November 17,  2008

DOWN IN THE WEEDS
Tuesday morning a couple of hours after sunrise I was winding my way through a 20-acre patch of weeds surrounded by forest, maybe an abandoned cornfield or the remains of an area scalped for charcoal making. It was a waist-high, emerald-green sea of dew-wet morning-glory vines sprawling over annual herbs and grasses. I was approaching a flock of about a dozen tightly clustered, black Melodious Blackbirds perched atop weeds making curious, sharp piik! piik! piik! calls.

Something was going on there upsetting the blackbirds and I had an idea it might be a snake. As I approached the complaining birds they flew away, and then I could hear another bird desperately issuing its distress call. "Snake has a bird," I thought.

The weeds were so thick that I couldn't see a thing unusual from four feet away. A bit closer something yellow down in the weeds' shadows showed up; I watched as the yellowness rose higher inside the weeds, but, suggestively, not under its own power. It was being pulled upward by something. Now I could see that it was clearly a levitating bird, one belly-up, probably an immature or female Hooded Oriole, but where was that snake?

Less than three feet away finally I saw what is shown in the at-first-maybe-hard-to-interpret photo at https://www.backyardnature.net/n/08/081117or.jpg.

Can you see the actors in this drama? Several people here looked at the photo for over a minute before they discovered the bird. Even with my face just inches from the real thing it took awhile before I realized that the green form at the picture's top right wasn't a leaf but rather the beady-eyed head of OXYBELIS FULGIDUS, the Green Vine Snake. Can you see the bird's toenail almost sticking the snake in the eye? It looks like the oriole's beak and forehead are caught in the snake's mouth.

In the photo you can barely make out how the snake's body narrows drastically behind the head. It's remarkable that such a large bird can be ingested into such a slender body. Several times I've seen Green Vine Snakes dangling vinelike in trees and their bodies always strike me as so absurdly slim that it's hard to imagine their meager musculature enabling them to climb trees, much less subdue prey much larger than themselves.

Jonathan Campbell in Amphibians and Reptiles of Northern Guatemala, the Yucatán, and Belize writes that Green Vine Snakes feed heavily on birds, but also rodents, anoles and other lizards. The snake tends to wait for prey to come within reach instead of foraging actively. I was surprised to find it in the center of a large, weedy field because it's considered an arboreal species.

Green Vine Snakes, which reach at least 6.5 feet long (2 m) are distributed from Mexico's Isthmus of Tehuantepec southward to Argentina. Because of this large distribution, its relative commonness and striking appearance it's among the American Tropic's most representative reptilian species.

*****

ROADSIDE HAWK
Right after dawn along the road to Mexil I heard a hawk screaming, MEEEAHHH! MEEEAHHH! then a smallish, brownish, buteo with rounded wings and fairly long, narrow tail crossed the road and vanisheded. From his continuing calls I knew he was perched in a tree off the road, probably beyond sight. I continued down the road looking for an opening in the dense forest where I might spot him.

Instead of an opening I found the hawk's companion in plain view on a limb right beside the road. As the other called and called out of view, this one just looked down at me, with the sun behind it, thus silhouetted. I took a picture anyway and later with PhotoShop coaxed into existence the faded picture at https://www.backyardnature.net/n/08/081117rh.jpg.

This roadside hawk is a Roadside Hawk, BUTEO MAGNIROSTRIS. Roadside Hawk is the English name field- guide authors have settled on, and I have to agree that the species shows a special affinity for roadsides.

Good field marks for soaring Roadside Hawks include their relatively long tails held closed in flight and with two or three broad pale bands across them, and vague, rusty-red blotches on their outer wings -- "rufous panels in primaries," as Howell says.

The bird didn't seem to want to move. In my pictures I saw that either it was holding one leg up inside its feathers, or it was one-legged. Because of its hesitancy to fly, I suspect the latter.

*****

WARBLER QUIZ
To a certain subset of North American birders, "birding" mainly means "warbler watching." Field guides are published just for warbler watchers, and I myself know the extreme pleasure in seeing those tiny, often yellow-and-black members of the Wood-Warbler subfamily, the Parulinae, as they migrate northward in spring, southward in the fall. Especially back in the 60s and 70s when many more warblers existed, I was lucky enough to live in the Mississippi Flyway, much used by warblers.

During spring migration singing warblers are at their brightest as they feverishly forage for food in trees, refueling after their long flights from the south, and often needing energy for flying farther north. Returning in the fall, they're quiet, their colors usually are much subdued, and they progress along their migratory routes relatively secretively. Often but not always the male's plumage is very similar to the female's, which is fairly drab and often is itself similar to female plumages of other warbler species. Drab, silent, overwintering warblers in Mexico can be a real challenge to identify, especially because about 66 species are listed for the country.

If you're a warbler-watcher, try you hand identifying the much-changed-from-summer, recently arrived warbler who this week let me snap the picture at https://www.backyardnature.net/n/08/081117bt.jpg.

A good hint is that the dark smudge beneath the throat is produced by dark feathers -- didn't disappear when the bird changed position or got into brighter light.

I'm calling this an immature or female Black-throated Green Warbler, DENDORICA VIRENS. I'm not sure I'd have the courage to ID it if I should see it back in Chiapas or Querétaro, for in most of Mexico immature Townsend's Warblers look a lot like it. However, Townsend's Warblers are upland birds not found in the Yucatán.

During summers Black-throated Green Warblers nest in Canada and the northernmost of the US's eastern states, and winters from central Mexico to Panama. I can remember spring woods along the Mississippi Flyway swarming with these birds, their wheezy EEE-EEE-uh-EEE calls sounding all around. What grand memories and how glad I am to see that this one survives despite all the challenges against it.

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ALMOST A MONARCH, BEA SAYS
There's a butterfly around here that's almost a Monarch, but not quite. You can see what I mean at https://www.backyardnature.net/n/08/081117mo.jpg.

You might find it interesting to match that picture with one of a Monarch, maybe in a field guide or on the Internet. Monarch Butterflies are Danaus plexippus. The picture shows DANAUS ERESIMUS ssp. MONTEZUMA, whose English name is Soldier. Because the two species belong to the same genus, Danaus, it's clear that they're closely related. There's another Danaus in Mexico known as the Queen.

I know all this because Bea in Ontario told me. Those of you who drop into the Backyard Nature Forum at http://groups.google.com/group/backyard-nature/ probably have seen Bea's postings and pictures.

Bea has helped me a lot, even contributing her own page at my Backyard Nature Website, one featuring a series of photos documenting a cluster of Mourning Cloak Butterfly eggs, from the moment of their deposition to the fuzzy caterpillars' release. It's at https://www.backyardnature.net/m_cloak.htm.

Currently at the Backyard Forum Bea has uploaded many pictures of my unidentified Mexican butterflies, and invited everyone interested to try their hand at IDing them. She writes:

Eventually I hope to produce a page on Yucatan Butterflies like the one already online for Chiapas at https://www.backyardnature.net/chiapas/butter01.htm

Of course everyone out there is welcome to help with IDs and improving the Backyard Nature website. Because I can't spend much time on the Internet, many of my pages are woefully out of date, have broken links, etc.

*****

VIEW INSIDE A PAPER WASP NEST
Often I've mentioned how frequently paper wasp nests of various shapes and sizes show up here. The other day I came upon one with its exterior partly torn away and I thought you might be interested in seeing the layers of hexagonal cells inside it. The picture is at https://www.backyardnature.net/n/08/081117wa.jpg.

When I showed the picture to a friend here I got the usual report on how tasty the wasp grubs are sautéed with a little salt and chili sauce.

*****

A FAMILY OF FIREWOOD GATHERERS
In highland southern Mexico and some other parts it's an everyday thing to see firewood gatherers trudging down the road with loads of firewood on their backs. Several families gathered in Sabacché.

Here on the main highway across the northern Yucatan, however, people in general are more prosperous economically than in the little villages in the interior, and I'd figured that most families here cooked with gas delivered at their homes in metal cylinders.

However, the other day a family of four passed by loaded with firewood, catching my attention. They were well dressed and seemed a little embarrassed to be seen carrying firewood. You can see them at https://www.backyardnature.net/n/08/081117fg.jpg.

I asked a friend about the situation with regard to firewood use for cooking in Yodzonote and she said:

"In the old days of course everyone used firewood, but then gradually people starting cooking with gas. Then the price of gas went up and now more and more people are returning to firewood. I use firewood exclusively. Tortillas bake faster with firewood, anyway... "

*****

POISONWOOD
One tree around here anyone who works in the woods learns early is the Poisonwood, METOPIUM BROWNEI, in Maya known as Che Che'en. Its alternate, pinnately compound, wavy-margined leaves are shown at https://www.backyardnature.net/n/08/081117pw.jpg.

Being acquainted with this tree is important because if you get the tree's sap on your skin your skin may itch, develop a rash, and even break out in running, scar-leaving blisters. Poisonwood belongs to the Poison-Ivy or Cashew Family, the Anacardiaceae, so that explains a lot.

Besides its compound leaves, which are similar to those of ash trees up north, a good field mark to help in identification is that often the tree's trunk bears black, tar-like blotches, where sap has dried, shown at https://www.backyardnature.net/n/08/081117px.jpg.

When Poisonwood sap first begins emerging from a wound on the tree it's clear. In about ten minutes it turns to a bright, rusty-red hue, then after 20 minutes it's black, and it stays black.

My impression is that Poisonwood sap causes much more than a mere allergic reaction. Most of my life I've experienced no symptoms at all when exposed to Poison Ivy, even its sap smeared on my skin (I seem to be losing some of that immunity now, however.) Still, my skin reacts to Poisonwood sap as if it were a very strong acid, producing running blisters.

*****

FERN CREEPING ALONG A STEM
One night this week I camped beside an isolated cenote. During the night I could feel and smell the balmy, musty humidity issuing from deep inside the sinkhole. That humidity nurtured certain plants at the pit's rim not typically found elsewhere in the drier forest. One such plant was the fern showed at https://www.backyardnature.net/n/08/081117mc.jpg.

I think that that's the genus Microgramma, and since there's only one Microgramma, MICROGRAMMA NITIDA, listed for the adjoining state of Quintana Roo (no flora for Yucatan state), I'm guessing that it's that.

Northerners will regard this as a curious fern not only because its fronds consist of single, willow- leaf-like blades lacking the frilliness typical of most fronds, but also because its fronds grow widely spaced along somewhat woody stems that creep along supporting branches.

The dark, round spots on the undersurface of each frond are "fruit dots" or sori, which are clusters of tiny capsules that open to release spores. Such round sori are bound to remind northern fern fanciers of the Polypodies often seen up there gracing mossy rocks in the north and tree trunks in the Deep South. Microgramma is closely related to the Polypodies.

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THE HETERODOX MORNING-GLORY
The several morning-glory species introduced in this Newsletter so far represent just a small sample of the Morning-Glory Family members found in this area. The Flora of Quintana Roo, Quintana Roo being the state to the east, lists 34 species in the family. One of the most unusual, common along roads here, is shown at https://www.backyardnature.net/n/08/081117ip.jpg.

With its broad throat and deeply incised leaves it hardly looks like a morning-glory at all. However, it does possess all the technical features needed to belong to the family: Twining stem; corolla shallowly lobed instead of divided into separate petals; corolla basically funnel-shaped; corolla twisted in the bud; five stamens inserted deep in the corolla tube; ovary superior, etc.

It's IPOMOEA HETERODOXA, which I'm calling the Heterodox Morning-Glory because I can't find any other name. Its heterodoxy lies in those deeply cleft leaves and wide-throated corolla.

*****

WHEN DRUNKS GIVE THE EVIL-EYE...
In a pamphlet I'm writing to be sold to visitors to the cenote I'm including a small section on the local use of medicinal herbs. While interviewing a friend about the uses of this and that plant, we came to the common vine called Popox in Maya.

"It's used against the evil-eye (ojo malo) drunks give babies when they look at them," my friend said. I asked for an explanation.

"When men are drunk sometimes when they look at babies they give the evil-eye, and the baby gets diarrhea. You bathe the baby in water prepared with Popox root to undo the evil-eye."

Just when you think the people you're around have their heads entirely in the cell-phone, TV, go-to-the- ciber world, you realize that inside those heads there are still vast acreages of magical, dangerous territory.

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SNAKE TAO
Seeing the oriole dying in the snake's mouth affected me on several levels. When confronted with unsettling situations my default behavior is to set myself apart from the moment by identifying with its universal context, and that's what I did this time:

Down in the dewy, still, chilly shadows what I saw was both awful and majestic. It was a critical node in a stream of energy that began at the sun, passed through space, and upon arriving at Earth fell onto this field's weeds. Here through photosynthesis the light's solar energy was stored in carbohydrates incorporated in the weeds' bodies. Eventually that stored energy was conveyed to the oriole, either via insects who ate the weeds' leaves and then got eaten by the oriole, or via weed fruits the bird ate. Now I was seeing that energy about to be imparted to the snake, who later would pass it to a hawk or maybe decomposition organisms if it dies from other causes. In this light, down in the weeds, everything made sense, everything was just hunky dory.

But, philosophical frameworks quickly dissipate, for constantly maintaining them takes psychic energy, and that psychic energy always is needed elsewhere, to deal with "real life" like work, itching mosquito bites and the like. Hiking the trail back to Yokdzonot already my "universal" perspective was wearing thin. Images of the oriole's tail feathers so pathetically spread in the bird's death-throes, of its feet so uselessly clutching the snake's face, reminded me that we humans, too, reside in biological bodies, every one of which right now is proceeding inexorably toward final degradation.

By the end of the trail, after a lot of reflection on the biological realities of humanity, I'd decided that in the long run the most consequential feature distinguishing humans from other animals is our ability to accumulate knowledge and experience, and pass it on to later generations.

In that light, because all the Universe's happenings are part of an evolution toward something, and at this stage human evolution takes place mostly in the intellectual realm, it occurred to me that the highest calling available to us, besides living itself, is the systematic accumulation and use of intellectually acquired facts. Information, you could say, is sacred. Science is a spiritual pathway. Obfuscation and spreading false information are sinful...

Breaking from the forest trail into sunlight and realizing that in just a few minutes I'd gone from a bird in a snake's mouth to "Obfuscation is sinful," I had to laugh.

But, that's how it is when Nature speaks to you. Nothing in reality is a straight line, nothing stays for long unchanged by other things, nothing is all one way and not the other, seeds of everything lie within seeds of everything else, so real understanding grows from hidden, crooked roots.

The Tao says that the moment you begin speaking of the Tao you're no longer speaking of the Tao.

Therefore, Nature speaks in terms of green snakes holding yellow birds in their mouths.

*****

Best wishes to all Newsletter subscribers,

Jim