from the woods near Natchez, Mississippi, USA
August 24, 2003
BLACK RACER EATS FROG
Walking down Cooper Branch's dry, sandy bed, a flicker of movement caught my attention at the corner of my vision. I looked up just in time to see a tangle of frog legs and loopy, black snake-coils rolling down the creek bank like a rubbery tumbleweed. I'm only half sure the victim was a Southern Leopard Frog, for most of its body already was inside the snake's mouth and throat, with just its flailing legs and head showing. The snake's identity was clear, however: It was a Southern Black Racer, COLUBER CONSTRICTOR PRIAPUS. You can see this handsome, slender, black snake at www.stetson.edu/~pmay/PHOTOS/racer2.jpg
On the streambed's sandy floor there was still some fighting to do. The frog's four powerful legs scratched, pounded, pushed, and held on in every conceivable manner to slow the body's slide down the snake's gullet. The snake, in turn, with no limbs at all, could only try to hold on. Racers possess only regular teeth in both jaws, with no enlarged fangs with which to stab into their prey, so sometimes it looked as if the frog might succeed.
However, after about five minutes the frog tired and blood issued from its nostrils. Sensing victory, the snake made a series of forward lunges, each advance taking the frog deeper inside. In the end only one arm -- unnervingly like a small human arm bent at the elbow and with fingers spread wide in alarm -- poked from the snake's mouth corner. Then even that vanished.
The racer hardly missed a beat. As soon as the meal was definitely inside, instantly the search for the next victim began as the snake moved back to the overgrown slope and disappeared inside it.
Something special about racers is that, when they hunt, the back 3/4ths of their bodies move across the ground while the front quarter rises vertically, with their heads at the top hooked forward and held horizontally. Thus, when we see them, usually the snake's back part is hidden in the grass while the front, high-held part with the hooked head seems to progress forward by no visible means of propulsion. Such a snake with its unblinking eyes' fixed forward makes a majestic, spine-tingling passage through tall grass.
Tuesday at dusk the first blossom appeared on my Moonflower vine, CALONYCTION ACULEATUM. This is a much-planted, tropical member of the Morning-glory Family and I'll bet that at least half of this newsletter's readers have their own fond memories of waiting at dusk for a Moonflower to blossom. If you have Quicktime installed on your computer you can watch a movie of a Moonflower blossom opening at http://sunflower.bio.indiana.edu/~rhangart/plantmotion/flowers/moonflower/moon.html You can download the Quicktime program for free at http://quicktime.apple.com/
The Moonflower knows how to build up suspense as the moment of blooming approaches. For several days you are impressed by the development of the large, green flower-bud. By Tuesday evening my bud had grown to exactly 6 inches long (15 cm). An hour before sunset the bud's spiraling pleats began bulging, revealing streaks of the flower's pure whiteness within. I placed my rocking chair next to the 17-ft-high vine (5 m) and waited. At first the blossom's opening proceeded too slowly to see, but, finally, exactly as the sun slipped below the horizon, and the flower was held closed only by the tips of its petals, suddenly the tips came loose all at once and the flower partially opened instantly, releasing a puff of perfume that almost staggered me.
At dawn the next morning the flower's corolla closed like a crumpled paper bag. All day it remained shut beneath the bright sun, then an hour or two before dusk it fell off, leaving the ovary to develop into a fruit. That evening, Wednesday, two more blossoms opened, and I've had one to four blossoms each night since.
It happens that this week my friend Ana María near Mérida in Mexico also has been watching her Moonflower. On the night she expected her first bloom she invited friends to experience the opening. They had a fine supper, then went out to see the opening -- and the entire flower bud that was supposed to open had been eaten by caterpillars! However, in two nights there was another bud to watch, and once again the friends came, there was a delicious meal topped off with an exquisite "tarta de manzanas," or apple tart, and this time the blossoming surpassed expectations.
How lucky we are to live in times when such gentle ceremonies are possible.
CAROLINA SPHINX MOTH
Wednesday night as I awaited the Moonflower blossoming, a large, fast-flying Carolina Sphinx Moth, MANDUCA SEXTA, came visiting my Four O'clocks, which at dusk were graced with dozens of fragrant, magenta blossoms. This moth, the adult stage of the Tobacco Hornworm, is the size of a hummingbird and its narrow wings beat with a blur just like a hummingbird's. This is a beautiful instance of convergent evolution, in which two very unrelated forms of life evolve to look like one another because they occupy the same ecological niches. In this case, hummingbirds occupy the niche during the day while sphinx months take up the job at night. You can see a Carolina Sphinx Moth at http://entweb.clemson.edu/museum/moths/local/moth1.htm
Just before the Moonflower blossom opened, the sphinx moth suddenly broke off its serial visits to the Four O'clock flowers and shot in the direction of the Moonflower. Zigzagging back and forth, apparently searching for the source of the Moonflower's perfume, within seconds it managed to locate its target. Again and again it tried to insert its long proboscis into the unopened blossom, but it was impossible. As darkness grew the moth returned several times, and when finally the flower puffed open, you should have seen how eagerly the moth set its tube into the blossom's deep throat.
FLESH FLY AND HORNWORM
I do not wonder where the sphinx moth came from. Since earlier this summer I discovered my body's sensitivity to the immoderate eating of members of the Nightshade Family, I have viewed my tomato plants more as ornamentals than food producers, and as such I have enjoyed watching a series of Tobacco Hornworms grazing the plants.
Wednesday during a late afternoon visit made to two hornworms known to be grazing a certain plant, I was surprised to find the caterpillars quiet, their heads curled beneath them. Looking closer, I saw that the larger caterpillar was blotched with dark green, moist areas, as if bruised, and that a fly was pestering it.
The fly looked a lot like a regular housefly, except that its compound eyes were conspicuously pale tan, the fly's back was striped with silvery lines, it buzzed louder than a housefly, and its aggressive behavior toward the caterpillar was very unlike a housefly's nervous manner of being. Realizing I had a different kind of fly, I got my field guides and handlens, the fly landed and remained still while I looked it over, and I determined that it was one of over 300 North American species of Flesh Fly, of the family Sarcophagidae -- a fly very different from houseflies, blow flies, tachinid flies and the rest. You can see this neat-looking little critter at www.inhs.uiuc.edu/cee/biocontrol/parasites/graphics/sarcophagidae.gif
Soon the fly was at the hornworm again, and this time I saw that frequently he would actually land on the caterpillar for a second or two, and that during that brief landing a tiny, white egg would be laid on the hornworm's green body. The hornworm realized that this was not good news, for again and again it bent its body around and attempted to scrape the eggs off. It couldn't reach its rear-most parts, however, or the region right behind its head, and these were precisely the bruised-looking areas, and the spots where the fly laid most of its eggs.
My fieldguide explained what was happening. Larvae from the eggs would enter the hornworm's body and tunnel through it. Eventually the hornworm would die, but not before the larvae were ready to burrow to the hornworm's skin, where they would metamorphose into adult flesh flies. Most flesh fly species are scavengers, some develop in skin sores of vertebrate animals, and a few feed on insects stored in wasp nests, but clearly here I had one of the several species who parasitize caterpillars.
On Wednesday, the hornworm, the flesh fly, the Four O'clocks, the Moonflower, the sphinx moth, and I all mingled in a congenial, interconnected, mutually sustaining permaculture ecology.
INLAND FISHES OF MISSISSIPPI
When friend and nature-photographer Jerry Litton of Jackson read that I was struggling with the identification of the "minnows" in Cooper Branch running by the barn, he lent me his copy of "Inland Fishes of Mississippi," an impressive book by Stephen T. Ross, published in 2001 by University Press of Mississippi.
This is a wonderful book with 624 pages of fine color photos, drawings, distribution maps, and well- thought-out text. I was unable to take ichthyology in college because I refused to kill fish by making collections. Same with entomology and insects. With good books, over the years I taught myself a lot about insects. However, only now has this book opened to me the world of freshwater fish. What a pleasure it has been this week, at the age of 55, to be discovering for the first time the wonders of a whole new corner of the natural world.
As always, a new world is most effectively explored systematically. A few basic insights provide a nucleus around which further information can be organized. Here are some of the basics about the inland fish of Mississippi:
About 970 freshwater fish species are known for the US. Of these 970 species, 288 occur in Mississippi. Among all US states, Mississippi ranks fifth in number of species, with only Tennessee (297 species), Alabama (257), Kentucky (220) and Georgia (219) having more. In terms of freshwater fish worldwide, the US Southeast has been referred to as a "piscine rainforest" because of its richness of fish species.
A hierarchical system has been developed for thinking about the inland streams serving as fish habitats. The small streams and creeks right around us here are part of the "Homochitto River SYSTEM," which is part of the "Lower Mississippi South DRAINAGE," which is part of the "Mississippi River BASIN." The state of Mississippi is served by two basins, the other being the Gulf of Mexico Basin. The boundary between these two very large basins cuts across Mississippi from the southwest to the northeast corners. In the world of fish, this boundary between river basins is approximately as significant as an international boundary among humans.
Our "Lower Mississippi South Drainage" is honored by being the home of an endemic species -- a fish that on the whole Earth is found only here -- the Bayou Darter, ETHEOSTOMA RUBRUM, of the Bayou Pierre System near Port Gibson.
Mostly because of habitat destruction, with stream channelization being a prime culprit, many of our fish species are endangered. Specialists have written that "the South is on the brink of an extinction crisis in fishes in which more taxa may be lost than the total native fish faunas of some western states!" In Mississippi, 71 species comprising 35% of our native fish fauna are to some degree imperiled.
So, finally, what's the name of the "minnow" in Cooper Branch next to the barn? Without dissecting a fresh fish, I'm about 70% certain that it's the Ghost Shiner, NOTROPIS BUCHANANI.
You can review "Inland Fishes of Mississippi," and buy it new for $35 (possibly $20 used) by clicking here.
This week Vickie C over at McComb, Mississippi wrote that once she'd been an Adopt-A-Stream monitor in her area. I'd like to monitor the water in Cooper Branch running next to the barn, so I Googled up information on the Adopt-A-Stream program.
From what I can see, each state has its own program. Mississippi's is introduced on the Web at www.mswildlife.org/adoptastream.html If you want to find out about the program in a state other than Mississippi, just Google the keywords "adopt a stream ****," with **** being your own state's name.
In Mississippi you can sign up to be a "Stream Steward," in which case you might be expected to do seasonal litter pickups, storm drain stenciling, streamside management and restoration, advocacy work, or any number of other such activities.
If you want to be a full-fledged "Volunteer Monitor" the way Vickie had been, you must attend a training workshop to learn to survey and map your adopted stream's watershed, and to conduct chemical and biological monitoring. The workshops take place twice yearly at Mississippi state parks and are conducted by water quality specialists. Space in each workshop is limited.
Well, the expense and required travel precludes my being a Volunteer Monitor, and I don't need to join them to pick trash from the stream, which I do all the time. However, I still think this is a pretty good program for anyone interested in protecting their local streams. It seems that being a Stream Steward would make a perfect class project.
MARS AFTER 60,000 YEARS
On Wednesday, August 27th, Mars will be at its closest to Earth for nearly the last 60,000 years. Already it is a majestic presence in the night sky, the brightest thing up there after the Sun and Moon. It rises in the East around sundown. The best view is during the middle of the night when it's well overhead.
Its size and strange reddish hue seem so unnatural to me that when I see it I am visited with a certain sense of unease. I can only imagine how people 60,000 years ago during its last close passage must have reacted. Surely they worried that it was a bad omen.
In fact, if 60,000 years ago people considered Mars's unnatural appearance a bad omen, they may have been right. For, 60,000 years ago the Earth was about to be plunged into the most recent Ice Age, which ended only about 10,000 years ago. I wonder if the current visitation might also be an omen? For, today some computer modeling of long-term climatological changes suggest that at any time the Earth's climate may experience sudden drastic changes. In particularly, a profound shift toward much COLDER weather in Europe could occur.
This abrupt and devastating shift could result from the disruption of the Gulf Stream ocean current, caused by the enormous amounts of fresh water currently being introduced into the Atlantic from the melting of Arctic ice, because of global warming. You can read about the disruption of this "Ocean Conveyor Belt" and the Atlantic's "thermohaline circulation" in a rather brain-numbing article at the US government's NOAA site at www.aoml.noaa.gov/phod/acvp/gray.htm
By the way, the Planetary Society's "Mars Day" site with info and activities is at www.planetary.org/marswatch2003/marsday.html
LARRY'S MOUNTAIN MINT
The other day Larry Butts up near Vicksburg wrote me that he'd checked "Wildflowers of Mississippi" from the local library there. He wrote: "I walked up the gravel road for a ways and gathered some flowers and came back to the house and have been able to identify some but not all." Mainly he was curious about "the dominant plant along the roadside across from my house. Whatever it is, the butterflies are swarming on it."
Larry emailed a picture of his mystery plant and I identified it as one of several species of Mountain Mint, genus PYCNANTHEMUM, of the Mint Family. Once he knew the genus, Larry Googled up a page on the Internet with a picture matching his find. It's at www.missouriplants.com/Whiteopp/Pycnanthemum_albescens_page.html
Mountain Mints are wonderful plants, and in our area they are pretty common along roadsides through dry woods. They have tight little clusters of small, dog- faced blossoms that usually are white with purple spots -- and the crushed herbage smells very minty, indeed. As Larry wrote, "I crushed some leaves up and my hand smelled of mint. I wish I could find some chewing gum that tasted so good! Thank you so much for putting me in touch with this marvelous piece of nature. I always just looked at these plants and called them weeds. Never again!"
Larry's letter just tickles me. It reminds me of delicious times I myself experienced decades ago learning the names and special features of common plants I'd been around all my life, but somehow had managed to ignore.
So, this week Larry became sensitized to Mountain Mints, and doors swung wide to me for the inland fish of Mississippi. Both Larry and I are old farts who've seen a bit of life, and now, just because we're still looking at things, wondering about them, and willing to make an effort to learn more, we're still making discoveries that make us happy, he with his book and gravel road, me with my book and an old barn next to a woods and a field.
If any of you are feeling a little stale, I hope you'll think about what Larry and I have been up to this week, get up and go discover something for yourself that's nearby, common, and wonderful as a Mountain Mint or a Ghost Shiner.