June 9, 2007
Last Saturday afternoon was awfully hot and I'd just finished a three-hour workshop teaching kids from a mountain village how to use computers. All that week I'd wrestled with computer code, setting up a program for the Reserve. My brain hurt and I knew exactly where I wanted to sleep that night.
I strapped on my backpack and headed to a windy point jutting into the reservoir where I pegged my tent with an open view of the sky. My tent has a netting roof so stars are visible when you lie inside. The Moon would be full that night. It made me feel better just thinking of lying in that tent late in the night, cool, crisp wind off the lake rippling my tent's walls, and that full moon lighting up my tent like a globe.
I fell asleep before nightfall came. Early in the night Pauraques awoke me calling hoarsely. The Moon still wasn't up but just edging over an eastern peak a light glimmered so brightly I had to look with my binoculars to make sure it wasn't a bonfire or a car's headlights. It was Jupiter shining with a magnitude of -2.6, my computer's astronomy program told me later. With celestial magnitudes, the smaller the number, the brighter the object. The brightest of all stars, Sirius, has a magnitude of -1.47, so with -2.6 Jupiter was really putting on a show, much brighter than any star.
The next time I awoke the Moon was right overhead. I'd slept through its rising. The wind had stopped blowing and even the Pauraques were silent. A light overcast coagulated above me and the night was turning out heavy and muggy, not crisp and cool the way I'd hoped.
Well, we're on the very eve of the rainy season here so it's supposed to be hot and muggy. Most folks say the rains are late this year, as they were last year, but Don Gonzalo says we still have a May Moon, so it can't rain.
I lay in the tent sweating, remembering how as a kid I'd read Kipling's books about life in India, and how the days leading up to the monsoonal rainy season always had been hard ones, but when the cloudburst finally came the relief was exquisite. Thinking about the coming rainy season, of hearing raindrops on my casita and tent roofs, I drifted off again, content with the night's heavy, broody feeling.
When I awoke next it was morning. Clay-colored Robins sang and somehow I felt as good as if it'd been a cool, crisp night in a windy, moony tent.
Pauraques (pow-RAH-kehs) are big, tropical, Whip-poor- will-like birds. Whip-poor-wills are often known as nightjars, and belong to the same family as high-flying nighthawks. Officially at the Reserve we have three members of the Whip-poor-will/ Nighthawk Family: The Mexican Whip-poor-will, which may be a subspecies of the Northern Whip-poor-will; the Lesser Nighthawk, and; the Pauraque. You can hear a Pauraque calling exactly as I heard them by clicking on the speaker icon at http://identify.whatbird.com/obj/858/overview/Common_Pauraque.aspx.
For years I couldn't reach the 100%-certainty threshold that I was actually seeing Pauraques. The problem was that the plumages of all nightjars are variations on the brown, mottled theme. Moreover, they all sit motionless and beautifully camouflaged on the forest floor until you almost walk upon them, and then they fly away with such unnerving fleetness that you just never get an adequate view. Did the bird's neck show a "slight cinnamon hindcollar" like the Mexican Whip- poor-will, or were the primary feathers "barred rufous basally," as with the Lesser Nighthawk?
Happily, the various nightjar species can be told by their songs, and nowadays anyone who can plug keywords into a search engine can locate audio files displaying what the various species sound like. The Pauraque has the burry p'weeEER call heard at the above link. The Mexican Whip-poor-will's call is also burry but it's phrased like pwurr-p'wiirr, plus that species stays in the pine and pine-oak highlands and we're in this hot, muggy valley. The third member of the family we have, the Lesser Nighthawk, produces a low, toad-like trill, urrrrr.
So, audio files have convinced me with 100% certainty that the birds I get fleeting glimpses of when I tramp the scrub at dawn and dusk really are Pauraques. And once again the Internet proves its value to the field naturalist.
You can see some nice shots of Pauraques at http://www.greglasley.net/pauraque.html.
MOLTING LITTLE BLUE HERONS
Though the Howell and Webb guide to Mexican birds -- the "Bible" for serious Mexican birders -- indicates that Little Blue Herons are found in Querétaro only during the winter, we have a couple of birds at the reservoir still with us, and they are something to see.
Immature Little Blue Herons are white but adults are dark, slaty-blue-gray all over. The birds I'm seeing here are in the process of changing from their white to their dark plumages, so they have a blotchy look. You can see a bird very similar to what I'm seeing now at http://www.backyardbirdcam.com/gallery/heron-little-juv.htm.
The blotchiness isn't random. The birds' outstretched wings are all white, except for a row of emerging dark primary feathers providing the outstretched wings with a well defined dark band extending from wingtip to wingtip. When the birds fly the impression at a distance is that they are white birds ornamented with a large, dark cross across their backs. I'll bet such birds have caused heart palpitations among my pious neighbors, who tend to find religious symbolism wherever they look.
I've seen such blotchy birds referred to as Calico Herons, and some people imagine that they're an entirely different species.
You have to wonder why Nature has gone to such trouble of making immature Little Blue Herons white but adults dark. I think that the consensus is that the immature birds' white plumages enables them to more readily integrate into mixed-species flocks of other white heron species, thus providing an extra measure of protection against predators.
Also, studies show that Snowy Egrets tolerate the close proximity of white Little Blue Herons more than that of dark Little Blue Herons, and that a white Little Blue Heron catches more fish in the company of white Snowy Egrets than when alone.
TURKEY VULTURES SUNBATHING ON A VERY HOT DAY
Several times I've seen Turkey Vultures with their six-ft-long wingspreads "sunbathing," and I've always figured it was for the reasons usually given in books: To dry feathers and warm the body to help digestion. However, last Saturday afternoon as I sat next to my tent gazing across the reservoir I saw three vultures sail onto the lake's opposite shore, two of them hobbled down to the water and drank for a minute or two, and then all three turned their backs to the sun, spread out their wings, and sunbathed for about 15 minutes.
Here is what made me scratch my head: As I sat there the temperature in the shade was exactly 99° (37° C). Across the lake on the sunny bank almost perpendicular to the sun's incoming rays -- if my readings made other times in similar situations can be a guide -- it was at least 115° (46° C).
The birds didn't have a morning's dew to dry off their feathers, they hadn't bathed at the water's edge, and I doubt their intestines needed more heat for better digestion.
I suspect that the advantage a vulture might enjoy sunbathing in such heat is that it might encourage some external parasites to abandon ship, or maybe die from the heat, or at least weaken so that they can more easily be dislodged by preening.
EASTERN & DESERT COTTONTAILS
Often as I jog just before dawn I see rabbits hopping about grazing in the dewy grass. As with the Pauraque, whose definite identification eluded me for years, with these rabbits I'm just never sure whether I'm seeing SYLVILAGUS FLORIDANUS, the Eastern Cottontail so common in much of eastern North America, or SYLVILAGUS AUDUBONII, the more western Desert Cottontail. We're also within the distribution area of a couple of jackrabbit species, but those are such long-eared, rangy-looking and usually easily spooked species that I know I'm seeing them during my morning jogs.
In western Kansas the two cottontail species similarly overlap in distribution. A University of Kansas webpage says that "The desert cottontail is difficult to distinguish externally from the eastern cottontail, but is paler, and has longer and more thinly haired ears. Its upperparts are pale grayish brown heavily lined with black and with some yellow."
It continues, "Desert cottontails are usually found in dry, open upland habitats, whereas eastern cottontails in the same areas of western Kansas are restricted to riparian thickets along streams."
I suspect that that's also the case here -- that out in the scrub we have Desert Cottontails, but down in the lush vegetation along streams in valley floors we have Eastern Cottontails.
But, who are these black silhouettes I see in the mornings when I jog in this valley beside a manmade reservoir surrounded by scrubby slopes?
You can see if you detect obvious differences between the species. A good picture of an Eastern Cottontail is at http://www.duke.edu/~jspippen/mammals/mammals.htm.
A good picture of a Desert Cottontail is at http://wc.pima.edu/~bfiero/tucsonecology/animals/mamm_deco.htm.
In biology, adventitious things are those which are "of or belonging to a structure that develops in an unusual place." Thus adventitious roots are those appearing in places where roots usually don't occur. English Ivy's stem-arising roots are adventitious, and when a blackberry cane bends over and roots where its stem touches the ground, those roots are adventitious.
So, down at the far end of the reservoir where the valley is narrow and the sheltered vegetation lush, many of the trees are hosts to woody vines. And of course anything more or less woody that can be hacked with a machete eventually will be hacked, so most vines end up as dead, severed stems dangling from branches overhead.
Some woody vine stems put up a fight, however. Right above the point where they're cut, adventitious roots may appear and many eventually reach the ground, enabling the vines to survive.
The other day I found two such a severed vine stems dangling together, with their many slender adventitious roots artfully treated as shown at http://www.backyardnature.net/n/07/070609ra.jpg.
Surely a kid had expertly braided the roots, and I like to think that the impulse behind the braiding may have arisen from deep roots. I've seen similarly braided pigtails gracing the heads of many traditional native-American women in Mexico.
Not 30 feet from the braided vine roots stood what's to see at http://www.backyardnature.net/n/07/070609rb.jpg.
The massive, dead trunks I think are the remnants of Montezuma Cypresses killed by the reservoir's waters. Atop the trunk at the right, a Bonpland Willow has become established and grown into a regular-size tree. About half of the year the water level here reaches where the willow's mass of roots blouse out, forming a sort of island where other woody plants also are taking root.
What a struggle life makes to preserve itself, and down at the end of the reservoir, last Saturday, it was roots who told me all about it.
OLD STONE FENCES ON THE VERGE OF THE RAINY SEASON
Wandering across the scrubby slopes above the reservoir often you run into the remains of stone fences whose antiquity you can hardly imagine. You can see one at http://www.backyardnature.net/n/07/070609sw.jpg.
The walls remind me that -- much in contrast to much of Mexico's mountainous regions -- in our area many slopes are reverting to forest after being converted to fields or livestock-producing ranches years ago. We are so isolated by surrounding mountains that industry hasn't taken hold here, so many people have abandoned the land to go live in larger cities or work in the US. In the overpopulated southern states most mountain slopes have been deforested and are eroding at an appalling rate. Here people talk about how now the slopes are green where once they were laid bare.
In the above picture, notice the springy feeling the vegetation conveys, in terms of half-expanded leaves. Up north, such a picture would indicate that fleeting moment in spring when Nature has decided that probably the last hard frost has passed, so issuing leaves now would be a good bet. It's a similar dynamic here, the bet being that rains will come so soon that the just- emerged leaves will be able to keep expanding.
MEXICAN FRITILLARY IN THE FROGFRUIT
I've told you about the flowering frogfruit mantling the former mudflats that now are high and dry, and inhabited by countless tiny frogs. The frogfruit flats continue being the very best place to see lots of butterflies. This week I was trying to sneak up on a rarely appearing species so I could photograph it. It flew away, but another pretty species flitted right into focus, so I'll introduce you to him instead.
He was a Mexican Fritillary, EUPTOIETA HEGESIA, one of the many Brush-footed Butterflies of the Nymphalidae, and you can see his pretty orange-and-black pattern at http://www.backyardnature.net/n/07/070609mf.jpg.
You can confirm my identification by matching pictures, see what the species' chrysalis looks like, note how far the species extends into the US, and read about its behavior and foods at the wonderful, newly reconstituted Butterflies & Moths of North America site at http://www.butterfliesandmoths.org/species?l=1673.
On that page note that the first two foods listed for adult Mexican Fritillaries are Lantana and Stachytarpheta. Both of those genera are members of the Verbena Family, which agrees very nicely with my finding them so abundantly in the frogfruit, which belongs to the genus Phyla, an honored member of the Verbena Family.
On Wednesday with Julio and Pancho I took off for high- elevation La Trinidad, about three hours to the east in the state of San Luis Potosí, my plan being to instruct potential nature-guides on the guiding art. Taking a very steep, broken up, one-lane road up from Xilitla, about halfway up the slope we came before a heavy rope stretched across the road. The short story is that that community was feuding over water and other things with another community upslope, so this lower community had decided to stop traffic on the only road serving the upslope community. "They cut off our water, so we cut their road." We turned around and headed back to Jalpan.
On our way up we'd equipped ourselves quite nicely for eating at La Trinidad, knowing that the folks up there, despite their genuine hospitality, just don't have much to share. Therefore, we decided to find a shady spot along the road and have a picnic! Pancho's wife had prepared us a wonderful dish for the next day, consisting mostly of beans, tomatoes and hot peppers, and we weren't about to return with such a delicacy uneaten.
There on the eastern slope of the Eastern Sierra Madres the rainy season already had begun, though not with its usual vigor. Vegetation was rank and the landscape was as green as Ireland, all so very different from the dried-crisp scrub in the valley back at Jalpan. From our picnic spot we had a view toward the Gulf lowlands in the east, but the lowlands were hidden by cottony clouds and slowly swirling haze, clearly building toward an afternoon storm.
Right beside our picnic spot stood a tree fern with individual fronds up to 12 feet long. You can see Pancho standing below it at http://www.backyardnature.net/n/07/070609tf.jpg.
The fern is LOPHOSORIA QUADRIPINNATA, distributed from Mexico and the West Indies south to Brazil. Despite its exotic look, it's sort of a "weed tree," being among those tree-sized plants that invade disturbed areas such as fields while the vegetation cover "succeeds" through one stage after another, until stable forest returns.
One implication of this being a "real fern" is that it reproduces by spores instead of flowers and fruits. Tree ferns reached their peak of diversification during the Carboniferous Period 354-290 million years ago. Later they lost ground to species benefiting from the later-day inventions of flowers, fruits and seeds. In a sense, Lophosoria quadripinnata is a living fossil, somehow surviving despite its outdated technology.
In the dense, moist shade just beyond the tree fern and its lush wall of plants I spotted something red glowing in a ray of sunlight, went to investigate, and found a Lobster Claw, sometime also called Parrot's Beak and Fire and Ice. It was a very pretty member of the Banana Family, HELICONIA SCHIEDEANA, and you can see it at http://www.backyardnature.net/n/07/070609hc.jpg.
As its raggedy leaf in the background indicates, this was an old plant. The red, snaky items are bracts, or modified leaves, helping draw pollinators' attention to the flowers of this plant, which often grow in deep forest shade. This plant's yellow flowers had been pollinated and subsequently dried up long ago -- you can see the blossoms' shriveled, brown remains still nested atop the red bracts. The spherical, stalked items are maturing fruits.
Though Lobster Claw is a native Mexican plant the species is planted in gardens worldwide. It's regarded as relatively easy to grow and can stand a little frost, which sounds about right for a plant occupying a high-elevation secondary forest like the one we were picnicking beside.
Noticing the plant's broad, glossy leaf in the background, it's easy to believe that Lobster Claw is a member of the Banana Family. One feature distinguishing banana plants from heliconias is that leaves and bracts are spirally arranged on banana plants (visualize bananas clustered all around the central fruit-stalk) while in heliconias leaves and bracts alternate from one side of the stem to the other (they're "distichous"), often zigzagging. Also, banana fruits don't split open when ripe (they're indehiscent) while heliconia's three-seeded fruits do split open (dehisce) at maturity.
SIERRA GORDA ON THE BBC
A reporter from the BBC came through the other day, the result being a very positive and encouraging slide show and commentary about Sierra Gorda Reserve on the BBC's website. So far I can't find the piece in English. Still, you might enjoy seeing our landscape and people through the eyes of the BBC reporter. Click here.
ECOLOGY OF A ROPE ACROSS THE ROAD
In the above stone-fence section I pointed out that the area around Jalpan is so isolated that little industry has taken hold here. Mountain slopes, on the average, are actually revegetating as people abandon cornfields and ranchos to go live in cities or work in the US. When you cross the Eastern Sierra Madres as we did Wednesday and start descending toward Xilitla, not only does the vegetation suddenly become much lusher and the climate rainier, but also population density skyrockets and mountain slopes start looking very sad as farmers put more and more cornfields on steeper and steeper slopes, on thinner and thinner, fast-eroding soil. We were in that environment across the Sierra when we encountered the man with his scowling face and rope across the road.
Overpopulation results in usually-friendly, hard- working, well-meaning people being pitted against one another in competition for limited natural resources. History and current events show that the ecological causes of such conflicts (not enough natural resources for everyone) usually become irrelevant or even forgotten as mutual hatred and fear is stirred up by those achieve leadership positions fulminating against the neighboring "evil doers," the "infidels," the "terrorists." Then the violence comes as a consequence of hurt pride, of patriotism or religious fervor, or of blind reaction to fear.
If in a disciplined manner we keep focused on the ecological roots of such conflicts, the solutions to avoiding them become obvious:
- Population control
- Equitable distribution of resources
- Good planning
These are the techniques used by Nature to keep Her own house in order. Population control is managed with starvation, disease and conflict. Functionally equitable distribution of resources is assured through "survival of the fittest," with the less fit going extinct and the survivors being left hustling fulltime for resources. And one could say that nothing is better "planned" than Nature with all Her interconnected, interdependent parts.
The wonderful thing about humans, then, is that we have big brains with which we're able to figure out such problems as how to control our numbers without depending on the more traditional agencies of starvation, disease and conflict. We're able to plan things down to the tiniest detail. And we can be smart enough to know when to stop perpetually rushing about doing busywork, pause, and think a bit about what we're doing, and... WHY!
Poor man with his rope across the road. He wasn't even personally responsible for his mountain slope's problems. The troublemakers had been those before him who, as their valley filled with homes, their forests disappeared and their soil grew thinner, just kept piously and politically correctly doing what they'd always done.
Maybe the scowling man with his rope would make a good icon for the current fight against global warming.
Best wishes to all Newsletter subscribers,
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