The Dunes of
October 4, 1996
Notes from a birding trip through Mexico by Jim Conrad
northern Mexico's Chihuahuan Desert, about half an hour south of the US/Mexican border
between El Paso and Juárez, a Fronteras bus pulls away leaving me standing alone beside
the highway. The bus's curtains have been pulled while a gringo movie with car chasing and
gun shooting showed on eight video screens over head. The heavy darkness inside smelled of
industrial-strength disinfectant, nachos and aftershave.
As the bus pulls away a cloud of black diesel fumes fogs around me, but very quickly the sound of the engines grows softer and the fumes drift away. As my eyes adjust to the light and the new dimensions of things at last there's nothing but the quietness of the desert. What a change this is from the last couple of days!
When the sun went down last night I was on a Greyhound bus entering Dallas on I-30, coming in from the Northeast. All afternoon I'd been looking at low rolling hills and scrubby forests of oak and hickory. Last night as I slept there were stops in Abilene and Odessa, and we got into El Paso sometime around 4 AM. I walked across the International Bridge at dawn, bought some bean tamales, and ate in a little park in Juárez while Great-tailed Grackles clamored among the palms overhead.
There's no traffic on the road right now, the only sound being my own breathing, and the rustling of a light breeze around my ears. All this sunlight, the broadness and blueness of the sky, and this silence... I just stand for half a minute or so, looking around.
The village of Samalayuca lies to the west, a fifteen-minute walk down an arrow-straight, broken-asphalt, treeless stretch of little road. To the east, white sand dunes rise above a level plain of waist-high scrub. However, I can't say how far away the dunes are. Are they huge and far away, or small and nearby? For the first of what will surely be many hundreds of times this trip, I dig out my binoculars and take a closer look: Nothing jives with how things usually announce themselves and fit together and the question remains unresolved..
I pick up my backpack, walk across the highway, and embark on a sandy, two-rut track leading toward the dunes.
After about twenty minutes I can see by how much the dunes have grown that they must lie two or three hours away. The track passes a low-strung ranch house built of rough boards, rusty tin roofing and having only two or three tiny windows with heavy, dirty towels covering them.
Presently the sand road jags hard to the left, though the dune field looms more and more to the right. I abandon the road and take wildlife trails snaking through the scrub.
WALKING THROUGH SCRUB
The sky is blue with a white sun in it. Without haze, the sky reaches all the way to the jagged, stone-gray, ridge-horizon-frame. A good distance away the dunes glare so violently that they are almost white, even ghostly. They seem to hover over the blue-gray scrub with its spines.
A certain randomness seems to have set the dunes in their places. They are like circus tents beneath poles of varying heights. They are clustered, with the highest ones gathered in once place.
Two shrubby species comprise this scrub, Mesquite and Creosote Bush. Both grow waist- to head-high, and as I walk among them I notice that in some places Mesquite grows in pure stands while in others there's nothing but Creosote Bush and, still in other places, the two species mingle indifferently. There's also a lot of knee-high Sagebrush with its ash-colored leaves, a few mostly nonflowering desert wildflowers, and several kinds of grass. I am having a problem with the grass called Sandbur.
Sandbur grows about halfway to the knee and produces straw-colored fruits smaller than peas and bristling with hard, needle-sharp spines. Each spine is hooked at its tip, but the hook is almost too tiny to see with the naked eye. The hooked spines latch onto passing-by furred animals, and socks and trousers.
Several Sandbur spines have worked themselves through my socks and they're pricking my ankles. To remove them I sit down -- absentmindedly right onto some Sandburs -- and instantly I'm reminded of the most vicious thing about Sandbur spines: Their hooks are so tiny that they don't keep the spines from entering your skin, yet when you try to withdraw a spine, the hook anchors in your flesh, and pulling the spine out hurts much more than when it jabbed into your skin. By the time I recall the old trick of removing the burs with a comb it's too late to save my fingers.
INTO THE DUNES
Walking, walking, walking through the scrub, toward the dunes, the vegetation thins imperceptibly and eventually I realize I'm walking among old, very low dunes stabilized by the plants growing on them. The dunes figure on the landscape like lazy swells at sea. As I continue toward the higher dunes the swells gradually increase in size from less than knee high to over head high. Finally they give way along a well defined boundary to dunes mantled by plants only on their lower slopes, their crests being naked sand.
Inside the main dune field vegetation finally disappears leaving just windblown, shifting, glaring sand. From inside the dune zone it seems that there's just one very broad-based dune maybe five to ten stories high, but up the sides of this mother dune there climb scores of house-size smaller dunes. Maybe the mother-dune is two to four miles across and ten to fifteen miles long.
Having arrived, I just wander around, the wind blowing hard in mid afternoon, making my backpack's loose straps flap hysterically.
The starkness around me, the blinding sunlight, the heat, the choking clouds of sand and dust, stun me.
But what troubles me most is this: The landscape itself is uttering an ultra-base ommmmmmmmmm just like the sacred word the yogis use when going inside themselves.
HARRIS'S HAWK & KESTREL
I know it's a Harris' Hawk because in the sky's overwhelming brilliance I can barely make out a dark tail with a white rim and even patches of chestnut on the shoulders. I recognized the Kestrel because of its size relative to the Harris', and the typical streamlined falcon shape, with swooped-back wings.
The little Kestrel, with half the Harris's wingspread, easily outmaneuvers its adversary, but the Harris' keeps up the attack. The whole drama lasts no more than a couple of seconds, then they drop behind the mother dune's crest and do not reappear, and I am left to deal alone with the wind, the sun, the heat, and the blowing sand.
One dune after another, the sand that's pouring into my shoes burning through my socks... The heat, wind, and glare, and all I want to do is to set up my tent and crawl into its shade...
But pegging a tent in this wind is impossible. Again and again it billows and tries to fly off like a kite, more than once dragging me onto the searing sand. I peg one end and go to work on the other, but the pegs pull loose and the tent rages into my face. Gathering the tent into my arms, I go huddle next to a knee-high Sagebrush and simply wait. Hours I wait.
An hour before dusk the wind lays enough for the pegs to hold. I enter and lie on my back panting and sweating, feeling searing, banana-size sand-ripples beneath me. Gradually the wind subsides more, then the temperature plummets and finally a raw chill creeps into the air. Black shadows pooled in troughs between dunes swell until they overflow the tent.
When Jupiter hangs suspended in the western sky the air is like crystalline glass holding everything in suspended animation. Though no Creosote Bush is in sight, its medicine odor suffuses the air. I fall into a stunned, empty sleep.
At daybreak I peep from beneath the tent's flap to see what kind of day there is. In this first week of October the temperature stands at 57º F (14º C), the sky is clear, and the air is calm.
The passage from night to day takes place fast. In a matter of twenty seconds sunlight breaks over the eastern ridge and floods dune tops all around. One moment the desert is slate-gray and somber, the next, dune tops flair alive.
For a minute right after this high-speed dawn, from the Mesquite/ Creosote-bush zone surrounding the dunes, a pack of Coyotes calls -- not with dignified, lonely howls, but with silly sounding yelping and squealing, like half-drunk teenage boys..
As soon as there's enough light in the tent to read I pull out my map. The elevation here is about 4,300 feet (1,300 meters. That ridge to the east, I see, is the Sierra el Presidio, and according to the map it's only nine miles away (15 kms). To the west the ridges with clouds heaped around their peaks are the Sierra Boca Grande and Sierra las Lilas, 60 miles distant (100 kms). This western ridge had seemed much closer. The desert has tricked me.
The map shows that between here and the western ridges there's a vast plain of sand dunes interspersed with temporary lakes. I know the lakes are temporary because on the map the blue lines delimiting them are dashed. Streams leading into the lakes also are dashed, so they flow only after rains.
I love maps. I like the idea that right now I can tell you that I'm
at latitude 31º21'N, longitude 106º27'W, and if you're interested you can look in your
atlas and see exactly where I am.
With dune crests blazing, I walk along chilly, blue-shaded dune slopes. With immense satisfaction, before having even crossed the first dune, the desert's silence is shattered by a piercing, almost startling whit-wheet, enunciated like the "Hey, you!" whistle some people use to get attention. The call comes from a car-size thicket of yuccas atop a sand ridge connecting two nearby dune peaks.
Despite my slow approach to the yuccas, the whit-wheeter spooks and escapes to the crest of the next dune, landing starkly silhouetted against the glaring eastern sky, fairly galloping onto the ridge, kicking up a silhouetted spray of sand atop the silhouetted dune.
The running silhouette displays an eleven-inch long (28 cm) songbird with a curved bill and a longer-than-usual tail. Anyone familiar with American birds would know that it's a kind of thrasher. Circling the dune for a look at the bird's sunny side, I'm ready to say which thrasher it is after catching a glimpse of nothing more than its eye color, for it's the only thrasher in this part of Mexico with reddish-orange eyes, the Curve-billed Thrasher.
Except for its orange eyes it's a drab bird, the dark, dingy hue of a rag that's been used to wipe off a very dirty car. Filthy House Sparrows in sooty Third-World cities are this color. Indistinct streaks on the bird's chest show like curdles formed atop sour milk.
This dramatic appearance pleases me greatly. Even though the species is common in this region wherever sparse desert scrub occurs, I would never have seen it when I first started birding as a farmboy in Kentucky. The closest Curve-billed Thrashers come to my childhood home is central Texas, some 700 miles (1,100 kms) southwest of Kentucky.
This is something I've always done -- related plants and animals seen during my travels to the species I knew so intimately as a kid. In a way, the degree to which I always "feel at home" varies in direction proportion to how many plants and animals around me are the same I knew as a kid. When I see something like this Curve-billed Thrasher, I am thrilled by its exoticness.
Now, with an immense sense of satisfaction, I bring out my notebook and write:
Flying low, like a skipping stone striking upon every wave crest, the Curve-billed Thrasher departs for the Mesquite and Creosote Bush zone, and once again the desert is very quiet. In this dawn silence there unfolds a shadow show.
The sun surges into the open sky and the dunes' shadows withdraw into their troughs, all the while metamorphosing abstract forms. During the time taken for aesthetics on the right side to be absorbed, shadows on the left create a whole new theater to be reexamined, and when you finally absorb what's on the left, the right has changed yet again...
Sand grain by sand grain the wind has sculpted the dunes' crests, slopes and troughs. Shadows lie around these forms like patches of black silk jigsawed into long, sinuous patterns. This blending of shadow-and-light curlicues and long sweeping lines puts one into the mind of arabesques.
Now I understand the relationship between Arabic script and the desert's sand.
Footprints in the sand show that during nights a broad community of animals come and go. There are jackrabbits, mice and rats, a Kit Fox, lizards, insects, and critters I can't identify.
Sometimes pencil-thin ridges atop shallow tunnels begin nowhere, wander aimlessly, then suddenly end, and I have no idea who makes them, or why. Most tracks lead briefly in one direction, then jag for no apparent reason in another direction, zigzagging across the sand.
The Kit Fox, in contrast, travels in a straight line, over dune crests and into troughs. After thinking about it awhile, I realize that it makes sense for a fox to travel like this, to pop over dune crests, for among sparse grass and wildflowers down in the troughs there might be rabbits, rats, and mice.
At 10 AM a raspy call erupts from the next dune's slope. Something white perches there on a brown, decaying flower-stalk emerging from a wastebasket-size cluster of bristling, bayonet-shaped yucca leaves. The binoculars show an old friend, a bird I've known since I was a kid on the Kentucky farm, the Loggerhead Shrike.
It's a handsome bird and it's handsome not because of colors, which are merely gray, white and black, but because of the boldness of its patterns. It's mostly gray with a white throat, black tail, and black wings with white patches that flash during flight. And shrikes wear black face masks like cartoon characters robbing banks. For beginning birders, the black mask separates it from similar-looking Mockingbirds.
You expect hawks and owls to be hunters of small animals other than insects, but not songbirds like shrikes. Nonetheless, . Loggerhead Shrikes prey on rodents and birds as well as insects. Songbirds aren't supposed to have hooked beaks like hawks and owls, but even from thirty feet away I can see this shrike's upper mandible curving downward into a conspicuous hook.
Shrikes, like all other predatory birds, have the problem of keeping their prey stabilized while they dissect their prey. However, shrikes don't have the powerful feet that owls and hawks do to hold their prey, so shrikes sometime impale and immobilize their victims on sharp things like spines and thorns. I've often found mice and grasshoppers on cactus thorns and barbed wire spines, surely the work of shrikes. In fact, I don't think I've ever seen a shrike without there being something spiky nearby.
Once in Mississippi I spotted a Loggerhead Shrike perched on a fence surrounding a suburban home's backyard garden, and I thought I'd finally seen one away from all spines. But then I noticed that the bird was perched on a chainlink fence with the top border wires snipped off, forming sharp spikes jutting into the air every inch or so.
This bird simply has an irrepressible passion for spikiness.
Except for birds on and around bodies of water, and for most birds during nesting season, it's typical that the most active times for birds are early in the morning and right before dusk. Here this routine is accentuated to the extreme. Once the shrike departs, all is quiet.
From 57° F at dawn (14° C) the temperature rises to 82° F at noon (28° C) and 92° F at 2 PM (33° C). These temperatures are recorded waist high, in a sliver of shade next to the tent. Keeping the thermometer in the shade but lowering it to six inches (15 cm) above the ground, 100° F is recorded (38°C). Holding the thermometer in sunlight at waist height the mercury rises the column's full length, to 130° F (54° C).
At noon, a Pyrrhuloxia, a bird similar to a female Cardinal but wilder looking, alights for about two seconds on a yucca flower-stalk on the opposite dune, but immediately flies away not to be seen again. A couple of times four or five Mourning Doves zoom low above the dunes, as if the devil himself were after them, their wings whistling with a fast-pulsating, wheezy sound, but those incursions last only seconds. Occasionally throughout the day the Loggerhead Shrike erupts with a burry call, but it stays hidden, probably deep inside the shade of its yucca thicket. Once a few Turkey Vultures circling far over the Mesquite/ Creosote-bush zone more or less wander over the dune field's perimeter, but they never come close.
Mostly, between dawn and 2 PM, there's just the sun, the wind, the sand, and me.
A LITTLE DIZZY
At 2 PM I walk among the outrageously glaring dunes, my skin tingling in the unrelenting sunlight, the wind like dry heat from a just-opened oven door. I know I'm sweating, but the sweat evaporates so quickly that my skin stays dry. I hear myself breathing, breathing shallowly as I shuffle across the sand, but the air inside me feels artificial, like plastic air, doing its job but not the right way, and I'm a little dizzy, all the dunes crooked, not much sense of what's truly up and down.
I head for a high dune possibly half an hour away, where a small, isolated gathering of trees spotted with the binoculars lies surrounded by naked sand. There I find ten Quaking Aspens, their sparse, stiff leaves rattling in the wind but affording little shade. On one trees' smooth, white bark someone has carved his initials. Because it's so hard to focus my mind I have to count several times to be sure that it's ten trees.
For a long time I lean on the tree with initials in its bark. I feel more alone here than out among the dunes. Maybe it's because as I approached these trees I saw how isolated they were, with nothing but sand around them. I know that to the trees I looked the same, but I didn't have to see myself. I just saw these trees, and their isolation was awful.
By the time I make my way back to the tent I am anesthetized to everything, everything except the heat, and it's hotter inside the tent than outside, and outside there's no shade. Hunkering next to a knee-high Sagebrush for company, I try to keep the exposed skin on my hands and face covered with bandannas, but the wind always blows them away. I sit trying to figure out whether this strange feeling is physiological or psychological. The landscape is ommmmmmmmming again, now so loudly it's like overhead wires in a hard wind.
By the time the sun sinks low enough for a hint of coolness to return to the air, a certain oscillation inside me has harmonized with the landscape's humming and I am absolutely aloof, untouchable, like a flake of ash drifting among the dunes.
FIRST OFFICIAL BIRDLIST
Here is our Official List of birds spotted on our Official Birding Day among the dunes:
Of the species listed, only the Loggerhead Shrike gives the impression of being at home among the dunes the whole day, and for most of those hours it remains hidden, apparently deep inside yucca thickets. The Curve-billed Thrasher and Ash-throated Flycatcher must spend nights in yucca clumps, but during most of the day they remain in the Mesquite/ Creosote Bush zone. The Turkey Vultures, Mourning Doves and Pyrrhuloxia were clearly "just passing through."
Wherever sand grains are finest on the dunes' lower slopes, animal-dug pits averaging three inches across (7.6 cm) and three-quarters of an inch deep (2 cm) appear. Around these pits there are no tracks indicating what animal has been there. Obviously something flies there, digs, then flies away. But the pits are surely too large to be excavated by any insect, and I've never heard of any bird or bat digging such holes.
An hour before sunset as I wander across the lower slope of a dune where the wind hardly stirs I spot a black and white, thick-bodied wasp measuring one inch (2.5 cm) from the tip of its head, not including its short antennae, to the tip of its abdomen, and it's digging the very kind of hole just described.
"Digging" is too mild a word to describe this creature's activity. It's engaged in what seems to be a mad rush to eject from the pit as much sand as possible as quickly as possible. With its two back legs anchored far apart, again and again the insect lunges forward, thrusts its two front legs into the sand, and jerks them back so spasmodically that a nearly continual spray of sand flies from the pit, landing three inches away (8 cm). With each thrust forward the insect's head and short antenna butt into the sand. If a human worked liked this, one would say that that person is hysterical.
The wasp clutches a fly in the two middle legs bent beneath it. I think that this is a sphecid wasp, a kind of wasp that deposits its eggs near or inside animal prey. When the eggs hatch, the wasp larvae then have something to eat. I'll bet that this wasp plans to bury the fly, then lay one or more eggs next to it.
However, the wasp seems unable to get the pit the way it should be. It digs a few minutes, stops and looks around, flies away, returns, makes a loud buzz, and then it either continues work in the same pit or starts a new one. Several times this cycle is repeated; sometimes the sand ejected from a new pit landing inside a pit already mostly finished.
As darkness grows the wasp's behavior becomes even more frenetic and seemingly erratic. During a paroxysm of lunging and leg-jerking it loses grip on the fly, the fly is cast from the pit along with a spray of sand, and is quickly buried. Again the insect gives up, flies away, returns empty handed, buzzes, and starts another pit.
Finally it just stops digging and for half a minute stays frozen in the growing darkness. Then, slowly, it drags itself from the pit, and drones away. A change has occurred in its nervous system imparting to it a whole new demeanor. I'm tempted to call the new slowness a sign of the insect's having accepted defeat. This time the wasp does not return.
A grasshopper's brain can be removed, but the grasshopper will still be able to walk, jump and fly. Therefore, it's dangerous to make anthropomorphic comparisons when talking about insects. Probably it's true that insects don't think at all; they are practically little machines responding automatically to stimuli.
Yet, I feel strongly that I have just witnessed something of myself in this wasp.
Dawn was clear, except for a few clouds clustered over distant western ridges. At 10 AM white cumulus clouds materialized in the open blue sky and the wind started to stir. By mid afternoon and until around four o'clock, about a third of the sky was occupied by ragged, dark-bottomed cumulus clouds, and the wind blew briskly. Then in late afternoon the clouds thinned out, and by dusk they practically disappeared.
In other words, precisely when the day's heat was greatest, that's when clouds were thickest. Of course this happened because mid-afternoon sunshine heated up the land, hot air swirled upward in convection currents, and when this hot air cooled high in the sky, what little moisture was present condensed into clouds.
The lovely thing about this is that shadows of these clouds cool the hot ground that spawned the clouds in the first place. It's a negative-feedback situation preventing the desert from becoming even hotter than it is.
An hour or so before my second dusk among the dunes the sun plunges into a thicket of clouds heaped around the black-silhouetted ridges to the west across the vast plain of dunes and ephemeral lakes. Clouds that all afternoon have shown white with slate-colored bottoms now grow purple and take on pink linings. Here among the dunes, everything takes on sunset's strawberry-sherbet hues, especially the dust and fine sand blowing horizontally across the desert floor between the sun and me.
Most of this fast-moving dust and sand constitutes a cloud not rising over knee-high. The cloud does not move like a diffuse carpet being dragged horizontally, but rather in fast-moving waves behaving like excited snakes tangling and disentangling and rolling one over another across the dunes.
Inside this hypnotic display on the opposite dune's leeward slope a black object heavily and deliberately creeps into view. It's a tarantula. But no tarantula could be as large as this one, surely at least the size of a dinner plate. My mind still buzzing from the day's heat and glare I walk through the pink dust-snakes toward the lumbering black spot.
Up close, in the dune's wind-shadow, to my profound relief, not only is the air's agitating pinkness resolved to a more manageable grayness, but also the tarantula measures only four inches (10 cm) from tip of front hairy leg to tip of back hairy leg.
The tarantula, like my own mind, wanders aimlessly, changing directions frequently. It begins to enter a Sagebrush but ants inside the bush stream out and attach themselves to its legs. The tarantula shakes them off, backs up and goes elsewhere. I follow it across several dunes until darkness sends me to the tent.
The wind drops to hardly a breeze, the desert grows dark and somber, and chilly currents creep into the air, exactly as on the previous night. When I close my eyes to sleep, everything inside me is heat, glare, wind, blowing dust and sand, and a surreally wandering, impossibly large tarantula.
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