November 10, 2008
In both Querétaro and Chiapas Ferruginous Pygmy-Owls, GLAUCIDIUM BRASILIANUM, were common and conspicuous. Sometimes their unceasing hoo-hoo-hoo-hoo... whistle- call -- about three hoos each second -- carried on so long you sort of wished they'd stop. The species is here, too, also hooting, but not as interminably as sometimes they do. Wednesday morning along the road to Mexil one perched on a limb beside the road in plain view about 30 feet away, allowing the photo shown at http://www.backyardnature.net/n/08/081110py.jpg.
In western North America the closely related Pygmy Owl, belonging to the same genus Glaucidium, is very similar. Both owls are surprisingly aggressive for their size, are often diurnal (appear during the day) have longish tails and two black, white-outlined patches on their back necks resembling eyes when the bird is seen from behind. They differ in the Ferruginous being more reddish and having different tail barring, and in their hooting.
Easterners may not have a feeling for how small an owl should be to be considered a pygmy. The Ferruginous is about 7 inches long (18 cm), which makes it smaller than the 8.5-inch American Robin, and only a third the length of the 21-inch Great Horned Owl.
Ferruginous Pygmy-Owls are distributed from southern Texas and the US desert Southwest to Argentina.
TROPICAL KINGBIRD, MAYBE
Last Monday morning in Pisté again the cibers opened late and then my server in the US went down, so yet again I found myself wandering through town until the cyber-world got itself together. On a power line beside a dirt road I saw the flycatcher shown at http://www.backyardnature.net/n/08/081110kb.jpg.
To birders in western North America this looks a lot like their Western Kingbird. However, that species' tail is squared and has white outer tail-feathers, while this one's tail is forked and lacks the white tail-feathers. Western Kingbirds don't occur in the Yucatan.
In most of Mexico this common power-line-sitter would be quickly identifiable as the Tropical Kingbird. However, Along the Gulf Coast and here in the Yucatán there's a look-alike species, the Couch's Kingbird, of which Howell in A Guide to The Birds of Mexico and Northern Central America writes that it is "Rarely distinguishable in the field from Tropical Kingbird except by voice."
Three winters ago at San Juan Hacienda near Telchac Pueblo not far from the Gulf Coast both species were common and their calls really were different and easy to distinguish, and I never could separate the two species just by appearance. Unfortunately, the bird in Pisté wasn't saying a word last Monday.
Some authors lump the two forms under the Tropical Kingbird, so at least in that broad sense we can accurately say that in the picture is shown a Tropical Kingbird, TYRANNUS MELANCHOLICUS -- though it may be subspecies couchii.
Tropical Kingbirds are distributed from Mexico to central Argentina, but couchii occurs only from southern Texas along the Gulf Coast to northern Guatemala, including the Yucatán.
THE WHITE-EYED VIREO'S WHITE EYES
During summers in the eastern US one of the most commonly heard birds in thickets, woods margins and hedgerows is the White-eyed Vireo, not only because its disturbed, semi-weedy habitat is abundant but also because it just calls and calls TCHK iweedleiwee CHIK! over and over again. A month ago as lots of White-eyeds were arriving for the winter I frequently heard their TCHK iweedleiwee CHIK! call here but now they're quieting down. More often I hear their scolding sheh-sheh-sheh call.
Tuesday morning I heard the scolding call as I walked the road to Mexil, saw a vireo silhouette, and thought I had a Mangrove Vireo, because that species is common here year round and makes that same scolding call. However, when I snapped some pictures and got them on my computer screen, what showed up was definitely a White-eyed Vireo, as you can see yourself at http://www.backyardnature.net/n/08/081110we.jpg.
Because of the two species' similarities, on the phylogenetic Tree of Life they must be "sister species" arisen from a common ancestor. Especially when the birds' plumages are faded there's just not much visual difference between them -- except for the White-eyed's white irises. Of all vireo species -- and 21 are listed for Mexico -- only the White-eyed has white eyes, and that's only among adults.
White-eyed Vireos, VIREO GRISEUS, breed in the eastern US and northeastern Mexico, and winter from the US Southeast to northern Nicaragua.
Now during the late rainy season a certain medium sized tree here is producing such a bounty of white, three-inch broad, exotic-looking flowers that you have to stand and look awhile when you pass one. I can't find a Spanish or English name for it but it's a member of the genus Luehea, probably LUEHEA SPECIOSA. It's fairly common in hedgerows and brushy abandoned cornfields. A flowering branch is shown at http://www.backyardnature.net/n/08/081110lu.jpg.
Northerners familiar with Lindens, or Basswoods, may find it hard to believe that those large, showy blossoms are produced on a tree in the Basswood Family, the Tiliaceae. Basswoods have small flowers. However, once you think about it, the leaves in the picture are similar to those of basswoods. Also, despite the flowers' much greater size, their basic structure is similar to that of basswood flowers-- five sepals and petals, stamens many with some being reduced to sterile staminodia, and a long, slender style inside the stamen cluster. You can see a Luehea blossom, with its typical bruised-looking petals, at http://www.backyardnature.net/n/08/081110lv.jpg.
In that picture, note the flat clusters of white, hairlike staminodia curving along the corolla's bowl- shaped floor. They're very conspicuous and give the blossoms an exotic look, but who knows what they're for? Maybe they're footholds for pollinators who land inside the fragrant flowers. And who knows why it's typical for the large, white petals to have those messy-looking, bruised fringes, but that condition seems to be typical of all its flowers.
Here and there in the woods and sometimes planted around people's homes you run into a succulent-stemmed plant you've probably seen many times as a potted plant or indoor-garden ornamental. It's shown at http://www.backyardnature.net/n/08/081110mx.jpg.
Often this is called the Mexican Ponytail or Bottle Plant. It's BEAUCARNEA PLIABILIS and though it's similar to a palm it's a member of the Lily Family. You'll remember that most palm blades have either fan- shaped or featherlike blades on conspicuous stems, or petioles. Ponytails produce stiff, slender, grasslike blades arising directly from the center of the stem tip.
At its base the plant abruptly enlarges into a bulbous water-storage organ, in the picture mostly concealed by leaf litter. In plant shops often the overwatered plants on sale consist of nothing but brown, turnip- like bases from which long, green blades sprout. A Mexican Ponytail may grow for years maintaining its single slender stem but eventually if given a chance side branches develop. I've seen much-branched plants 15 feet tall and taller.
PAPAYA FRUITS AND FLOWERS
The neighbor across the road makes a halfhearted attempt to keep a garden space halfway cleared, and you'd be surprised what crops of oranges, tangerines, bananas, and papayas he harvests. One of his 15-ft- tall papaya trees bearing two immature papayas appears at http://www.backyardnature.net/n/08/081110pp.jpg.
Papaya trees, CARICA PAPAYA, are native to tropical America so maybe that explains why along roadsides and in abandoned cornfields you see wild papayas. The wild papayas' fruits aren't anywhere as large as those in the picture, though, and though birds such as orioles and woodpeckers love them, humans seldom bother to pick them. You can see some wild papaya trees at http://www.backyardnature.net/n/08/081110pq.jpg.
On the left in that composite picture you see a typical female wild papaya tree loaded with immature, eyeball-size fruits, while on the right you see a male tree's very different, diffuse inflorescence of male flowers.
The flower situation in the Papaya Family, the Caricaceae, is much more complex than the plants merely coming in boy and girl trees. Sometimes male and female unisexual flowers appear on the same plant, plus four flower-types are recognized. I don't have it all figured out myself, but at least I can show you unisexual female and unisexual male flowers taken from two wild papaya trees along the road to Mexil, at http://www.backyardnature.net/n/08/081110pr.jpg.
In that composite picture the broken-open blossom on the left is the female. The oval, green item is the ovary, the ovary's white "neck" is the style, and the five fingerlike brown things are the stigmas. Stigmas, style and ovary together constitute the female pistil. Pollen grains will germinate on the stigmas and send rootlike pollen tubes down through the style to ovules inside the ovary, where the male and female sex germs will unite. The ovules will mature into seeds and the ovary into a papaya fruit. The flattish, yellow items are separate petals.
On the right the male flower contains nothing like a pistil, plus its petals are united at their bases to form a slender tube. At the tube's throat you can make out baglike, yellow anthers splitting open to release pollen. Usually anthers are borne on slender filaments but these anthers are practically stemless, or "sessile." An anther and filament together constitute a male stamen.
At http://www.backyardnature.net/n/08/081110dd.jpg, what do you see?
A hint is that after the terrible heat of just a few weeks ago suddenly it's very pleasant, with sweater- wearing mornings, balmy afternoons and perfect nights for sleeping. Some mornings fog lies upon the land. That makes sense because the land is warm but the air cool, so toward dawn moist air next to the warm ground cools, moisture in the humid air condenses, and you get fog, and heavy dews...
So, yes, the picture shows dewdrops in sunlight, dewdrops suspended within diffuse grass panicles -- a panicle being a branched flower cluster, or inflorescence.
This is one of those pictures that can mean something to a viewer only if in real life that person has experienced what's shown. For, the picture hardly hints of the esthetic impact of the three-dimensional universe in which each droplet glistens, sometimes effervescing rainbow colors, and of course nothing in the picture suggests how alive it makes you feel walking through it all, the cold dew drenching your naked legs.
MOUNDS IN FOREST CLEARINGS
The other day far from the highway I came upon a recently cleared patch of forest in the center of which rose the eight-ft-high mound shown at http://www.backyardnature.net/n/08/081110di.jpg.
The mound was so regularly formed and so carefully nested upon a mat of freshly cut tree branches neatly contained within a circular trough of tree trunks that I couldn't imagine what valuable commodity it was. Only up close could I see that it was simple dirt. I thought a farmer must be gathering dirt to sell, for garden plots of many homes here are so eroded that there's hardly any soil at all. However, a couple of days later I came upon another mound, this one shown at http://www.backyardnature.net/n/08/081110dj.jpg.
Now I understood. Charcoal. You make a big pile of firewood, cover it with dirt, set fire to the wood, the dirt cover keeps nearly but not all air out so the fire smolders for eight days, converting the wood to charcoal instead of ashes. I'm told that a large mound produces about 100 sacks of charcoal, and each sack sells for 30 pesos (recently up from 25), or about US $2.50 at the current rate, so that's an income of about US $250 per mound.
To create this mound two or three men work for about a month, from cutting the first bush to selling the sacks. From the $250 income must come a hefty fee for transporting the bags. You can do the math to see how much money a fellow ends up with after a month, and weigh that income against the ecological damage. A picture showing the rocky-soiled clearing next to the half-finished heap in the second picture is shown at http://www.backyardnature.net/n/08/081110dk.jpg.
I'm told that usually such clearing and charcoal making precede establishing a cornfield, and that in the past sometimes charcoal making was done on a bigger scale than in the picture, so this isn't something new.
Still, I suspect that the last picture shows the future of the Yucatan's forests. As population soars and hunger for consumer goods grows even faster, in places like interior Yucatán the most easily accessible resource that can be sold for short-term profit is the forest itself. As metropolitan areas burgeon with more and more young people comeing looking for jobs -- young people from places exactly like Yokdzonot -- and because of skyrocketing energy costs, charcoal trucked from the hinterland becomes an ever-more attractive fuel.
When all of a forest is removed, organic matter is denied the soil. The soil compacts, changing from spongy and absorbent to so hard that water runs off, often so fast that it carries the soil with it. Soil low in organic matter cannot retain its most valuable nutrients, so the soil grows poorer and poorer with each clearing. In short, in terms of human lives, such clearing is permanent ecological damage.
When I try to explain this to the local people, usually they laugh and say that when the rainy season comes again everything will be as green as it ever was. Sometimes older people, who have seen the soil grow thin and poor during their own lives, agree that what I say is true, but they pose this question: What are they supposed to do? Who'll pay for their tortillas if they don't scrape for money anyway they can?
SOCIAL CONSERVATISM, TWO TAKES
More and more Maya farmers are abandoning their cornfields and I suspect that after this year's drought-killed crop the abandonment process will only accelerate. Nowadays most Maya no longer think in terms of living self sufficiently from the land; they want money more than corn, beans and squash. Most Maya prefer store-bought food, especially Cokes, white bread, crackers and the like to the humble but nutritious fare of their grandparents. Here traditional cornfields are mainly planted by socially conservative, tradition-minded older men.
In the modern world the conservative, tradition-minded impulse very often is maladaptive. That's because in the modern world wasteful and destructive behaviors have been practiced for so long that they now constitute the long-established, comfortable-feeling traditions many socially conservative folks feel compelled to conserve: Steak meals at distant restaurants; buying on impulse; deferring politically to the rich and powerful because of "trickle-down" notions.
Down here, socially conservative old men satisfy their traditionalist predispositions by planting corn, beans and squash as their ancestors did, even as their cell- phone-carrying children dismiss the whole exercise as an embarrassing waste of time.
You can see why Nature would produce a humanity in which social conservatism always arises spontaneously in any large, diverse community, just as progressive liberalism does. During the evolution of any complex community, sometimes social conservatism is appropriate and sustainable, while sometimes progressive liberalism is.
In providing humans with such big brains, Nature's idea was that we should use that brain, among other things, to decide which impulse -- conservative or liberal -- should be allowed to express itself in which circumstance.
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