JIM CONRAD'S
NATURALIST NEWSLETTER
Issued in the northern Yucatán,
MÉXICO
January 12, 2009
| AT AN UNDISCLOSED LOCATION Moments after issuing last Monday's Newsletter I jumped into a car and hitched a ride 20 kms south of Mayan Beach Garden Inn, to the Mahahual bus station. That night I bused from Chetumal across the Yucatan Peninsula to Mérida, then Tuesday morning bused to... I'm not saying because the property owner where I am is a private person who prefers to not receive unannounced visitors coming to see me. Here it's not a matter of just walking up to a door and knocking. My stay at Mayan Beach Garden was excellent and I leave behind wonderful friends. The hotel was so isolated, though, that unlike nearly all the rest of Mexico there was no public transportation, not even regularly running pickup trucks. My wandering and food-buying activities were very limited. A month there hiking up the same road every day and back along the same beach was perfect. But, now to something different: ***** LOCUST SKY-RIVER Locusts, millions and millions of them streaming southwestward in a vast, sinuous, constantly form- changing sky-river, causing a deep ommmmmmmmmm in the sky, absolutely breathtaking. The picture doesn't capture the power in their irrepressible movement but at least it hints at the numbers. I ran onto my hut's flat concrete roof and saw that the river stretched from horizon to horizon, that it parted and merged here and there, and it twisted and bent like an endless, squirming snake. At first it seemed that no locusts were on the ground around me but then I passed beneath a palm and thousands exploded from the fronds above me and swirled upward to join their brethren in the sky. Most trees here are leafless now because of the dry season but suddenly I realized that tree branches were heavy with untold numbers of silent, unmoving locusts, shown at http://www.backyardnature.net/n/09/090112l2.jpg. I wanted to photograph an individual locust, which looks like a normal grasshopper, but unlike during other outbreaks I've experienced Sunday's insects were jumpy and wouldn't let me come near. It was very hot and windy so maybe the heat gave them extra energy or set their nerves on edge. I never did get a good picture of a single individual, for every one of them was in a high state of alert, and simply flew off as I drew close. For those of you needing an ID, the shot at http://www.backyardnature.net/n/09/090112l3.jpg may help a little. The vast sky-river of locusts passed overhead for about 45 minutes, but who knows how long they'd been passing before I saw them? ***** GREAT HORNED OWL WELCOME I've been wanting to test my digital camera in very limited lighting so this was a good time for that. Hardly able to see the ground I worked my way toward the hooting until the big owl's silhouette appeared against the fast-lighting sky. It was about 20 feet up and 40 feet away on a crossbeam projecting from the side of a very tall stone chimney next to an old hurricane-collapsed henequen mill. You can see the results of this low-light picture-taking experiment at http://www.backyardnature.net/n/09/090112ho.jpg. When I first downloaded the above picture into my computer it showed up as nearly solid black. However, with PhotoShop I coaxed the owl's very grainy, colorless but early-dawn-evoking image into existence, reconfirming my general suspicion that most good photos are less the results of artful camera use than artful use of a darkroom or a good image program. The property owner tells me that Great Horned Owls have nested at this same spot for many years producing generation after generation of young. An adjoining plot of scrub forest was purchased largely with the intent of providing a secure hunting ground for them. ***** A CLAY-COLORED ROBIN'S MEW Clay-colored Robins have the same shape and size of American Robins, which belong to the same genus, Turdus, and they share many behavioral features with them, but they lack the American Robin's reddish- orange breast. Since the Clay-colored's distribution begins more or less where the American's ends, you can think of the Clay-colored as being the tropical version of whatever the American Robin is the temperate-zone version of. Clay-colored Robins are distributed from the Mexican Gulf Coast just south of Texas to northern Colombia. ***** SISTER BUTTERFLIES Bea says that that's a Massilia Sister, ADELPHA PARAENA MASSILIA. I'm particularly glad to have that identification because I've seen butterflies very like this in many places -- brown butterflies with bold white bars forming Vs across their backs, and with orange patches near their wingtips. As the butterflies perch they tend to open and close their wings, maybe causing a predator to think in terms of a dangerous mouth opening and closing. I first remember seeing a look-alike species back in California's Sierra Madres when I visited my friend Fred in 2005. That one I identified as the California Sister, Adelpha bredowii. Notice that it belonged to the same genus, Adelpha. Dozens of California Sisters were seen during a June hike up Slate Mountain. The field guide said the species' caterpillars ate leaves of the area's Canyon Live Oaks. Too bad I didn't have a camera then, for in my memory California Sisters looked exactly like the above-pictured Massilia Sister. Last year I did have a camera when one day yet another very similar butterfly landed on a wet washrag outside my cabin ruin in the cold oak-pine-sweetgum forest in upland Chiapas at Yerba Buena, as you can see at http://www.backyardnature.net/chiapas/butt-024.jpg. My friends at the Mariposas Mexicanas Website identified that as the Donysa Sister, ADELPHA DONYSA DONYSA (genus Adelpha again), and I recall it as among the most common butterflies at that location. Its main difference from our Massilia Sister seems to be in the shape of the orange blotch. Otherwise the similarities are striking. In fact, 33 "Sister Butterflies" -- species of the genus Adelpha -- are listed at the Mariposas Mexicanas Website for Mexico, and some of those species are represented by more than one subspecies. No wonder I find brown, white-barred, orange-splotched butterflies at so many stops. The genus Adelpha seems to have discovered a winning survival strategy, and has been rewarded with an enormous distribution that currently is radiating into many niches, subspeciating as it goes. If only a handful of butterfly species survive the current mass extinction taking place because of human activity, it might be a good bet that an Adelpha species will be among them. ***** ROYAL PALMS Unlike the Chit and Thatch Palms at our last two stops, which were fan palms with the fronds' pinnae radiating from the petiole top, you can see that Royal Palms are "feather palms" whose pinnae arise from a long midrib or rachis. You can compare the above Royal Palm's feathery fronds with a fan-type Chit Palm frond at our recently uploaded Chit Palm page at http://www.backyardnature.net/yucatan/chitpalm.htm. As a group, the genus Roystonea is distinguished by: its tall, columnar, single trunks, or boles; its fronds' pinnae arising at several angles from the midrib so that the fronds look a little shaggy, not neatly flat like a chicken feather, and; having a prominent, green "crownshaft" between the gray bole and its tuft of shaggy fronds. The above picture shows how the palms' crownshafts are formed by the leaves' very broad, overlapping petiole-bases, the petiole being a leaf's stem. The bottom leaves or fronds of Royal Palms always are drying up and falling off as new, larger fronds emerge above them. The flaring petiole-base of a frond lying just outside my door, next to my foot-long sandal, is at http://www.backyardnature.net/n/09/090112rq.jpg. Notice how the Royal Palm's gray bole is narrowly ringed horizontally. Those rings are scars from where old petiole bases have fallen. You can see, then, that during its whole life a Royal Palm drops quite a few fronds and petiole bases like the one pictured one. Old fronds fall mainly during the dry season, which we are into now. Ridding itself of older, presumably less efficiently photosynthesizing leaves can be thought of as a water-saving adaptation. You can see a Royal Palm frond's closely packed pinnae shaggily arising from various angles from the midrib at http://www.backyardnature.net/n/09/090112rs.jpg. Compare that with pinnae systematically arching at just two angles from the midrib of a Manila Palm at http://www.backyardnature.net/n/09/090112rr.jpg. Why would such dignified palms permit themselves such disorderly appearing fronds? I think I know the answer because each morning I build my breakfast campfire beneath a Royal Palm and all during the meal cool water droplets shower onto my bare back. The droplets fall from the palm's shaggy leaves where water has condensed. Typically at this time of year we have morning fogs; the fronds' multitudinous slender pinnae projecting into the air gather fog droplets and combine them into little streamlets of water that drain down the palm's trunk, as shown at http://www.backyardnature.net/n/09/090112rt.jpg. These are very modest streams but here during the dry season after a too-dry wet season, maybe such little streams make all the difference to the trees. I wouldn't be surprised to find that most of this trunk-surface water is absorbed into the trunk directly instead of entering the tree via roots. Three Roystonea species are planted pantropically. There's R. oleracea, the Cabbage Palm originally from the West Indies and with its bole bulging at its base; R. elata, the Floridian Royal Palm from southern Florida, whose bole bulges toward the top producing a "shoulder," and; our R. regia, native to Cuba, and sometimes referred to as the Cuban Royal Palm, with a bole thickening mostly toward the middle. These variously positioned bole bulges provide extra water storage capacity for the species. I've always wondered why trunks in this species bulge, and now I'm suspecting that they may bulge where they most imbibe water draining down their sides. With bulging boles, the discarding of older fronds during the dry season, and dew-collecting pinnae, the genus Roystonea is beautifully adapted for surviving severe dry seasons. ***** NAKED BUDS At http://www.backyardnature.net/budintro.htm I provide an introduction to tree buds, including a picture of five very different twigs showing just how different from one another buds and other twig features can be. Most tree buds up north are covered with scales. If you're identifying woody plants at this time of year up there, you often need to pay a lot of attention to how many scales a bud has, how large the scales are, their color, whether they have dark or pale margins, etc. The other day I began recalling my days of studying buds and scales up north when I passed by a Tropical Almond Tree, Terminalia catappa, and noticed that its large buds bore no scales at all. You can see a Tropical Almond's terminal bud consisting of no more than a cluster of tiny leaves at the branch tip at http://www.backyardnature.net/n/09/090112nb.jpg. In that picture the parallel lines departing from the top leaf's midrib are the future secondary veins. The velvety mantle of rusty hairs will become the future leaves' hairy undersides. Those hairs protect the immature leaves instead of scales. Such buds lacking scales are said to be naked. The picture shows a naked terminal bud. Naked buds often are regarded as features typical of tropical and/or primitive plants -- scales being thought of as relatively new evolutionary innovations more effective than mere hairiness. One group of plants up north with naked buds is that of the Magnolia Family. Next time you walk past a magnolia tree, take a close look at its terminal buds. If there's an oak nearby, compare the oak's terminal buds with the magnolia's, for oak buds are invested with particularly numerous, well developed scales. ***** SIMPLE BUT DIGNIFIED Davidson writes that though Kenya's indigenous civilization "remained simple in most of its material things, in tools and weapons, in means of transport, in housing, in lack of reading and writing, in methods of producing goods, its everyday life became rich and complex in certain other ways. It became a civilization of dignity and value in its spiritual beliefs, in methods of self-rule, in arts such as dancing and singing, in skills that were needed for the solving of problems of everyday life." Before leaving the Yucatán I want to make the point that my experience with backcountry Maya here has been that the above description also applies to them -- and surely the vast majority of other indigenous cultures across the face of the Earth as well. Moreover, here are a few points I think many old Maya I've met would agree with:
***** ON A SYMMETRY IN THE HUMAN CONDITION The Law, if it be one, rules that whenever evolving life reaches a certain stage of sophistication, it engages a certain paradox. On the one hand, eons of "survival of the fittest" have produced an organism that is profoundly aggressive, self-centered and indifferent to the welfare of other organisms. On the other hand, once a being reaches that stage of sophistication, gorgeous feelings, insights and spiritual yearnings spontaneously and irrationally blossom forth, as when the sea speaks to us. This dynamic, heavy on one end with ignorant cruelty and violence but ethereal on the other with artistic and spiritual awakenings, is structured like much of reality. In the real world every deed seems to hold within itself the seed of its own essential oppositeness. Too dogmatic socialism becomes fascist dictatorship. Eat too much good chocolate and you get bad fat. Pray on your knees too much, and your knees go bad. Maybe when the sages speak of yin and yang, the Middle Path in a world of extremes, and maybe even salvation in the context of "original sin," they're confirming this inescapable symmetry of reality's components. And isn't it symmetrical, and maybe a good joke, that we humans consist of a spark of divinity incorporated in animal bodies? The tricky part for humanity is to survive as we pass across that evolutionary threshold where we abandon our instinctual, genetic-based, unsustainable behaviors and begin living in rationally thought-out ways harmonious with Nature's imparted wisdom. Of what good is reflecting on this matter? The good comes from being able to look at humanity and all its misdoings, yet still find hope that there's a bright future for our species. ***** Best wishes to all Newsletter subscribers, Jim To subscribe OR unsubscribe to this Newsletter, go to www.backyardnature.net/news/natnat.php. Post your own backyard-nature observations and thoughts at http://groups.google.com/group/backyard-nature/ All previous Newsletters are archived at www.backyardnature.net/n/. Visit Jim's backyard nature site at www.backyardnature.net |