AUGUST 21, 2016
ARMY ANTS IN THE HUT
Tuesday as I worked in the hut at the computer, something began biting on my ankle. It was a burning, pricking feeling that vanished soon after I brushed away whatever it was causing it. While I was bent over scratching the bite, from the corner of my eye I noticed that the hut's pole wall next to my head somehow seemed to be fluttering or oscillating. When I reared back and looked, I saw that once again army ants were sweeping through. You can see a small part of the hut's interior wall, where the tops of the wall poles meet the thatch roof, with ants swarming into nooks and crannies looking for prey such as spiders and scorpions, at http://www.backyardnature.net/n/16/160821aa.jpg
Having run into army ants many times, we've put together a pretty good page on them, at http://www.backyardnature.net/mexnat/armyant.htm
However, we've never tried to identify them, so this week I've been looking at them taxonomically. In preparation for the task I took many close-ups, but it was hard getting clear pictures, since they were moving fast and I wasn't about to kill one just so I could take its picture. Still, the images show the ants' general form. You can see a scurrying worker at http://www.backyardnature.net/n/16/160821ab.jpg
A worker photographed from above is shown at http://www.backyardnature.net/n/16/160821a8.jpg
That image proved to be the most important one, for it shows that the back of the head is affixed with low, backward-pointing projections, that the end segment (abdomen) is hardly bigger than the head, and that the chest area (thorax) is broadest at its middle, gradually diminishing toward the head, which it joins with a narrow neck. The narrowed thorax front is unusual among army ant species.
At the edge of one ant stream a much larger ant seemed sick or confused, not moving as fast. This larger ant possessed substantial "pincers," or mandibles, and a much broader head to accommodate muscles to enable the mandibles to bite down hard, for this was a soldier, shown at http://www.backyardnature.net/n/16/160821a7.jpg
Wikipedia's Army Ant Page does a good job introducing the subject. There we learn that over 200 ant species are considered to be army ants, but that different ant groups have independently evolved the roving, base-shifting behavior that qualifies a species as an army ant -- convergent evolution.
Learning that most New World army ants belong to the ant subfamily Ecitoninae, a Google search was made for research papers on Mexican Ecitoninae. This turned up the 2004 paper "Las hormigas Ecitoninae (Hymenoptera: Formicidae) de Morelos, México," by Quiroz-Robledo and Valenzuela-González, freely downloadable at http://www.antwiki.org/wiki/images/5/55/Quiroz_%26_Valenzuela_2004.pdf
Mainly using that paper's line drawings of worker ant outlines as seen from above, and noting especially the backward-pointing projections at the back of the head, and the narrowed forward part of the thorax, the best match for the species was NEIVAMYRMEX CORNUTUS
That paper was based on work done in the south-central Mexican state of Morelos, and there's a good possibility that here in the Yucatan we have other army ant species. Neivamyrmex cornutus is endemic just to Mexico. In Morelos the investigators saw the species preying on a termite colony, and in turn saw spiny lizards preying on the ants.
Despite the uncertainty, here we'll file this page on the Internet under Neivamyrmex cornutus, knowing that someday other researchers will confirm or correct the ID, and be happy to see the pictures and read about the species that visited a hut in the Yucatan, and spent most of the day streaming here and there in the hut's backyard.
JUVENILE BIRDS GALORE
Nowadays you see lots of immature birds freshly out of their nests, their undersized beaks and short tails conveying the adolescent look. You can see what I mean on a newly minted Social Flycatcher placidly surveying his new world while perched atop one of the staff's motorbike's rear-view mirror at http://www.backyardnature.net/n/16/160821sf.jpg
You can compare features seen there with those of a mature Social Flycatcher at http://www.backyardnature.net/n/09/091108sg.jpg
The transition between nestling and juvenile bird is a dangerous one. Several times in recent days young birds leaving their nests have crashed onto the floor of the Hacienda's terrace restaurant. Always staff or guests have carefully placed the birds out where the frantic parents could coax them into a shrub or hedge, but you always wonder how such innocent creatures can survive. When one landed next to the room-cleaning staff's breakfast table I asked the fellows what they thought would happen to him. "An iguana will get him," someone said as others agreed.
Last week I was teaching an English class next to the pool when a nestling fell vertically from a nest high in the tree above us. The sickening plop the poor bird made when it hit the concrete, and the humble pile of feathers and broken bones it ended up as, is hard to forget, but that's the way it goes for a lot of them.
It's not only a dangerous time, but also a trying one, because during these first days out of the nest the young bird must change from full dependence on parents for food, to foraging on his or her own. Since any youngster prefers having food plopped into its gaping maw instead of working for it, there's always that moment in the young-bird/parent relationship when the juvenile flies next to a parent who has just come up with something tasty, loudly begging and pitifully fluttering wings, but the parent needs to eat, too, and is kind of getting tired of all this coddling, so maybe there's a brief but sincere conflict, leaving the kid thunderstruck-looking as the parent flies away with its own meal.
It's painful to see such encounters, and one hopes that it goes or went more elegantly in one's own human family.
Right beside the hut's door a knee-high plant has sprung up bearing pagoda-like flower spikes above large, broad leaves with long petioles and regularly toothed, or "serrated," margins, as shown at http://www.backyardnature.net/n/16/160821ac.jpg
A close-up of one of the spikes shows spiny, three-lobed ovaries subtended by deeply cut bracts, or modified leaves, the bracts' divisions forming sharp-pointed bristles, as shown at http://www.backyardnature.net/n/16/160821ad.jpg
The above flowers lack male parts, but when you search below the plant's leaf canopy you find pudgy little spikes poking up bearing male stamens, shown at http://www.backyardnature.net/n/16/160821ae.jpg
Whenever you see separate male and female flowering spikes on a plant, and the ovary is three-lobed, you'd best think of the Spurge or Euphorbia Family, the Euphorbiaceae, and that's what we have here. And when you have a euphorb whose female pistils are each subtended by conspicuous bracts, you should first think of the big, commonly encountered genus Acalypha, and that's also what we have. Acalypha species often are referred to as copperleafs because some of the best known ones display coppery leaves. An ornamental copperleaf much planted here at the Hacienda is profiled at http://www.backyardnature.net/yucatan/copperlf.htm
Just a couple of weeks ago we looked at Acalypha alopecurioides, a wild copperleaf also growing in the hut's front yard, but with short, fuzzy-looking female spikes instead of this species' tall, slender ones. You might enjoy reviewing that other Acalypha at http://www.backyardnature.net/mexnat/acalyph2.htm
Our present species is ACALYPHA SETOSA, native from southern Mexico through Central America and the Caribbean into northwestern South America. It's invasive elsewhere, as in the US Southeast. The USDA calls it Cuban Copperleaf, and such alliterative names often stick whether they're appropriate or not, so we'll go along with it.
Cuban Copperleaf frequents open, disturbed areas, especially cut-over forests, abandoned fields, roadsides and streambanks. You can bet that small, seed-eating birds relish the three tiny seeds that drop to the ground when the three-lobed ovaries split open.
BUCKLEY'S DROPSEED GRASS
In thin soil atop limestone, at the edge of a temporary pool formed in mid-trail passing through the Hacienda's woods, a grass with a long, diffuse head of tiny spikelets was larger than seemed appropriate for the meager tuft of leaves at its base, as shown at http://www.backyardnature.net/n/16/160821sp.jpg
As diffuse, panicle-type, grass flowering-heads go, this one not only was particularly long but also slender, as seen at http://www.backyardnature.net/n/16/160821sq.jpg
In grass identification, one of the first field marks to note is whether the ultimate flower-bearing structures in the flower head, or inflorescence, contain one or more than one florets. You can see that our pool-side grass's spikelets had only one, at http://www.backyardnature.net/n/16/160821sr.jpg
In that picture other field marks that helped in the grass's identification were that the spikelets were purplish to brownish, and that the scale-like glumes at the bottom of each spikelet were thin and shiny, or "membranous," with a conspicuous ridge-like "keel" running down their middles. The mature fruits were egg-shaped, or "ovoid," but slightly flattened. The world of grass ligules -- ligules being the wall-like structures that may or may not form where the blade meets the stem -- is a tremendously varied one, so it's always a good idea to pay attention to them. Our pool-grass's ligule is shown at http://www.backyardnature.net/n/16/160821ss.jpg
All these details led us to SPOROBOLUS BUCKLEYI. Species in the genus Sporobolus often are called dropseeds, so the literature sometimes calls this one Buckley's Dropseed.
Bukley's Dropseed is described as growing at the margins of woods or thorn scrub, sometimes in partial sunlight, from southeastern Texas south to Belize and Guatemala. Here it's neither rare nor common, just showing up occasionally. Its seeds look perfect for small, ground-hopping songbirds such as finches, grassquits and the like.
In local frutarías, or fruit stores, something new has been showing up looking like very large, hairy strawberries. You can see some, one of them opened to show the succulent, pale flesh inside surrounding an almond-like seed, at http://www.backyardnature.net/n/16/160821rm.jpg
At first I thought these were a hairy race of Litchi, or Lychee, fruit, which we met in Querétaro in 2007, shown at http://www.backyardnature.net/q/litchi.jpg
When I peeled off the fruit's tough, leathery, red husk and tasted the sweet flesh, finding it a little like that of a big grape, I was even more sure of it. However, on the Internet I couldn't find such a hairy litchi fruit. But when I Googled the keywords "litchi like fruit," there it was.
These are Rambutan fruits, Rambutan being a medium-sized tropical tree in the Soapberry Family, the Sapindaceae, very closely related to the Litchi. The tree is NEPHELIUM LAPPACEUM, native to tropical Southeast Asia.
Apparently Rambutan fruits are becoming popular throughout much of the world. In the Americas, early Rambutan plantations were planted in the coastal lowlands of Colombia, Ecuador, Honduras, Costa Rica, Trinidad and Cuba. In the 1950s efforts to grow them in the US failed, except in Puerto Rico, mostly because the tree suffers from temperatures below 50°F (10°C).
I read that Rambutan trees do best in deep clay loam or sandy loam rich in organic matter, and thrive best on hilly terrain because they require good drainage. Since we don't have that kind of soil in the Yucatan, I suspect that our local fruits are being trucked here from a fair distance away, maybe Chiapas where such soil is found.
MATURING PITAYA/ DRAGONFRUITS
On a slender branch of Night-blooming Cereus cactus dangling from a tall Habim tree near the Hacienda's parking lot, there's an apple-size growth looking a little like an exotic, headless bird bearing gaudily red, greenish-yellow tipped feathers, as shown at http://www.backyardnature.net/n/16/160821pt.jpg
We've dealt with this cactus a lot, admiring how it adorns so gracefully any kind of tree, bush or fencepost. We've looked into its gigantic, white flowers, and the grapefruit-sized, red fruits that develop from the flowers. The fruits are much eaten by those who know about them, and nowadays during their season they're being sold in local frutarías as pitayas, usually marketed in English as dragonfruits. However, we've never reported on these strange looking fruits in their immature stage, so now we have that.
Our page showing the other life cycle stages of this common epiphytic cactus is at http://www.backyardnature.net/mexnat/cereus1.htm
My Latvian friend Ralfs returned home this week after volunteering at the Hacienda for a month. He'd arrived with a broad smile, wearing an Eastern European-style sports coat and red shorts, and admitting to the dream of being an advertising agent. He endeared himself to the staff by running from horseflies and generally freaking out over iguanas. People still talk about the day he saw a tarantula. Ralfs was unusually outgoing and optimistic, and each day became better adapted to life in the Yucatan. His main strategy for surviving was to ask lots of questions.
Despite having become used to this, I was a little surprised when right before he left he walked into the laundry room where I do my Internetting and seriously asked how one finds inner peace.
First I told him that people are so different from one another that no approach works the same for everyone. Also, with today's fast-evolving, ever-more-stressful world, sometimes inner peace is hard, even impossible, to attain -- as when you're trying to escape a war zone in your homeland.
With that understood, I said that my own first step toward finding inner peace had been to realize that 99.999% of my feeling, thinking and behavior was dictated by my genes, the way my society had programmed me, and randomly occurring events I had no control over. Getting that straight, then I inventoried what I believed, classifying my beliefs into these categories:
This enabled me to slough off many beliefs and behaviors I'd inherited or been taught. It was a disorienting and painful process.
One reason this process can bring inner peace is because our genes and many features of our societies evolved under conditions very different from what we have now, and the sloughing-off process deals with that. For instance, we evolved to crave fatty, sugary, salty food because our ancestors on the African veld had to work especially hard to get those things, but now we need to control our fat, sugar and salt cravings. Our dominant religions were formulated thousands of years ago, and are appropriate for societies of that time, so our spirituality better would be based on new understandings of the Universe. Our dominant political and economic philosophies are rooted in the 19th Century notions that we live in a world with unlimited resources, and that the planetary ecosystem can absorb unlimited human abuse, so we should stop thinking like that.
When you stop behaving as if you were still on the African veld, and start reacting to realities you see around you, things go smoother. Inner peace.
And then there's that 0.001% of one's mentality that sometimes for a millisecond is zapped into an awakened state when we look into the starry sky, or a baby's eyes. Sometimes I think that during those electrifying moments we get a peep into whatever is responsible for the Universe in the first place. Who knows what it is, but if you've experienced it during those lightning-bolt moments, you've recognized it, and know what I'm talking about.
Once this thing is recognized, you can begin consciously seeking experiences during which it occurs. Some find it in formal meditation, or living very simply. Mostly I've found it in Nature. The more it's experienced, the more peace it bestows, and the likelier it becomes for the feeling to linger, and reveal new inner territories open to peace and beauty.
And, why is "inner peace" an appropriate topic for a Naturalist's Newsletter? It's because Earth's natural things everywhere, right now, are suffering and disappearing because of behaviors of humans doing what their genes and local societies inappropriately program them to do: Produce more and more babies, possess and consume more and more, wave the flag, brandish Holy Scripture, make war on "the other"...
Thing is, the people I've known who seemed most at peace with themselves, on the average, didn't do much of that.
Best wishes to all Newsletter readers,
All previous Newsletters are archived at http://www.backyardnature.net/n/.