Tag: mammals

A Lizard with a Voice and More Monsoon Discoveries

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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.

An Early Monsoon Photo Gallery

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.

FIRST RAIN!! Early Summer in the Middle San Pedro River Valley

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.