start of a new year have me full of hope… a state of mind that had faded considerably during 2020, a year marked by tragedy, social division, societal unrest, and a steadily worsening global pandemic. 

Here in the Middle San Pedro Valley, the season of winter is at hand, although the use of a term like “winter” in a place like this is a stretch of the word. The coldest temperature I have ever experienced here was only 8°F., and snow rarely falls in the valley floor. The image above was taken on a winter morning when a rare  blanket of fog had smothered the riverbottom forest with its cool, moist embrace. Fog is almost as rare as snow here. When fog does occur, it is a very transient affair, for desert fog most often dissipates into invisibility very quickly as the day warms.

A full moon casts its light on a stand of winter saguaros.

A few years ago, five inches of fresh snow fell overnight, gracing our bosque with a mantle of gleaming, sparkling white. I could not resist taking an early morning walk in order to read the very best of nature’s newspapers, for the goings on of every bird and mammal were written plainly in the snow. I encountered fresh tracks of various songbirds, quail, coyotes, a raccoon, mule deer, javelina, mice, cottontails, jackrabbits, and more. Following a set of roadrunner tracks (they are quite distinctive) I came across a sight I had never seen before: a roadrunner perched in a snow-covered mesquite tree.

I met with this well-chilled roadrunner perched in a velvet mesquite tree on a snow-graced morning.

Nature has forever been a source of inspiration for artists. There are scenes along the San Pedro River that could captivate any artist’s mind. Last month, an unforgettable gift arrived in our mail, an original painting crafted by none other than my brother, Rick. He and I had spent some time hiking in the riverbottom woodlands one fine spring day, when the river was alive with color and light. We stopped for a break at one of my favorite spots, a place that left its mark in my brother’s memory. Rick captured the essence of that place beautifully in this painting. What a gift!

“San Pedro Reverie,” by Rick Waldt.

A Big Buck in His Prime, New Life, and Rescued Wildlife

Winter brings many changes to the activities of our local wildlife. Mule deer move into the mesquite bosques to feed and find shelter. Last year, a magnificent buck lived here, in the company of many does. On a late December afternoon, he stepped out into the light, his neck characteristically swollen in the midst of rut, muscles rippling beneath a sleek coat of winter fur, polished antlers gleaming.

During these stressful times when so many lives are being lost due to the pandemic, it is reassuring and soul-warming to witness death’s opposite: new life coming into the world. A few days ago, I looked out my window to see a herd of javelina, some of them less than 20 feet distant, heading for our bird-feeding area. At this time of year, this group of nearly 20 javelinas visits our place every day and also during the night – seeing them was no surprise, were it not for the newcomers. Several of the adult females had tiny young in tow, varying in age from one or two days to about a week.

Baby javelinas follow closely behind their mothers. Unlike many other native mammals, javelinas do not have a set time of year to give birth, but several females have appeared here recently with newborn young.

When javelina are very young, they often remain nearly hidden beneath their mother’s bellies. They are so tiny that it is easy to miss them as a herd wanders by. I have never pictured adult javelinas as cute or endearing, but a mere glance at one of their stubby-legged babies can quickly reshape one’s views. Those little buggers are, in a word or two, downright cute. They can become otherwise as adults, fouling bird watering dishes, forcing any attempt at gardening in this valley to include stout fencing, and eating much of the bird seed that we scatter for our avian friends. On one occasion, our dog was nearly killed when it charged directly at a full grown javelina. In a split second, the dog was howling in pain as it returned at top speed with a life-threatening gash. Javelina are powerful and deceptively quick. They are well armed with a set of formidable, self-sharpening tusks. The poor little dog simply did not know any better. I did not reach for a rifle after the event occurred. The javelina was simply defending itself; in my mind, it had as much right to be on our land as we do. “Our” land is a place shared with other life. Enough said.

A javelina explores the world with its mother only days after its birth. Female javelinas are protective of their young, as all good mothers are. It is wise to give them room when very young offspring are present.

A year ago, another visitor appeared on a cool winter morning, an animal in serious distress. A hooded skunk had been lured by curiosity to the edge of an empty pool on our property, where it slid down into the bottom, only to find itself suddenly trapped. The vertical walls of that small pool are 5 1/2 feet high. Skunks are not built to be high-jumpers or cliff scalers. Normally, I keep an escape ramp positioned in the pool; a long 2×6 board. I had removed it the day prior when I had cleaned some debris out of the pool, but for whatever reason, I had not replaced it afterward. As soon as I discovered the trapped skunk, I replaced the ramp, sliding it down into the pool gently so as not to put the animal into defense mode. It did not take long for the skunk to walk up the ramp, out of the pool’s clutches.

Empty pools are wildlife traps. A simple escape ramp can make all the difference. Such ramps are also recommended for livestock watering troughs, allowing birds and other small animals a way to get out. A small amount of kindness can go a long way. Here, the hooded skunk ascends its way to freedom.

Once free, the skunk began to amble about, seemingly unruffled by its prior confinement. It was searching for food, and hardly paid me or my wife any mind as it stood less than ten feet from us. I have encountered other hooded skunks in the valley before…every meeting with these creatures had left me feeling that they were utterly inoffensive and little concerned with my presence. Some neighbors reach for a shotgun when  skunks come near their dwellings. Doing so shows a distinct lack of respect for other life and a lack of knowledge when it comes to coexisting with certain wildlife. Much like rattlesnakes, skunks are shy and inoffensive, unless they feel threatened. I know that if I were as small as a snake or a skunk, I would want some potent defensive measures. The rules are simple: maintain distance between oneself and such creatures and leave them alone. Maintaining distance assures one’s self protection. Leaving the animals alone and undisturbed shows respect.

Hooded skunks grow tremendously long tail hairs, a beautiful hallmark of their species.

Skunks bring special distinction to this part of the nation, for their kind are represented by four species here: striped, hooded, hognose, and spotted. Five species of skunks inhabit the United States. Only in a small part of southern Texas, southern New Mexico, and southern Arizonado the ranges of four of the five species overlap.

The skunk was in no hurry to run away after it was free of the pool. It wandered slowly, searching for food, as we stood watching less than ten feet away. This creature was mellow, inoffensive and beautiful; never once did we think we might get sprayed.

Rain Graces a Thirsty Desert and Four-footed Winter Company

For the past three months, hardly a drop of rain has fallen here in the Middle San Pedro Valley. This is, after all, a desert region, or nearly so – deserts are defined as areas that receive less than ten inches of precipitation per year. Here, we get a tad more than that. 

A typical rural driveway in the Middle San Pedro Valley; no street lights, no signs, and most of all NO PAVEMENT.

When the skies turned darker and darker shades of gray a few days ago, I was overjoyed. The land – and its life – has been under duress in southeastern Arizona. The past summer “monsoon” season yielded very little rain. So, when it finally began to rain earnestly on, of all days, my birthday, it felt like an exceptionally wonderful gift. As I stepped outside at dawn that morning, the air bore the rich, humid smell of rain and earth and wet leaves. I drew in big lungfuls, savoring the feel, the coolness, the dampness. For most Americans, rain is no big deal, a common part of life. Here, it is always something to be reverently grateful for.

After the rain, the floor of the mesquite bosque (Spanish for the word “forest” or “woodland”) was covered with millions of tiny velvet mesquite leaves.

The ground had changed color in two ways; it had turned darker  from the thorough soaking, and had also turned green, carpeted with millions of minuscule velvet mesquite leaves that had been unleashed from the trees by the pelting raindrops. The cyclic path of nutrients from soil to trees and back to the soil lay exposed at my feet, exemplified and accelerated by the rain.

The leaves of velvet mesquite are very small, but they grow in multitudes on the trees, providing a crucially important component of this hot, dry desert ecosystem: shade.

A few hours after dawn, a group of mule deer appeared. They are part of a small herd that has taken up residence in the surrounding mesquite bosque for the past several years. We always welcome their company and never consider them as our “guests,” for they and their kind have been here long before us or our forebears. If anything, we are honored to be guests in their home.

A group of mule deer appeared not long after the rain, foraging on mesquite pods and pigweed (Amaranthus palmeri).