GRASSLAND -
MESQUITE
October 6, 1996

Notes from a birding trip through Mexico by Jim Conrad

Grasslands & Mesquite ±100 kms north of Chihuahua, ChihuahuaDucks and geese from Canada and the United States have been settling for the winter on northern Mexico's scattered shallow lakes and stubbly grain fields. I want to see this close up.

Books describe yearly fall invasions of clouds of Mallard, Northern Pintail, Gadwall, Northern Shoveler, Green-winged and Blue-winged and Cinnamon Teal, American Widgeon, Ring-Necked Duck, Lesser Scaup, Canada Geese and more. Now I want to make my tent into an observation blind, setting it up among cattails right at the water's edge just feet from daylong duck circuses. I need some cool, moist breezes off a lake, too.

According to the map a lake called Laguna Encinillas lies along the main highway some 210 kilometers (130 miles) south of the dunes. On the day my water runs out I hike back to the road and catch a bus south.

El Lucero, Ahumada, Moctezuma, El Sueco, Arados, El Carrizalillo... The map shows the highway passing through these towns between Samalayuca and the lake. On the map the nearest town to Laguna Encinillas is Arados, so that's where I tell the bus driver I want to get off.

But the bus driver, who must have driven this stretch a thousand times, says there's no town along the highway called Arados. I say that on the left there'll be a lake called Laguna Encinillas. He knows about a lake on the left, but it's not called Laguna Encinillas, and there's no town of any size even halfway near the lake. I ask to be let off as close as possible to the lake he knows about. I've seen maps list ghost towns before, just to fill up empty spaces in desert regions.

It turns out that along the entire road the only settlement with more than one permanent-looking, occupied building is Ahumada, where we stop for a break. With a population of maybe a thousand Ahumada survives on a little ranching, some irrigated orchards, and the fact that it's the only stop for busses and trucks between Juárez and the Chihuahua City area, a total distance of 350 kilometers (220 miles). With empty desert all around, Ahumada is bustling, noisy, and self-absorbed in the manner of someone keeping obsessively busy trying to ignore their loneliness and vulnerability.

Eventually the bus driver nods to me in the mirror above his head and points with his chin off toward the east. Like quicksilver shimmering in the mid-afternoon sunlight, there's the promised lake maybe fifteen kilometers (ten miles) away, across an unbroken plain of small trees and grass, and just this side of a barren ridge rising into a meager cluster of clouds.

The driver asks if I'm sure I want to disembark in such a God-forsaken place. Hearing that this is exactly what I'm looking for, he dramatically, even theatrically, rolls the bus to a slow stop, looks at me as if I'm making a very big mistake, and opens the door.


SOFTER, FRIENDLIER AIR

This landscape here does not ommmmmmmmmm. The air is moist, soft, and friendly. Breathing it deeply is almost like drinking spring water. Feeling very good indeed I strap on my backpack, heavy with bottles of water from Ahumada, cross the road and wade into the vast mosaic of intermingling grassy openings and thickets of short trees. I am simply transfixed by every hint of moist lushness. The wind shakes large tree branches and the waist-high grass rolls in graceful waves.

In the forest areas the main woody plant is Mesquite, the same species as at Samalayuca, but here it grows much higher. Spiny acacias with short, slender spines and feathery leaves are common, and there are several species of wildflower, vine, and grass.

The grassy openings prove to be complex communities of different grass species. As I walk along I spot Blue Grama, Three-awn Grass, Lovegrass, Muhlygrass, Bluestem, and plenty of species I can't identify. No Sandbur, though, which prefers drier, sandier soil.

This pleasing diversity of grasses suggests that, despite the occasional livestock trail with its cow paddies, this vegetation is fairly natural, probably just what wandering Apaches saw hundreds of years ago. Once vast natural grasslands mantled much of northern Mexico, but now most of that is so overgrazed that the native grasses have been usurped by weeds, or else the entire landscape has been simplified to cropland. Walking through this surviving species-rich ecosystem, I feel honored.

After half an hour of hiking I catch glimpses of the silvery lake through the Mesquites' upper branches. A few minutes later the Mesquite comes to an abrupt end and a stunning view spreads before me.


PLEISTOCENE LANDSCAPE

Confounded by the scale of things, a long time I stand dumbly gawking, incapable of synthesizing what I see into a coherent understanding. Alternately looking with the naked eye and through the binoculars, normal and magnified images mingle in my mind, increasing my disorientation.

The lake looks no closer than it did half an hour ago. Between the lake and me there's an ocean of blackish green, waist-high grass, the wind making enormous, silvery waves in it, and in this grass ocean there graze hundreds, maybe thousands of cattle with magnificent, wooly-white heads and lustrous, meaty, chestnut-colored bodies, looking like Pleistocene mammoths. The whole landscape tilts crazily toward the lake. Then beyond the lake there's a wall-like ridge rising almost vertically. At the ridge's base, of all things, there's a long train so far away that the entire train fits within the binoculars' narrow field. That ridge behind the train reaches into clouds. Through the binoculars, white specks along the lake's shore are probably the ducks, herons, and seagulls I'm looking for. But in this vast grassland, spaced every two or three kilometers apart, there are men on horseback, unmoving, hunched beneath dark serapes, just sitting there absolutely still as grass waves move around them.

There's lots of money tied up in these fancy cattle, the taut-strung barbed wire encircling the whole scene, and the horsemen staying all day at their posts, so there's no place here for a wandering naturalist along the lake's shores. The whole thing unnerves me.

The tent gets pegged beneath a widely spreading mesquite about the size of a mature apple tree, and with leg-thick branches running horizontally waist high above the ground. A limb passes right over the tent, pressing down on the canvas top. Inside the tent, again and again I push the palm of my hand against the solid beam. After the phantasmal dunes, the substantial feeling of rough, unyielding wood above me is comforting.


A DREAM

I didn't dream among the dunes, but on this first night in the grassland-mesquite I have a vivid one.

I am two books hovering horizontally above the grass, bearing the library number BK 539. I see from the number that I belong in a certain section of the library but, because the number is incomplete, I don't know my exact location. I hover exhaustingly all night, expecting at any moment to receive the missing numbers, but they never come. At dawn a Coyote calls, or I dream the call, and with this wild howl it becomes perfectly clear that I am to be planted exactly here, as a grass, and the idea of being two books needing numbers is completely forgotten.


SPARROWS

immature Rufous-crowned Sparrow, Aimophila ruficeps

Sparrows, so many sparrows this morning, peeping and rustling in the leaves outside the tent. So as to not frighten them away I furtively peep through a pinhole beneath the tent-flap's zipper. Outside I see a carnival of mostly brown and gray, stubby-billed, chubby looking little sparrows, hopping about, scratching in the soil, preening, stretching, and flitting from one grass stem or sagebrush branch to another.

Mexico has about thirty-eight sparrow species and they all are variations on the themes of smallness, being gray and brown, typically having striped backs, and having bills that are short and conical, and thus well adapted for eating small grass seeds. Not a species among them bears a single feather of blue, green, or red. Male and females look the same, but juveniles have their own plumages, which are even less striking than the adults'. And around me this morning, seventy to eighty percent are young birds in various stages of drab juvenile plumage. They are this year's new crop. Identifying them will be a challenge and a pleasure.

I'm able to name two or three species immediately because of the presence of a few adult birds with distinctive fieldmarks. However, to positively identify six sparrow species it takes two days of patient watching, of reading and rereading species descriptions in my field guide, of studying habitat preferences and species ranges, and of vainly hoping that an adult male will break into its distinctive song.

For two days I drift through the tall grass and among the low, spiny mesquites and acacias, meditating on the meanings of lesser or greater degrees of brown striping on backs, lesser and greater degrees of spotting on chests, mere hints of eye rings or eye stripes, mere hints of median crown stripes, and occasional, half-hearted, fractionally articulated songs. And these two days are a joy.

You need special powers of observation to identify birds well. I look at one of these sparrows, make all the mental notes I can on breast spotting and back streaking, on whether it has an eye stripe or an eye line, or maybe a line through its crown. Once I think I've noted everything, I put down the binoculars and look in the field guide, and then I realize I hadn't seen nearly enough.

Had the bird's tail been forked, squared, or rounded? Had its lower mandible been the same color as the the top one, and had its legs been dark or pale? Nearly always by the time I realize that I must look at the bird again, already the sparrow has flown away. I feel as if all these sparrows orbiting around me in their flitting, ephemeral, seemingly unconcerned manner comprise a kind of diffuse Zen master who half teasingly, half tauntingly draws me into a frame of mind where, to glimpse the essential beauty of the thing, ever greater self-discipline is needed, ever clearer vision.

In the end, knowing that I've probably overlooked two or three species, here, in alphabetical order, are the six sparrows I identify with absolute certainty:

Now let me tell you about each of these:

BLACK-THROATED SPARROW -- photos and more info

Adults wear conspicuous black bibs below their bills, and bold, white eyebrow lines over their eyes. The species limits itself to desert scrub and has a special fondness for creosote bush. The bird's range is smaller than a lot of sparrows', only nesting as far north as southeastern Colorado, and wintering as far south as central Mexico It's absent throughout the East. The bird flies erratically and close to the ground, nervously flicking its tail, almost as if it were jittery about something. This a restrained, neat-looking, nervous little bird.

CLAY-COLORED SPARROW -- photos and more info

Particularly small, this bird has no striking feature of plumage other than a modest, pale stripe across a dark-brown head-crown. More a generalist than the scrub-loving Black-throated Sparrow, it inhabits a hodgepodge of habitats -- scrub, second-growth, edges of both deciduous and coniferous forests, burns, along rivers... Its song, which isn't being sung now, is nothing musical, rather just three to four identical, slow, low-pitched, flat, unbirdlike buzzes. Studies have shown that the pure, clear whistles of forest birds become severely distorted by strong temperature gradients and air turbulence. The Clay-colored Sparrow's low-pitched buzzes, then, is adapted for windy, open places just like this. Most North American birds are found in either the East or the West, or from coast to coast, but Clay-colored Sparrows only occupy the center of the continent. You can see its summer breeding distribution here. The species winters from southern Texas to southern Mexico.

RUFOUS-CROWNED SPARROW -- photos and more info

This is by far the most abundant species here, with more juveniles in more intermediate stages of confusing plumage than any other. It forages on the ground seldom moving high in vegetation. Often it scurries from one bush to another instead of flying. Sometimes it sings a few snippets of song, even though nesting time is far away. The song is a little musical, with many rapid notes, but the notes are weak and jumbled with no discernable structure. One feature setting it apart from the other five sparrow species is that it's the only one that doesn't migrate. I take this to mean that of all the birds here, this is the one most at home.

SONG SPARROW -- photos and more info

This bird is "family" for me. Distributed from southern Alaska to Newfoundland, south at least to southern Mexico, it was with me in my old Kentucky home. Though several generations of bird were probably involved, my mother considered the Song Sparrow claiming our backyard as the same individual year after year, and she called him Chesty. "Chesty," because when he sang he threw back his head and puffed out his boldly striped chest. My mother would always say, "Just listen to Chesty out there singing his little heart out."

VESPER SPARROW -- photos and more info

The books always speak of the Vesper Sparrow's sweet song. I've never been up North during the species' nesting season so I don't know how sweet the song is. To see if you agree with The Audubon Society Master Guide to Birding's description of the song as ". sweet, musical opening notes, usually 2 pairs of clear, unhurried, slurred notes, second pair higher pitched, followed by a descending series of rapid trills," you can hear the song here, clicking on "Listen". Not having its song to help with identification, I'm glad that Vesper Sparrows have an easy-to-see fieldmark. Their shallowly notched tails have white outer feathers that flash when the bird flies. A few other sparrow tails have white outer feathers, but those tails are rounded, not notched.

WHITE-CROWNED SPARROW -- photos and more info

White-crowned Sparrow, Zonotrichia leucophrys

This bird also has a vast range, nesting as far north as northern Alaska and northern Quebec, and wintering as far south as central Mexico. Though as a child in Kentucky I knew this bird, it was fairly uncommon and appeared there only during the winter. In the picture, notice the bold, black-and-white head striping. In  Volume 146 (1964) of Science magazine, L.R. Mewaldt reported on an experiment for which he'd captured White-crowned Sparrows in San Jose, California, marked them and flown them by aircraft to Baton Rouge, Louisiana, and Laurel, Maryland, where the birds were released. The following summer they presumably migrated to their nesting grounds, most likely in Alaska, and then the following winter they showed up once more in San Jose, California... If you know how hard it is to get a fix on one's longitude (east-west position), you'll understand how surprising this is.


HAWKS

When a hawk or falcon's silhouette mounts into the sky, alarm calls in various sparrow idioms, tense with apprehension, filter through the grass. The sparrows, typically on the ground or perched low in clumps of grass or inside short bushes, freeze and cock their heads looking upward. If the silhouette sails too close the sparrows shrink into the nearest heavy cover.

Once an American Kestrel, a falcon also known as the Sparrow Hawk, swooped in so unbelievably fast that even though it struck at something only two car-lengths from where I sat, I couldn't determine whether a kill was made. Probably I would have seen at least a feather settling to the ground if it had been.

Often I hear the loud,raspy squeal of a Harris' Hawk. With a wingspread of about 110 centimeters (forty-three inches), throughout the days of my stay, frequently it perches conspicuously on a snag about three minutes walk from the tent. This is a beautiful, unusually dark hawk, with a brownish-black body, chestnut-colored shoulders and thighs, and a black tail with a white tip. This bird keeps the sparrows on high alert.

Usually the sparrows travel in small, loose flocks. Some years ago ornithologist Thomas Caraco and his team trained a tame Harris' Hawk to fly over an area where flocks of Yellow-eyed Juncos frequently fed. Juncos are ground-feeding birds closely related to sparrows. In one experiment the junco's average flock size increased from 3.9 birds when the Harris' Hawk was absent to 7.3 when it circled over the feeding grounds. Sparrows know that there's "safety in numbers," and from the large flocks around me I'd say the sparrows here are very nervous indeed.


MONARCH ON A MESQUITE LIMB

A few days ago, on September 21, I visited my grandmother in western Kentucky. From her front yard that afternoon I saw high in the sky dozens of orange Monarch Butterflies sailing southward toward their winter grounds in the highlands of central Mexico. At dusk a few landed to spend the night in trees around Grandma's house.

At dawn on my first day in the grassland-mesquite I find a Monarch with its wings folded, daintily at rest on a Mesquite limb head-high exactly over the tent's door. It's the first of many I see sailing southward during my days here.


BIRDLIST #2

Here are the birds spotted at this stop in northern Chihuahua's Mesquite-grassland:

October 7: latitude 29º28'N, longitude 106º23'W

MEXICO: Chihuahua; ±100 kms N of Chihuahua City, on west side of lake on some maps named Laguna Encinillas; elev. ±1,500 m (±4900 feet); Mesquite averaging 3 m high, interspersed with house-lot-size natural grass meadows.

RESIDENCY STATUS:
permanent resident
transient
winter resident
  1. Turkey Vulture
  2. Cooper's Hawk
  3. Harris' Hawk
  4. Red-tailed Hawk
  5. American Kestrel
  6. Mourning Dove
  7. Northern (Red-shafted) Flicker
  8. Verdin
  9. Cactus Wren
  10. Loggerhead Shrike
  11. Wilson's Warbler
  12. Yellow-rumped (Audubon's) Warbler
  13. Green-tailed Towhee
  14. Black-throated Sparrow
  15. Clay-colored Sparrow
  16. Rufous-crowned Sparrow
  17. Song Sparrow
  18. Vesper Sparrow
  19. White-crowned Sparrow

THE VERDIN

To my mind, the list's Verdin is the "most exotic" species. Restricted to mesquite and other desert scrub, it's a tiny bird, only nine centimeters long (3.5 inches), and closely related to chickadees and titmice. Anyone knowing those birds might guess, then, that Verdins are full of nervous energy, constantly flitting from perch to perch and flying jerkily for short distances with quick, erratic wingbeats.


"RED-SHAFTED" FLICKERS

The list's "Northern (Red-shafted) Flicker" needs a comment.

When I was learning my birds in the 1960's, my Peterson Field Guide told me that in Kentucky one of our common woodpeckers was called the Yellow-shafted Flicker, and that out West there was a similar woodpecker called the Red-shafted Flicker. When our birds flew, you saw yellow in their wings, while the ones out West showed red

After my old Peterson Field Guide was published, people began considering the fact that in certain areas at mid-continent where the ranges of the two flicker species overlapped the birds freely interbred, producing fertile hybrid individuals. When a hybrid flicker flies away, instead of yellow or red flashing in its wings, it flaunts a nice salmon color.

The traditional definition of a species is that it is a group of individuals capable of interbreeding under natural conditions. Consequently, nowadays the Yellow-shafted and Red-shafted Flickers have been "lumped" into the single species  known as the Northern Flicker.

There's an almost identical story about eastern North America's  Myrtle Warblers and western North America's Audubon's Warblers, which are now "lumped" into the name Yellow-rumped Warbler, which also appears on the above list.

Notice that with both the flicker and warbler, here in northern Chihuahua I'm seeing the Western forms. As far as the birds are concerned, right now I'm more "out West" than I am "back East." These highlands can be considered an extension of the Rockies.


FALL SONGS

At dusk here in early October when there's no reason for a bird to advertise for mates or defend its territory, three species are singing, and who knows why?

They are the Rufous-crowned Sparrow, the White-crowned Sparrow, and the Cactus Wren. The sparrows' songs are rather tentative, with rapid, short, jumbled notes. To me their singing, very pleasant to hear, suggests the unfocused, self-absorbed gibberish of small children. The Cactus Wren's song is different.

Cactus Wrens are much larger than most other wrens. The familiar House Wren is about eleven centimeters long (4-¼ inches) while the Cactus Wren reaches about 16.5 centimeters (6-½ inches). To be making such a robust sound, it has to be large.

The song is low and rough, highly variable, and sometimes written in the field guides as choo-choo-choo-choo. To me the song is more like that of a car starting up on a very cold morning, grinding away but just not firing. Cactus Wrens are common and not terribly afraid of humans. Their songs are one of the most familiar sounds of the desert.


FOG

At dawn on my last day in the grassland-mesquite I am amazed when I poke my head from the tent to find a very dense fog enshrouding me. My previous mornings have been completely clear. It's dark inside this fog, and the grass is even darker with wetness. But spiderwebs, hardly noticed before, suddenly are draped everywhere, conspicuously white and sagging with shining dewdrops.

Walking through the tall grass and Mesquite, quickly my trouser legs become sodden and where they stick to my skin it's very cold. Thousands of tiny, straw-colored grass seeds stick to my legs because of the wetness. Though the air temperature is only 13º C (55º F), soon I'm shivering from the cold, wishing for the sunlight of which lately there's been almost too much.

I can see about as far as the width of a house. Beyond that there's just a pale, white glow.  My world consists of no more than one or two Mesquites and a few clumps of grass, and as I walk that small world constantly changes, materializing before me, disintegrating behind me.

The birds are so subdued, so silent and secretive, that when I catch glimpses of them they could as well be mice leaping from grass-clump to grass-clump, twig to twig.

At 10 AM, directly above, a hint of unbroken blueness comes into the grayness. A few minutes later the sun's pale orb can be distinguished. At 10:15, the fog breaks, not by becoming more and more diffuse, but by coagulating into pale curds. Vagrant breezes move into the scene and the curds are carried upwards, becoming very low clouds. The sun, already high over the eastern ridge, again becomes as brilliant and potent as ever.

The three above-mentioned dusk-singing birds break into song, and a few other species occasionally add song fragments, chips, and chirps. A Mesquite standing alone in a small prairie is absolutely bustling with small birds. Up close I see that at the tree's top about half a dozen Clay-colored Sparrows are repeatedly fluttering into the Mesquite's leaves, wetting themselves. These birds are dew-bathing!.

DEW-BATHING

Mesquite leaves are compound, looking like two green feathers joined at their bases onto a single stem. Each section of the compound leaf, or pinna, is divided into forty to fifty tiny leaflets, with the result that Mesquite leaves appear diffuse. In the present sunlight, every leaflet shows itself as adorned with a glistening dewdrop.

The Clay-colored Sparrows hop along a stem sideways until they come near a sparkling cluster of leaves, then in an instant flutter into them, land back on the stem, and more often than not shake their heads, possibly to jar dew from their nostrils or eyelids.

The dewdrop bath continues for ten minutes or so, and then Yellow-rumped Warblers arrive. It appears that the warblers have been watching and now want to join in the fun, for they land in the mesquite's crown and immediately begin excitedly flitting from spot to spot and flying about. However, they do not make contact with the wet leaves. They simply flit about the leaves and fly into the air a couple of meters or so above them. It's as if they want to share in the experience, but can't quite grasp the entire concept.

After three or four minutes, they seem to catch on.. They also begin fluttering into the leaves, dousing themselves with dewdrop spray. Have I watched one species teaching another how to take dew baths?

What a shame that in this Mesquite-grassland so many discoveries like this surely remain to be made, but I'm out of water, and have so many other places to go.

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