Notes from a birding trip through Mexico by Jim Conrad
From Santa Catarina I had planned to continue eastward and downward into the steamy, profoundly lush, loud, odoriferous and overpopulated Gulf Lowlands. However, back at Santa Catarina I find myself dreading leaving the peaceful higher elevations. Against all plans I take a bus heading back westward, upslope and over the Sierra de Alvarez, all the way back to the city of San Luis Potosí, where at midnight I enter another bus bound south to Toluca, just to the west and across a mountain from Mexico City.
Dawn's first light finds our bus entering Toluca, population about 400,000. From the steamed-over window I can't take my eyes off the graceful cone of Nevado de Toluca Volcano gorgeously looming above town to the south, as pink and inviting in the morning sunlight as strawberry sherbet. Though Toluca lies in a broad valley, it's still in the highlands at an elevation of 2,679 meters (8,790 feet). That's more than a third higher than Denver. Exiting the bus, a raw chill cuts the air and I wonder what it's like up there on the volcano. However it is, it's surely the opposite of "steamy, profoundly lush, loud, odoriferous and overpopulated."
Streets around Toluca's Friday market day already just an hour after dawn are clogged with carts of bananas, mahogany-colored heaps of Metepec pottery, kiosks selling greasy pig-cracklings... It's all a feast for the eyes, and despite my misanthropic mood it's good to be shoulder-to-shoulder with such a soup of good-natured, self-absorbed humanity making the best of hard times. I'll be on the volcano in a while, so I stuff my backpack and two more shoulder-strap bags with food and cartons of milk.
A bit before noon a local bus deposits me at the head of the gravel road leading into Nevado de Toluca National Park, up through pines to the volcano. It's about eighteen kilometers to the top (eleven miles). The slope is steep and the air thin, but the fresh odor of pine, the solitude and the pleasing cadence of hiking please the soul.
In late afternoon with the cloud ceiling churning and dropping rapidly, and ominous thunder building, I reach the treeline. Now the landscape becomes one of boulders and steep, grassy slopes, all scoured by a truculent wind. Another twenty minutes puts me at a stone hut not far from a little ranger station. Exactly at this moment a vast wall of murky fog envelops the whole slope, the wind twists itself into a rage, and a torrent of rain and icy slush begins falling.
I'd planned to camp inside the crater tonight, but now I gladly pay the ranger for a bunk in the hut. By the time I make it to the hut it's more snowing than raining, the ground is white, the wind screams around the hut's corners, and the fog is so dense you can't see a house-length away. The ranger says we're at 4,050 meters (13,287 feet). The temperature lies exactly at the freezing point.
The hut, built of local rock, is provided with tiny windows barely admitting a dim western light. It contains about a dozen double-decker cots and smells of ice and mud. There is no electricity and no other lodgers. I'm so cold and tired, and it's already so dark, that at 5 PM I prepare for sleep.
I have not mentioned that I am traveling without a sleeping bag. I wanted to travel light, and to test an alternative manner of keeping warm. As I did during the freezes at Lake Arareko, now I don seven shirts, three trousers, four pairs of socks, gloves, scarf, and a wooly cap, and wrap myself in my single light blanket.
Nevado de Toluca Volcano, known as Xinantécatl to the Nahuatl-speakers whose homeland this once was, peaks at 4,577 meters (15,016 feet), a good bit higher than both California's Mt. Whitney and Switzerland's Matterhorn, but only fourth in height among Mexico's peaks. At dawn the temperature has risen to 3.3º C (38º F) and I have slept the night comfortably. The sky is clear. The slope above the hut is white with fresh snow. In the sunlight-gathering wind-shadow of a boulder on the eastern slope, for a long time I hunker warming as a terrific gale howls all around.
Volcanic rock cliffs soar above and dark gray talus slopes, broad essays in jumbled angularity, fan all around me. Below, slopes are mantled with ankle-high bunchgrass gesticulating wildly in the wind. The most conspicuous wildflowers are the widely spaced and extremely tough, spiny, thistlelike plants called Eryngium in Latin. Black basaltic rocks of all sizes, splotched with yellow-green moss, emerge from the ground everywhere. The glaring, high-elevation sunlight stings my face and warms the eastern side of my body, but my shadowed western part remains icy. The binoculars show, down below the tree line, perfectly black silhouettes of widely spaced pines in pea-green meadows.
As soon as I'm warm enough to move I'm upslope and across the crater's rim into the grassland inside the crater. It's hard birdwatching here with the binoculars jiggling in the wind and the lenses steaming up, everything optically compressed into a flat jumble of gray, green and black forms. I do spot a retiring flicker of paleness vanishing behind a boulder in a field of knee-high boulders, but it could have as well been a mammal as a bird. Eventually I make out a few roundish forms in the grass and gradually some of the pale smears coalesce into brownish streaked breasts camouflaged as frost-killed grass and finally I make out legs and beaks and eyes. Now I behold about thirty American Pipits, their long tails weathervaned downwind. Once they're convinced I'm harmless they begin walking low and fast against the wind -- walking, not hopping -- as pipits do. They don't trust me completely, though. There's always one or two atop boulders near the flock and if I creep too close they give a one-note call and the flock flurries farther away.
American Pipits nest in the Arctic tundra and high mountains, so being here right now they are indulging their passion for cold, windy, wet places, and it pleases me to find them so fulfilled. The last pipit I saw was on a January afternoon, next to a sleepy pond on the University of Florida campus at Gainsville, and I felt sorry for it. Not all pipits can find high, grassy volcano craters in which to overwinter.
Conspicuously perching atop boulders along the trail leading from the crater on the northern slope there's a species even more exquisitely wedded to these high-elevation cold winds, low grass and rocks, for they spend their entire year here, not migrating north or south. They are endemic to the Mexican mountains from Chihuahua south to Oaxaca and my field guide says that they occur only in grassy openings, meadows and pine forests between 1500 and 4200 meters (5000-14,000 feet). Here we're a bit higher than 4200 meters. It's the Striped Sparrow.
It's always a special pleasure to meet organisms whose adaptations are so refined that their species' distribution and habitat requirements are very narrowly defined. It's like finding a geode with perfectly formed and preserved crystals inside: One senses the enormity of time needed for the step-by-step unfolding of such an exquisitely particular thing.
If one wishes to hear the landscape speaking, then surely nothing articulates more eloquently and beautifully than a lifeform evolved to exist exactly there and no place else.
In the afternoon three black bird-forms come to play in the wind surging through breaks in the volcano's high rim. They don't seem to be searching for food. They just spend an hour zooming toward cliff faces, banking at the last moment, and stalling with cupped wings where mighty blasts of upward streaming wind rises beneath them. What could these Common Ravens be doing but playing with the wind?
I know they're ravens and not some kind of crow because of their size and their silhouettes. In the sketch, notice how the tail of the larger raven on the left is "wedge shaped," not squared or broadly rounded like a crow's. Ravens "croak" while crows "caw," though sometimes immature crows also "croak." At this distance, the tail is the thing.
Opposite to the Striped Sparrow, few birds are more widespread and flexible in behavior than ravens. Found throughout the New World and the Old, in both hemispheres, they eat an amazing variety of things but seem to prefer insects. They also eat small mammals, birds, eggs, scorpions, amphibians, and lizards, as well as many kinds of plant material.
In a boulder field with wind forming fast-moving waves through the clumpgrass a sharp chirp pierces the air. Several Striped Sparrows until now invisible explode from the grass like a shattering bubble and scatter in all directions, flying low and hard. Half a second later, its wings held straight out like a model airplane, a Sharp-shinned Hawk comes flying low and very fast, a blurred image stabbing through empty space where the bubble had been. The little hawk, its wingspread only 53 centimeters (21 inches), zigzags so violently that the eye can't follow it, and if there's been a kill it was invisible to my eyes. Then the hawk arches over the slope and all is silent.
The whole thing ends before it's understood what's going on.
What an elegant manner of killing, and of dying.
Hawks are thick up here. Tunnels and earthen mounds among the boulder fields and along talus-slope edges show that many mammals live here. It's surprising how many lizards and grasshoppers loll on sunlit rocks. There are no trees or bushes to hide under, so all these creatures must make attractive targets for sky-high predators.
One hawk dives at something but misses, and this hawk is unlike any portrayed in the field guides. With broad, rounded wings and a stocky body, it's obviously one of that group of hawks birders call buteos, but it's completely black.
Cold, wet wind hisses through the boulders, thundering in the ears, burning cheeks, numbing the hands and stiffening the binoculars' focusing wheel. The sky is evenly dark blue and the high-elevation sun fairly screams its bright glare. Wind lashing all around causes the black bird's binocular image to jiggle and then suddenly the black-hawk mystery is solved when the bird draws near the sun: With sunlight filtering through it, the black silhouette's tail glows a rusty red.
Of course, it's just an old friend in a different guise, a black form of the Red-tailed Hawk.
Nature is doing something interesting here. It's playing with the facts that black objects and black organisms absorb more sunlight energy than lighter colored ones, and that organisms at high elevations need all the help they can get staying warm. It's "melanism" -- an instance of an animal being black or nearly black, when most of the members of its species are otherwise. Except for their rusty tails, most Red-tailed Hawks are brown and white. This high-elevation "melanistic" form, however, was born black, and its offspring will be black.
Here is the Official List for above the tree line:
MEXICO: Mexico State; Nevado de Toluca Volcano ±16 air-kms south of Toluca; elev. ±4,250 m (±13,900 ft); above treeline
In the afternoon storm clouds boil over the western ridge threatening to wash back and upward to engulf my slope so I hike back toward the hut. Arriving there with sleet bouncing off my shoulders and certain gusts of wind almost knocking me to the ground I open the hut's heavy wooden door to find a companion for the night, a young man named Horacio. He's ridden here on his mountain bike along off-road trails from Toluca. Handsome and muscular, he sits at the hut's wobbly wooden table writing a children's story by candlelight. Instantly we're friends, and we talk into the night.
Next morning I take off for the crater again but see nothing I hadn't seen the day before. This time I spend more time sightseeing. From Nevado's northern slope the view into the broad valley below is majestic. Through binoculars nearly every major building and street in Toluca can be recognized. At midday I return to the hut to find Horacio gazing into the valley. He draws my attention to the fact that from horizon to horizon the sky is clear, except exactly over Toluca.
There, floating like an enormous mushroom with a bulbous cap, a dazzlingly white, billowing cumulus cloud casts its shadow onto the city below. Horacio says he's been watching the cloud grow from a single wisp, and that during other visits he's seen something curious many times: Hot air from Toluca's pavement and buildings rise into the sky, cools, and as the moisture in this air condenses, substantial clouds like this one form.
"For the rest of the day, keep an eye on this cloud," Horacio suggests. "Sometimes the very same cloud stays visible until dusk."
A couple of hours later the cloud has drifted toward the northwest and it's developed a rounded thunderhead towering so high that it spreads into a broad anvil shape. Above Toluca, a second cloud has formed just like the first.
By dusk the sky all around has grown moody with dark-bottomed clouds, but we can still pick out our midday cloud, now grown into a massive purple bank, an immense thunderhead looming over smaller storms all around it. It's too far away to guess at its distance. Between this first cloud and Toluca now there rise four big clouds just like the first, all in a row and all formed over Toluca.
At nightfall an impressive display of lightning takes place beneath our distant cloud, though it's too far away to hear the thunder. Surely by now this storm is in the next state, in Querétaro or Guanajuato.
I have never seen such a plain example of humanity altering the weather.
After a couple of days above the treeline and after Horacio leaves I pack up and head below the tree line. The transition between windswept grassland and forest takes place in less than the length of a house. On Nevado's sun-bathed southern slope the treeline resides at about 4,020 meters (13,200 feet) but on the northern slope it dips to about 3,850 meters (12,600 feet).
Inside the forest the sunlight filtering among widely spaced pines yellows and softens. The always-buffeting wind calms, and instead of screaming or roaring now it sighs among the pines' boughs. There's the gladdening odor of pine resin warmed by sunlight and the air is perceptibly moister, feeling good on chapped lips and skin. A surprising community of flies and other insects lazily buzz around, and spiderling gossamers streak the air. In a matter of just a few feet I have simply walked from one world into another.
Earlier something inside me needed the wild, lonely crags above. Now I've had enough of that, and dipping below the treeline is just what I need..
The tent is pegged on an ankle-deep mat of cushiony, greenish-straw-colored clumpgrass among pines at an elevation of about 3,800 meters (12,500 feet). The pines are Pinus hartwegii, sometimes known as Timberline Montezuma Pines. They are so widely spaced that about two-thirds of the ground at any one time remains bathed in sunlight.
The trees rise to about fifteen meters (fifty feet), and have a unique look to them. Two-thirds to five-sixths of a trunk's total length, the part below the crown, is either limbless or else bristles with old, broken-off tree limbs. Needles appear only in dense clumps at the ends of branches.
The clumps of needles at the trees' tops are so compact and hard to penetrate that birds tend to use them as high-perched thickets in which to take shelter. Hawks are unlikely to attack them there. As I'm approaching one tree a bird inside its high-perched thicket grows nervous and tries to fly away. However, the close-packed needles and branchlets hem in the bird so closely that its wings tangle, the bird loses its cool and starts flapping uselessly, causing dislodged tree-bark and patches of lichen to tumble from the platform. This goes on for ten seconds before finally the bird works its way to the pine-needle-thicket's perimeter. First its head pokes out and then its wings. Then, as if the Devil were after it, it flies to another tree-top thicket farther away.
The bird is an American Robin. There's a whole, nervous-acting flock of them dispersed among the pine crowns around me, looking at me with the greatest distrust showing in their body language. These wild, very nervous creatures certainly seem to have no connection to the easy-going earthworm-pullers in suburban lawns up north during summers. American Robins breed in Mexico's highlands so I just don't know whether these birds are permanent residents on this volcano or if they're wintering from farther north.
At night the pines continue expressing themselves. These nights there's a full moon all night so being in the tent is like being inside a glowing Chinese lantern. Black shadows of gnarly branches and tufts of needles move across the tent's roof from dusk to dawn. I awaken many times, each time the shadows a little farther along. Sometimes breezes sigh among the pines. Sometimes the breezes dislodge dried-up clusters of pine needles and they fall onto the tent's stretched-tight roof making friendly plunks that don't even frighten the mouse rustling in the grass outside my door.
We have mixed-species flocks here, too. Here they seem to comprise fewer species than the ones we've noted elsewhere, but their flurries of activity are just as striking.
One flock is composed of a fussy nucleus of eight to ten Mexican Chickadees, with five to eight American Robins more loosely gathered around. When the bubble drifts over a car-size bush a single Orange-crowned Warbler flits atop the bush, forages while other birds orbit around it, but when the flock wanders too far away, the warbler withdraws back into its bush.
Another flock has at its nucleus five Mexican Chickadees, one White-breasted Nuthatch and one Olive Warbler. More loosely associated are one Brown Creeper and one Hairy Woodpecker.
At the stroke of dawn, right beyond the tent's flap, there's a brown, cold-killed thistle hoary with frost. The sun rising above the ridge behind the plant casts its blazing light in extended, slanting rays past pine trunks, onto the ground, the tent, and my face. The frosty thistle makes a satiny silhouette outlined in fiery fleece, and because the wind begins to stir, now the thistle dances.
Though the air temperature lies at the freezing point, a spiderling at the tip of one of the thistle's top spiny leaves, at the very moment I look from the tent, releases a spray of silk into the air, and this spray of silk absolutely detonates with radiant sunlight.
Then, in an instant, my elbow slips or my mind does something queer or a pine someplace leans into the sunlight, shadowing the spectacle, and the whole magical vision vanishes. When I go look atop the thistle there's no spiderling to see.
On sunny October afternoons in the north, the blue sky is often streaked with sunlight-catching gossamers. Gossamers are lengths of spider silk carried by the wind, and attached to the gossamers' bottoms are tiny spiderlings. This manner of young spiders traveling on the wind with gossamers is called ballooning.
Here is the Official List for below the tree line:
MEXICO: Mexico State; Nevado de Toluca Volcano ±16 air-kms south of Toluca; elev. ±3,800 m (±12,500 feet); not far below the treeline
The above list's Red Warbler deserves a remark. Northern birders know that warblers are simply not red. American warblers are typically combinations of yellow, black and white, but the Red Warbler's entire body is very red, except for white cheek-patches, which only accentuate the red. This bird is red red. The species is even more special because it's endemic only to the pine forests of Mexico's high mountains, not even making it across the Isthmus of Tehuantepec into Chiapas.