December 5, 2010

ROADRUNNER RERUN
Just two weeks ago we had a picture here of a speed-blurred roadrunner racing across a road. I thought I'd never get a better shot because, as I said then, "By the time you realize you're seeing a roadrunner, it's gone."

This week I was biking that part of the road south of Pisté where earlier the roadrunner had appeared. Even though I wasn't expecting to see anything I scanned the scrubby forest understory as I passed by, hoping for a better shot. Then there was movement. I stopped, got the camera ready, and after about ten minutes more movement occurred atop a roadcut down the road. Slowly I brought the camera around, auto-focused where I thought he might be, and got lucky when he stepped right into view.

You can see a Lesser Roadrunner, GEOCOCCYX VELOX, at https://www.backyardnature.net/n/10/101205rr.jpg.

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VULTURE EARS
At Pisté's municipal dump I was searching for interesting escaped plants but about the only thing going on there was the Black Vultures, hundreds of them, feeding on abandoned carcasses, butcher-shop discards, etc. The big birds were so complacent that they'd let me get within ten feet before flying. I took a picture of one just for the novelty of being able to get so close. You can see the bird's head at https://www.backyardnature.net/n/10/101205vu.jpg.

Notice the lack of feathers on the head, a condition enabling the bird to insert his head into gore and withdraw it without the mess catching beneath his feathers. Also notice the hole behind the eye. That's the ear hole.

Other birds have ear holes, too, but usually they're covered with feathers.

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A BIG GRUB
Once again Santos arrived at my door smiling saying, "I think you'd like to see this... " He'd been digging up a flowerbed and had unearthed the item shown at https://www.backyardnature.net/n/10/101205ox.jpg.

If you compare the big grub with the width of my fingers you'll see that this is a pretty big grub -- the largest I've ever seen. Volunteer insect identifier Bea in Ontario did her best on it. She wrote:

Yes, the soil Santos had been digging in was full of rotting wood. After Googling awhile and comparing lots of pictures, I decided that Bea probably was right as usual, that it was in the Rhinoceros Beetle subfamily. Moreover, of the many species in that subfamily there's one particularly common species "found in every Mexican state," whose grub pictures look just like ours.

That's the Rhinoceros Beetle, STRATEGUS ALOEUS, distributed from Arizona to Georgia and Puerto Rico south to Brazil -- just about all the Americas' hot lowlands. However, there are 31 species of Strategus beetle, so calling it the Rhinoceros Beetle is just an educated guess.

Adult Rhinoceros Beetles are so large, and the males are so impressive with their big "horns," that they're often sold in the pet trade.

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PAVON EMPEROR
I'm not expecting to see many new butterfly species these days because I was here this time last year and I would have seen them then. However, Thursday morning as I was watering flowers a species I'd not seen before -- and an exceptionally pretty one at that -- streaked out of nowhere and landed on the garden hose. You can see him drinking from the wet hose at https://www.backyardnature.net/n/10/101205pv.jpg.

Because he'd darted about so briskly, landed so abruptly, and was so thick-bodied, I thought he was a skipper, despite his antenna tips not appearing hooked as a skipper's ought to be. Maybe they hooked downward in a way that wouldn't show in the photo from above. However, Bea in Ontario wasn't fooled, pegging it immediately as a member of the enormous Brush-foot Family, the Nymphalidae. It was the Pavon Emperor, DOXOCOPA PAVON, widely distributed from northern Mexico (straying into the southernmost tip of Texas) all the way south to Bolivia. It's a member of the Emperor Subfamily, the Apaturinae, of which nine species occur in Mexico.

Pavon Emperor caterpillars feed on members of the Elm Family, of which we have at least two common, woody species here, the Iguana Hackberry and the Capulín. Adult butterflies feed on flower nectar, rotting fruit and bird droppings, all of which are easy to find here.

To me this butterfly is exceptionally pretty. Who could have guessed that the colors white, brown, powder blue, orange and rusty red might combine so handsomely?

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A YELLOW MORNING-GLORY
Next to the Hacienda's swimming pool a certain vine rankly overtops bushes below it, bearing yellow flowers, surprisingly large, teardrop-shaped fruiting capsules, and large, palmately lobed leaves, as shown at https://www.backyardnature.net/n/10/101205me.jpg.

You expect a vine like that to be one of the many species of the Morning-Glory Family coloring our landscape right now, and the flowers' basic structure confirm that it really is a morning-glory. However, those oversized fruits next to the smallish flowers (2-1/3 inches or 6 cm across), and the deeply lobed leaves don't seem right. And not many morning-glory blossoms are yellow.

The deal is that most morning-glory-type vines we run into are members of the genus Ipomoea, so we associate the traits of that genus with the whole Morning-Glory Family, the Convolvulaceae. But, what's next to the swimming pool is no Ipomoea. It's MERREMIA TUBEROSA, a whole other genus.

At https://www.backyardnature.net/n/10/101205mf.jpg you can see a side view of the vine's flower showing normal sepals. It's more interesting if you break open a blossom and see what's un-morning-glory-like inside, as at https://www.backyardnature.net/n/10/101205mg.jpg.

Actually, on the phylogenetic Tree of Life the genus Merremia lies very close to the morning-glory genus Ipomoea, so the single style arising from the ovary at the corolla base, the spherical stigmas, and stamens of unequal length all could be Ipomoea. However, notice that the anthers -- the banana-shaped, brownish items atop slender filaments -- are twisted. That's a big detail to taxonomists. Ipomoea anthers are straight, and ascending. Also Ipomoea has smaller, different kinds of fruits.

By the way, notice those "glandular hairs" at the filament bases. I don't know what their purpose is but a guess might be that where they all come together at the corolla's throat they impede nectar-seeking insects from entering the chamber below, but not the beaks of hummingbirds, who may be more efficient pollinators for this species. Below the hair-choked constriction, where the nectar is, an insect has nothing to do that would benefit the flower.

Merremia tuberosa is native to Mexico and Central America, but is grown as a garden ornamental throughout the world's tropics. It's escaped into the wild so often that it's considered a pantropical weed. Occurring so widely, it goes under many names. Some of the English ones are Woodrose, Spanish Arborvine, Hawaiian Wood-rose, Spanish Woodbine and Yellow Morning-glory.

Back in Querétaro we ran into another Merremia species, Merremia dissecta, with a showier flower with anthers much more conspicuously twisted. You might enjoy comparing our Yellow Morning-glory with that at https://www.backyardnature.net/q/alamo-vn.htm.

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KENAF THE WONDER PLANT
About 10 kms north of Pisté, on the south side of the little Maya village of Xokempiich, something came up I'd not seen elsewhere: A much-branched, herbaceous bush about ten feet tall (3 m) with stiff stems and palmately compound leaves looking a lot like those of Marihuana plants, but with large, deep-burgundy, hibiscus-type flowers. You can see the whole thing at https://www.backyardnature.net/n/10/101205kf.jpg.

A side view of a five-inch-across blossom (13 cm) is at https://www.backyardnature.net/n/10/101205kg.jpg.

A view inside the blossom showing typical hibiscus-flower anatomy -- stamens with filament bases uniting into a cylindrical staminal column surrounding the slender style, the style topped by five spreading style-branches, each tipped with a fuzzy stigma -- is at https://www.backyardnature.net/n/10/101205kh.jpg.

After pollination, the corollas fall off leaving behind ovaries which mature into nearly spherical fruits enveloped by stiff, bristly sepals, as seen at https://www.backyardnature.net/n/10/101205ki.jpg.

Most of the world knows this plant, probably native to southern Asia, as Kenaf, which is a Persian name. Among its English names are Brown Hibiscus, Hemp Hibiscus, Bimli, Ambary and Deccan Hemp. It's HIBISCUS CANNABINUS, an old Linnaeus name, so even Linnaeus thought that vegetatively it looks like Marijuana/ Cannabis. By the way, vegetatively it also looks like the Okra plant. While Kenaf isn't related to Marijuana, it turns out that Okra is indeed a close cousin. The most common Kenaf cultivar appears to be white-flowered, but other colors, such as our burgundy one, are planted.

Once again we've stumbled onto a plant I've never heard of but, once the name was known, Googling the name revealed that I'd found a famous, very important species. If you want to see a web page effusively enthusiastic about Kenaf ("Kenaf... enables the papermaker to stop using Old Growth Forest trees for paper pulp" and "Kenaf -- The Fiber That Can Change The World!") go to http://www.satglobal.com/kenaf_home.htm.

On that page you'll see that Kenaf's fiber makes good paper, rope, carpet backing and burlap. Silage made with it for livestock consumption has a high protein rating, ranging from 16 to 23%.

At http://en.wikipedia.org/wiki/Kenaf the Wikipedia page for Kenaf says that Kenaf seeds yield oil that can be used for cooking, cosmetics, biofuel and lubrication.

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WOODS-GRASS
For several weeks a certain creeping, mat-forming grass has formed an attractive, green carpet on shadowy woods floors where the gardeners have removed underbrush. Now the grass is flowering and multitudes of fuzzy grass-flower heads catch the sunlight, as at https://www.backyardnature.net/n/10/101205gr.jpg.

Closer up you can see the grasses' short but wide leaves distantly spaced on slender stems, and flowering heads consisting of six or so racemes clustered at the stems' tips, as shown at https://www.backyardnature.net/n/10/101205gs.jpg.

This is one of the most common, weedy grasses in all of tropical America as well as other of the world's tropics. It's OPLISMENUS BURMANNII. It doesn't seem to have a widely accepted English name, but other species of Oplismenus occur in North America and sometimes they're called Woods-Grasses, and our species is especially common in open woods, so that's the name I'll use here. Now at the beginning of the dry season our Woods-Grass is dropping its mature flowers and dying back, forming large brow splotches, like crabgrass up North after the first frost.

If you know grass-flower anatomy -- how the item analogous to a normal flower is called a floret, that one or more florets are gathered above a pair of glumes in a unit known as a spikelet, etc. -- you may enjoy studying this species' flowers, for grass-flower anatomy up close always surprises with its unexpected symmetries, colors, textures and forms. Before diving into the flowers you may want to review grass-flower anatomy at https://www.backyardnature.net/fl_grass.htm.

At https://www.backyardnature.net/n/10/101205gv.jpg you can see an inflorescence on which ten or so racemes arise. A raceme is a flower cluster in which a central axis bears stalked flowers -- the flowers are on "stems," or pedicels. You can see four spikelets on very short but discernable pedicels at https://www.backyardnature.net/n/10/101205gt.jpg.

Each spikelet consists of one basal sterile floret and one fertile floret. It's hard to make out these details in the picture, but that's what you'd find with a binocular microscope and a probe if you could tease the parts apart. Now look at some florets removed from their spikelets' rachilla at https://www.backyardnature.net/n/10/101205gu.jpg.

A neat feature there is how the lemmas and paleas curl down at their margins -- they're "involute." Also, they're pretty hairy. If you've studied lots of grass flowers you recognize that these florets are unusual with their fuzzy, long-awned, shoehorn-like lemmas and paleas.

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AM I IN A JUNGLE?
Visitors often arrive at the Hacienda asking what it's like "out in the jungle" or wondering whether our forest here qualifies as jungle. That's when we have to define the word "jungle."

One approach to a definition is the etymological one. The word "jungle" entered English in 1849 when British colonial agents in India needed to talk about "land overgrown by vegetation in a wild, tangled mass." For such environments they borrowed a word from the local Hindi, "jangal," which was used to describe every vegetation type from desert to forest, including wasteland and uncultivated ground. That Hindi word, in turn, had arisen from an ancient Sanskrit term applied to any "arid area sparsely grown with trees."

So, etymologically, we can call the scrubby, tangled mass of vegetation around us a jungle. It's scrubby and tangled because with our long, severe dry seasons the forest can't grow tall and lush. Since about 25 years ago this area was deforested ranchland, what we have now is drought-adapted secondary forest.

The problem with the word "jungle" was caused by Tarzan, Tarzan of the Jungle. The old Tarzan movies popularized the word "jungle," so now to the English-speaking world a "jungle" is what Tarzan swung through. And Tarzan did his swinging in forests with very tall trees with straight, columnar trunks spaced far enough apart to swing between on grapevines. By no means is that the kind of forest we have here. In most of our forest where there's no trail it's very hard and slow just to walk through without badly scratching yourself.

Therefore, since words mean what people say they mean and there are more movie goers than etymologists, then to most people we don't have jungle here. Tarzan's jungle was "tropical rainforest," and our long dry season precludes a reainforest here.

Actually, the word "jungle" has no technical basis. If you want to be accurate with what you say, just don't use the word. Often you see our vegetation zone referred to as scrub, but that term is about as imprecise as "jungle."

In fact, it's a bit tricky to say what kind of forest we do have. For one thing, we're in a transition zone between a much more arid area to our northwest, and a much more rainy area to our southeast. Another reason is that various systems exist for naming plant communities, so even the experts refer to our vegetation by different names.

Mexican governmental agencies producing vegetation maps tend to map our vegetation type as "selva mediana subperennifolia," which means "medium semi-deciduous forest," the "medium" characterizing our trees as neither especially tall nor short.

So, if I wanted to be technical, one name I could call our vegetation here is "secondary tropical medium semi-deciduous forest."

About the only forest in Mexico I've seen even approaching Tarzan-type "jungle," or true tropical rainforest, was along the Usumacinta River between Chiapas and northern Guatemala, south of Palenque, downriver from the ruins of Yaxchilán.

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MUSIC OF THE SPHERES