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.
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.
This has been one of the driest and hottest summers I can recall here in the Middle San Pedro River Valley. During “normal” summers, monsoon rains arrive between the middle and the end of June and continue through August and much of September. The two previous monsoon seasons brought us a welcome abundance of rain, but this year has remained very, very dry. Daytime highs for the past six weeks have averaged around 106°F., with more than a few days reaching 110° or higher. This year’s highest temperature registered at a crispy 115°F. on July 17.
Our mesquite bosque remains dry, the understory of dense London rocket plants yellowed and brittle. Usually, by the end of July, this scene should be bursting with vivid green growth in the form of Amaranthus palmeri and many other native plant species.Despite our xeric summer, velvet mesquite trees in our bosque have produced a nice crop of pods, followed by a second flowering during the past couple of weeks. The trees are drawing on water from last summer’s abundant storms; mesquite has the rare ability to transport water in both directions within its extensive, very deep root system. Water can be transported deep underground and stored for later use. A fresh splay of velvet mesquite blossoms perfumes the air and reminds us that desert plants have evolved uncanny mechanisms to stay alive and even thrive under dry, difficult conditions.
Mesquite blossoms lead to garlands of bright green pods growing from pendant branches. Mule and whitetailed deer love to feed on low-hanging bunches of these young pods. When ripe, the seed pods turn yellow and fall to the ground. There, they become one of the most crucial and nutritious wildlife foods in the entire ecosystem, eagerly fed upon by a very long list of native animals from mice to coyotes to bears and many more.
Despite the drought, this was a banner year for a widespread local species known as catclaw acacia, Acacia gregii. (See the photos in my previous blog post.) Throughout the valley, these large shrubs/small trees flowered explosively. The scent from their blossoms is intoxicatingly wonderful. Much like mesquite pods, the seed pods of acacias are fed upon by a wide variety of native wildlife.
Dry conditions leave fine coatings of dust on our driveway – an excellent newspaper that I strive to read daily. This summer has revealed tracks of mice, kangaroo rats, gray foxes, coyotes, raccoons, mule and whitetailed deer, a cougar, hooded skunks, quail, doves, and other birds including this trackway of a Chihuahuan raven.A closer look at the raven’s tracks reveals their relatively large size, distinctively lobed feet, and shallow drag marks made by their posterior claws.
A mystery…last week, I noticed something I had not seen before: dense clumps of small, black native bees forming in certain graythorn (Zizyphus) bushes. I have no idea what is going on here, nor what species these bees are – there are well over 1,200 species of native bees in this ecosystem, representing the richest known bee fauna in the world.
I found this adult giant mesquite bug (Thasus californicus) roaming under my ramada the day before I posted this blog. These are large insects that are true bugs (Hemipterans) as opposed to a type of beetle (Coleopterans).
A lateral view of the mesquite bug reveals the tube-like mouthpart that it uses to feed on plant liquids. The tube is inserted, syringe-like, into the stems of plants. These specialized feeding tubes are a primary characteristic that separates true bugs from beetles.
Prior to maturation, giant mesquite bugs exist in the form of wingless nymphs. The nymphs form colonies that feed on liquids from various species of trees and shrubs. The nymphs go through several instars before finally transforming into adults, all of which exhibit these very bright red colors. The nymphs are protected with self-manufactured noxious chemicals that make them taste bad to predators, hence their aposematic coloration.
Arizona’s smallest mammals are shrews; I found this one – dead but still warm – on the floor of our bosque. This species is known as the desert shrew, Notiosorex crawfordi. Shrews are among the most highly energized, frenetic mammals on Earth. They require remarkable amounts of food – up to nearly half their body weight on a daily basis. They almost never stop moving, constantly on the hunt. I wonder how they have time to dream.
This sight greeted me a few mornings ago, when I walked outside just after dawn to see this giant centipede (Scolopendra heros) clinging to the wall of my adobe building. The broom handle gives a sense of scale. This one was just under seven inches long – and they get bigger than this, up to nine inches in length. Very large specimens measure around an inch in width across their backs, are equipped with formidable pincers, and can move at astounding speeds.
High winds snapped this velvet mesquite trunk at the location of a cavity hollowed out by Gila woodpeckers. I have seen such tree breaks many times, both locally in this southern desert and in the northern Rockies. There is a complex relationship between cavity-making birds and their varied roles in forest ecology that may be more important we know.
A close look at the exposed woodpecker cavity shows the remnants of a successful nesting season. Last month, a pair of ash-throated flycatchers raised a batch of young within the sheltered confines of this tree cavity.
This image should be entitled “HOPE”… a series of empty, dry water buckets under my roofline, hoping and waiting for the summer rains. Why collect rainwater when we have a well, particularly summer rain water? The summer storms often feature stunning amounts of lightning, which allows substantial amounts of elemental nitrogen to be carried from the atmosphere (via rainfall) down to the ground, where it greens the Earth. All gardeners should learn that summer rain water collected after lightning storms works magic on plant growth.
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.
Last week, two friends and I embarked on a short hike up a roadless drainage in an effort to scout the area for a group hike that I will be leading in a few days. We were also hoping to explore an amazing slot canyon that one of my friends had discovered more than a quarter century ago.
I refuse to publicly divulge the location of the canyon for several reasons. First, there is the matter of deep respect for the many living things that call the canyon and the surrounding area home – a rich community of undisturbed native plants, insects, snakes, birds, mammals, etc. Secondly, when wild places are publicized, more and more people inevitably go there. Trails get carved into fragile desert soil. Litter appears…candy wrappers, used toilet paper, beer cans, broken bottles and spent shell casings from those who carry weapons. Initials get carved into once pristine stone walls and the garish rudeness of graffiti mars the sanctity of the place. Sensitive wildlife species leave or disappear altogether. All I will disclose is that this area is somewhere within the 4,720 square-mile San Pedro River Drainage in southeastern Arizona.
Our walk led up a wash (desert speak for a streambed that remains dry during most of the year) under cloud-flecked skies on a warm spring morning. Less than a mile in, we came across the signature tracks of what has become the region’s apex predator (next to humans). Just two centuries ago, that role would have taken a back seat to the indigenous people, jaguars, wolves, and grizzlies that thrived here prior to the arrival of large numbers of Euro-Americans.
This track appeared in soft sand, made by an adult cougar that had walked by the night prior. The cat was a female – mingled with its tracks were the tracks of a single cub that had become large enough to be thinking about going out on its own before long. Mountain lions are primarily crepuscular and nocturnal hunters. They are incredibly adept at hiding quietly – even in scant cover. They utilize large home ranges. The combination of these factors adds up to a furred ghost that very few people ever get to glimpse in the wild.
March is a month that spurs changes in southern Arizona’s avian world. As we walked, turkey vultures soared overhead, recent arrivals from their wintering grounds. Mockingbirds and cactus wrens were singing with newfound spring zeal. Two other recently arrived migratory species made themselves known- one by voice, a gray hawk – and another by sight, a large, lone, black-colored bird flying over a distant ridgetop. Its silhouette formed a distinctive, familiar shape. The combination of broad wings and a wide, short tail nearly touching the trailing edges of the wing feathers strongly suggested a common black hawk. As the raptor curved its flight path, banking its body, the tail suddenly flashed a broad white band, cinching the identification. The hawk had just appeared here from migration; had we been in the same area only days sooner, it was likely that we would never had seen it.
Not long after the black hawk, we changed direction, exiting the wash to ascend a gentle slope leading toward my friend’s slot canyon. Two of us followed as he led the way to the base of some sandstone cliffs…
From a distance, these large, vertical rock outcroppings looked enticing, but the entrance to the canyon was not yet visible.
As our viewpoints changed, the entrance to the slot was revealed. Just inside the canyon’s mouth was this western white-throated woodrat palace. The rodent’s nest (it was currently occupied) can be seen at the bottom of the rock wall. Woodrats literally evolved to prefer steep rock faces as integral parts of their habitat. They are highly adept climbers. Note the whitish stains on the rock wall a few feet above the nest, and the cavity in the rock face farther above with similar stains issuing from its base. The cavity is a frequently used hiding place for the rats, who mark their nocturnal trailways with frequent squirts of pungent urine. Everyone knows about stalactites and stalagmites, but did you know that they can be made from urine? This is a closeup view of the white-stained area a few feet above the rat nest depicted in the photo above.
Centuries of frequent use by woodrats depositing countless dribbbles of pee has caused actual stalactites to form. These are smaller than the stalactites often seen in caves (formed from water-borne mineral precipitates) but they are stalactites nonetheless. A series of funnel-shaped walls towers above the person seated at the end of this short but fascinating canyon.
The view from inside looking straight up at a cerulean slice of sky. The person aiming her camera gives a sense of scale to an otherworldly realm. Multiple funnel-like chimneys form the back of the canyon, where sediment-laden water has carved repetitive shapes in the sandstone, inching its way back through time. These cone-shaped circular funnels are narrow at the top, then widen progressively as they descend to the bottom. This has me mystified. Natural water funnels the world over form with wide mouths at their tops that narrow as the funnel goes down. The shapes in this photograph depict inverted funnels. Even when I try to understand this via methods that include something like the Coriolis effect, they do not make full sense to me. There are numerous singular rock funnels like these in this region, but few places feature multiple funnel shapes like this canyon does. Our hike revealed another rare part of this wild landscape: a saguaro with multiple cristate heads. It will be interesting to watch this cactus as its deformed meristems grow larger in coming years.
The Middle San Pedro Valley sprawls across nearly one million acres of undeveloped, unfragmented land in southeastern Arizona. Its slopes and woodlands, bajadas and ridges have been rimed with frost every dawn under the abbreviated touch of winter’s Sun. Days are short. The land stands hushed and still with its seasonal absence of many birds, reptiles, and other forms of life. Nonetheless, there are many good reasons to get outside and walk the land. January and February have brought a few surprises, particularly in the way of unexpected sightings of locally uncommon birds.
In late January, five purple finches began frequenting our bird feeders, thinking they were well concealed within mobs of house finches and lesser goldfinches. My wife’s sharp eyes picked them out of the crowd. In 20+ years of avian record keeping in this valley, that was the first time we had ever seen purple finches. Another species that has been sighted sparingly here during the winter months is the American robin. For reasons that remain a mystery to me, we have been inundated with robins this winter. They bring me many fond memories of their near-constant presence during past summers when I lived in the northern states.
Speaking of thrushes, another bird that I had never seen in the valley before has arrived to grace the nearby riverbottom woodlands this winter – a Townsend’s solitaire. A friend and neighbor, Tom Talbott, first sighted one about a week ago in the forests along the river not far from our home. Tom is a highly skilled birder and a masterful wildlife photographer. A few days later, walking the same reaches of the river, a friend and I also saw a solitaire. News has been spreading of numerous sightings of this species in areas just a few dozen miles to the north.
A Townsend’s solitaire perches quietly in branches overhanging the channel of the San Pedro River. These elegant thrushes are common residents of timberline forests high in the mountains of western Montana, where I would meet them again and again as I led groups of hikers during the summer months. Their songs are unique and unforgettably angelic, like no other bird I have known. Photo courtesy of Tom Talbott.
Not far from the solitaire, we found this great horned owl snoozing within the branches of a Fremont cottonwood. These owls are remarkably capable predators whose list of possible food items exceeds that of any other North American owl. Among the creatures that great horned owls have been known to prey upon include insects, amphibians, various reptiles, mice, rabbits, domestic cats, small dogs, ducks, skunks, and even porcupines.
Mid-January brought us over an inch of rain in the valley floor during one winter storm. Rainfall amounts were much higher in the nearby Galiuro Mountains, resulting in a strong winter flow for Hot Springs Wash. Such flows during the winter months are rare.
The rain enabled millions of dormant London rocket (Sisymbrium irio) seeds to sprout, providing a new source of food for wildlife while greening the floor of this mesquite bosque with the glowing color of new life.
Large numbers of these small white puffballs erupted from the ground under mesquite trees after the rain. Fungi are becoming known as some of the most important organisms on the planet. The mycorrhizal filaments of many species of fungi form mutually beneficial associations with tree roots, for example. No forest on Earth can exist without such subsurface fungal alliances.
A hooded skunk wandered under my ramada one night, leaving its signature behind in the form of these tracks made in fine, dusty soil. Note the track pattern as the animal was walking at normal speed.
A closer look at the skunk’s footprints. Even though skunks are plantigrade mammals, the heels on their back feet often do not register in their tracks, as seen here. (The hind foot is to the left, front foot to the right.)
I discovered this torpid spiny lizard spending the winter brumating underneath a plastic tub that had been set outdoors on the ground. The lizard was found at ground level, not dug in below the frost line. Temperatures here routinely dip into the teens every winter. I was taught that reptiles must spend winters below the frost line, because otherwise they would freeze and die. I have also seen a pair of diamondback rattlesnakes spending the winter under a board in an open barn. Apparently, what I was taught cannot be correct – it seems clear that these reptiles can endure a fairly substantial amount of freezing.
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First, a note of sincere, heartfelt thanks to everyone who so generously contributed to my appeal for a new pair of binoculars! The appeal was a great success – I am elated to say that the new binoculars are in my hands, and they are absolutely stunning. I cannot adequately express my gratitude for the gift of such an exceptionally important tool that will enable me to continue doing what I do as a naturalist. I’m beaming as I write this. 🙂
White-nosed coatis are one of the most charismatic and fascinating native mammals of SE Arizona. Bands of them are fairly common in the Middle San Pedro Valley where my family and I reside, but I have rarely documented their presence on our property. Only days ago, my wife saw a lone individual close by our home. Two days later, a band of coatis crossed our little acreage unseen, but they left abundant and unmistakable signs of their presence.
Just south of the Arizona/Mexico border, coatis are known as chulos (there are several other Mexican names for them); in the US, most people refer to them as coatis or coatimundis. Taxonomically, they are known as Nasua narica. Among a number of their unique features, coatis are one of the world’s very few social omnivores. (Can you think of any others? Offhand, all I can come up with are humans and meerkats.)
Some two decades ago, when I first began to roam the wildlands of this valley, I was not sure how to separate the tracks of coatis from those made by one of their cousins, the raccoon. I had heard that they were difficult to distinguish, but that soon proved to be incorrect. This exemplified one of many things that a naturalist must learn by direct experience out in the field, for the great majority of tracking books fall far short of being accurate, reliable sources of information.
So, how does one recognize the differences between the tracks of these two animals – tracks that, ostensibly, can look a lot alike?
Fresh coati tracks in fine dust under my ramada reveal toes positioned tightly together with consistent thickness along the length of each toe.These raccoon tracks, particularly those made by the front feet, (at left), show diagnostic shaping and separation of the toes. The toes are proximally narrow in comparison to their distal ends, where they widen into bulbous tips with relatively short claws. Once this distinctive toe shape is recognized, misidentifications between well-defined raccoon and coati tracks can be eliminated.When a band of coatis forages, they commonly pause in certain areas where they make numerous shallow digs for food such as beetle grubs. The band that visited here just days ago left this characteristic array of holes behind. (Note the 6-inch ruler included in the photograph for scale.) Skunks are common locally, and they also dig for a living, but not in this fashion.On a hot summer day years ago, I photographed this chulo sign along the banks of the San Pedro River. The coatis had been digging into the sandy riverbank, leaving some spectacularly long claw marks in addition to the excavated holes.
Another pair of native mammals that can leave similar signs of their presence are mule and whitetail deer. One of several ways to distinguish their signs comes into play when these animals are moving at high speeds. Whitetail deer gallop when they run fast, but mule deer tend to stott when they are in a hurry. Stotting refers to an upward leaping motion where all four feet leave the ground at the same time and land at roughly the same time – a type of movement that most people would describe as a hop. And what a hop it can be!
A mule deer buck moving at high speed left a set of tracks near our home last week, beautifully defined in rain-moistened soil. This deer had easily leapt over two fencelines in less than several dozen yards and had clearly been moving very quickly. I laid a measuring tape on the ground along the deer’s trackway – it revealed a single stott that measured 19 feet, three inches in length. No problem for an adult mule deer.
Here are the four feet of the buck at one of the points where he landed. The deer did not stop here – these tracks were part of a series of energetic stotts. Note that the front feet are positioned ahead of the hind feet, (relative to the direction of travel). If the deer had been a galloping whitetail, this order would be reversed, (rear tracks to the front and front tracks to the rear). Note the spread clouts of the hooves. Deer (and many other mammals, including barefoot humans) autonomically spread their hooves like this in order to prevent slippage as they gallop or stott.
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A few evenings ago, an uncommon view from my desk window engendered delight and a deep feeling of gratitude. The scene encompassed a wild mesquite bosque, standing tall and green in summer’s refulgence…a gentle, drizzling rain was floating its way to the ground, suffusing the air among the stout trees with the magic of a fine mist, colored soft in fading light. The land was coming alive, replete with the promise of sprouting plants, emerging fungi, and the rising scent of moist duff. A water-borne resurgence of desert life was in the making.
During the past few weeks, more rain has fallen, resulting in a cavalcade of change, a water-borne eruption of desert life. Flowers are blooming and creatures are stirring, many of which cannot be seen at other times of year. Giant millipedes are crossing roadways and threading their way through the woodlands, tarantulas are out of their burrows roaming the landscape, harvester ants are forming great clouds of alates bent on their one-day-per-year mating spree. Sonorous calls of amphibian passion are ringing through the night after every substantial rain. “Monsoon” as locals know it, is the one season that defines these lands and the ecology of southeastern Arizona more than any other. Arizona without its monsoon would be akin to Alaska without a winter.
One of many creatures that are revealed during this season is a small, nocturnal lizard with semi-translucent skin like gauzy velvet, big eyes with vertical pupils and movable eyelids, and the very rare ability (among lizards) to vocalize. Once encountered, the western banded gecko is not soon forgotten. More than once, I have heard the word “cute” applied to this beguiling little creature that rarely grows to more than four or five inches in length and remains hidden during daylight hours.
I discovered this little gem sheltering under an old piece of plywood. This banded gecko had lost its tail sometime in the past – the new one grew back lavender in color. A plump tail like this one indicates a good state of health, for the tail stores fats and water for the animal to draw upon during lean times, much like the tails of Gila monsters.
When predators chase after lizards, the first part of the lizard’s body that they make contact with is often the tail. In evolutionary response to this, many lizards have developed special abscission layers in their tails. Once contacted, the tail breaks off, leaving predators detracted by a wiggling morsel while the main course absconds to safety. Banded geckos have tails that break off with a very, very light touch; hence, I recommend against handling them.
When threatened or disturbed, banded geckos often curl their tails over their backs. Such posturing mimics the scorpions that they share habitat with, potentially scaring off some would-be predators. Banded geckos can also utter an audible squeak when frightened, making them one of the few lizards in the world capable of vocalizing.
During late July, the mass of tadpoles in our bird pond (see the previous blog post) transformed into toadlets in a matter of only ten days. The tiny young amphibians are now hopping their way into the surrounding woodland, disbursing at night when temperatures are cool.
This minuscule toadlet was photographed during its first day out of its natal pond, where it had spent the initial ten days of its life as a wriggling tadpole. At this stage of their lives, Couch’s spadefoot toads (Scaphiopus couchii), are tiny and vulnerable, fitting easily atop a mere dime.
On a warm early morning in mid-July, I took a walk and discovered an abundance of white-lined sphinx moths (Hyles lineata) almost everywhere I went. Most sphinx moths do their flying at night, but these moths were out in direct sunlight. They were specifically targeting wolfberry (Lycium spp.) bushes. The wolfberry was in flower, and the moths were hungry for nectar. With unerring accuracy augmented by rapid, graceful flight, they were moving from flower to flower, hovering at each one to insert their long tongues for sips of nectar.
A white-lined sphinx moth hovers over a wolfberry bush, deftly inserting its long tongue into the tiny white flowers to feed on nectar.
Note the bend in the moth’s tongue, a common trait among many species of sphinx and hawk moths.
White-lined sphinx moths have a very wide distribution that includes most of the United States. In some areas, their tongues are considerably shorter. Here, as they coevolved with certain types of nectar-rich flowers bearing long corolla tubes, their tongues adapted over time.
Since the first of this year’s summer rains on June 18th, we have received 4.25 inches of precipitation. Here is an image of our bosque taken just before the first rains.The same area, photographed yesterday. The difference is clear – the greening understory is composed primarily of pigweed (Amaranthus palmeri), a native plant that is of great value to a wide variety of birds and mammals. If the rains continue, this vivd understory will be capable of reaching heights of six to seven feet.This is what is left of a pigweed plant that grew after last summer’s monsoon rains. Pigweed retains much value to wildlife even after it has died and desiccated to a state like this one. Note that the plant has been recently fed upon, and that the cuts at the tips of each stem are sharply defined, cut cleanly at a steep angle. This is a signature left by the incisor teeth of a black-tailed jackrabbit. Nearly all rodents and lagomorphs (members of the rabbit order) leave such distinctive cut marks when they browse on similar types of vegetation. If deer or javelina had done this, the cuts would be rough with frayed edges and not cut at such steep angles.
Our area, the Middle San Pedro Valley, is served by a single dirt road that frequently endures serious damage after monsoon rain storms. I photographed this large wash near our home shortly after dawn, several hours after the flood had crested. The wet marks along either edge reveal a surging flow of flood waters that had crested at over 150 feet in breadth and four feet in depth. Flows this strong are quite capable of quickly carrying away almost any vehicle, even very large trucks.
This year’s monsoon got off to an early start in mid-June, but thus far, we have received just 2.98 inches of rainfall. Many storms have passed by, missing us by only a few miles. Hope for more rain is justified, however, because the summer monsoon season still has a couple of months to go. Summer rain always brings a wonderful blooming of life to this arid landscape, most of which cannot be witnessed at any other times of year. Here is a brief gallery of some of those recent gifts…
The floor of the local mesquite bosque has been bereft of greenery throughout the autumn, winter, and spring. One of the first substantial monsoon storms brought color to the woodland floor – an effusion of fresh, young plants erupting from the soil. Also visible in this image are mesquite pods. Millions of these highly nutritious pods have fallen from velvet mesquites in the valley during the past couple of weeks, providing a keystone food source for a tremendous variety of pod-eating wildlife. Rain cleans and wets the ground surface, providing a crisp, fresh record of the presence of local wildlife, like this mule deer buck’s trackway. As is the case with most quadripedal mammals, these tracks show substantial dimorphism: the larger track represents a front foot, the smaller a hind foot. The remains of a well-chewed mesquite pod reveal the place where a rodent fed the night before. This one was most likely the work of an Ord’s kangaroo rat. Tarantulas remain hidden and mostly inactive during much of the year. Summer rains bring them out of their burrows. This is a full-grown (palm-spanning) male Arizona blond tarantula, Aphonopelma chalcodes. If I am not mistaken, these are western subterranean termites, Reticulitermes hesperus. After the first strong summer rain storm, these insects emerge in spectacular swarms to embark on their aerial, one-day-per-year mating flights. Termites are among the most essential of all insects in the desert southwest, for they are primary decomposers of plant materials, recycling essential nutrients back into the soil. A western diamondback feeding on a lesser goldfinch at our bird pond. Some people may find this image disturbing, but such a viewpoint implies an abiological bias…the cute little bird and the horrible, scary snake. Both are native residents of this ecosystem, both are equally welcome on our property, and both must eat to survive. An ornate box turtle, Terrapene ornata, stationed itself under a suet feeder one day and revealed something new – box turtles love to eat suet! Bits and pieces fall to the ground as woodpeckers and other birds feed on the suet block; these high-calorie morsels are eagerly consumed by other creatures, including ravens and nocturnally foraging mice. A heavy rain brought several Couch’s spadefoot toads to our bird pond. Females are typically colored with dark reticulations like this individual. Male Couch’s spadefoots are usually much more plainly colored. A first! This morning, our “bird pond” was wriggling with new life, a batch of spadefoot tadpoles! If these tadpoles survive to grow into adult toads, they will carry the memory of their natal pond’s geographic location, and will return to it to breed in future years. Another first for our bosque – a Gould’s turkey with young in tow. I had seen turkeys here before, but never a hen with her offspring. At dawn’s first soft light after a nighttime storm, there were a dozen or more white-lined sphinx moths (Hyles lineata) circling the small pool of water that constitutes our bird pond. The moths were alighting to drink – they disappeared soon after, as daylight strengthened. These are large insects with three-inch wingspans, equipped with powerful musculature that enables strong, rapid flight. This species ranges from Central American northward to Canada.
Early summer in the Middle San Pedro Valley has brought us some uncommon sights. One of our nation’s most dazzling – and sneaky – songbirds is the varied bunting. No larger than a small sparrow, varied buntings often appear black unless they are viewed at just the right angle in favorable light. They occur in small numbers here; we typically see only one or two of them in our bosque every summer. They are sneaky because we never know when they will appear, which is infrequently at best. A beautiful male will drop from the mesquites to grab a quick drink of water from our bird pond, then quickly disappear into the depths of the woodland, not to be seen again for days or even weeks.
My wife Kathleen photographed this male varied bunting through the kitchen window just days ago. When viewed from an elevated position (like our kitchen window), a blazing scarlet patch can be seen adorning the top of the male bunting’s head. This is no accident. Birds often view one another from above, so bright patches of identifying color on the top of their heads help them to keep track of who’s who. Photo by Kathleen Waldt. An even rarer sight here in Cochise County, Arizona comes in the form of another bunting species, the painted bunting. When this female landed at our water dishes in May, Kathleen identified it immediately. The males are among our most brightly colored songbirds, but females are far more subtle. The softly colored green back gives this one away.
Last week, a rare find presented itself in the form of a fresh Gila monster trackway etched into the fine dust along the side of our shop building. The only other animals that can leave similar trackways here are turtles, but a close look at this trackway leaves no doubt as to its maker.
I discovered this trackway less than an hour after it was made, but try as I might, I could not locate the Gila monster that made it. Finding Gila monster tracks is uncommon; finding an entire trackway like this one is downright rare. The animal that made these tracks was a young individual, roughly 9 – 11 inches in length. A closer look reveals distinctive footprints and a drag mark left by the lizard’s tail down the center of the trackway.
The month of May brought the expected blooming of saguaros, but this year the huge cacti did something very strange. Instead of crowning the tips of their trunks and arms with halos of blossoms, they grew flowers both on the tops and down the sides of their heavy arms. I had never seen this phenomenon until this year. Locals are saying that this is a response to the severe drought we are experiencing in the desert southwest. I want to know why the plants are behaving like this.
A very rare sight! Flowers extending far down the sides of saguaro arms. Normally, they are located only at the tips of the arms and atop the crowns of saguaros. Photo by Kathleen Waldt. Another rare sight in the form of a cristate saguaro. Like its neighbors, this one had blossoms sprouting down the sides of its arms.
