NATCHEZ NATURALIST
NEWSLETTER:
from the woods near Natchez, Mississippi, USA

May 23, 2004

ALLIGATOR IN PIPES LAKE
Pipes Lake is a pretty little impoundment maybe ten acres large in Homochitto National Forest some six crow-miles south of here. Visiting there this week I saw an alligator -- known formally as the American Alligator, ALLIGATOR MISSISSIPPIENSIS.

For years I've heard about Pipes Lake's "big alligator." Maybe there's one or more big ones there but the one I saw was only about 30 inches long (75 cm). It was so lethargic that amberwing dragonflies appeared to be laying eggs on its loglike snout. I may be wrong but it looked like it had a bullet hole in its back.

By clicking here You can read an article entitled Mississippi's Alligators. That page tells us that currently 32,000-38,000 alligators live in Mississippi, and some 408,000 acres of alligator habitat exist. Today alligators are found in all of Mississippi but for 14 northern counties. Since alligators are not hunted by the public in Mississippi, as they are in Florida and Louisiana, ours get larger. In fact, 22% of alligators counted along the Little Sunflower River in Yazoo and Sharkey Counties in the Delta were greater than 10 feet long (3 m).

So, that alligator just lay in the water with his two bulging eyes and the ridge of his snout above the waterline, not doing much I can tell you about. But, when you're an alligator, you don't need to do much to get noticed.

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SPINY SOFTSHELL TURTLE
A female Spiny Softshell turtle, TRIONYX SPINIFERUS, put on more of a show. While the alligator behaved like a log, the softshell swam about as if exploring things, cruising among snags and in and out of little bays, sometimes diving out of sight and sometimes staying at the water's surface for minutes at a time, always moving fluidly as a ballerina representing a swan. This was a fair-sized individual, the shell about a foot long, and the head and neck extending well beyond that.

Softshell turtles are easy to identify because of their flattish, pancakelike shells covered with soft, leathery skin instead of horny scales, or scutes. Even more different from regular turtles, softshells possess sharp, tubular snouts that serve as snorkels when the turtle travels just below the water's surface. You can see a close-up of a softshell's head at www.nationalgeographic.com/lewisandclark/record_species_047_20.html

Though this species lives in small, marshy creeks and farm ponds as well as large rivers and lakes throughout most of the central US, I don't see it often, so I was actually more excited about spotting this turtle than the alligator.

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ANHINGAS SPREADING THEIR WINGS
As if the alligator and softshell turtle weren't enough, Chimney Swifts kept Pipes Lake's water splashing as they flew along its surface, scooping up water on the wing. Easier to watch were the Anhingas, ANHINGA ANHINGA, who between long dives underwater swam with nothing but their snaky necks and heads above the water's surfaces. Anhingas look a lot like cormorants, except that their beaks are sharp, not hooked at the end like a cormorant's, plus there's a lot of white in the anhinga's mostly black wings, while cormorants have uniformly dark wings.

The most striking thing the anhingas did was to climb onto a snag emerging from the water, spread their wings and tails, and hold them against the incoming sunlight, frequently fanning and shaking them. This well-known Anhinga behavior is shown in an image at www.sccf.org/Birds/anhinga.JPG

While watching the wing-spreading, a question came to mind: Since Anhingas have no more exposure to water than ducks, why do Anhingas spend so much time drying their wings while ducks don't? Gradually I began coming up with an answer as it occurred to me that often I see ducks preening -- smearing waterproofing oil from their preen glands over their feathers -- but I don't remember ever seeing Anhingas doing this. Maybe Anhingas don't have preen glands, I decided. Moreover, since Anhingas are such primitive-looking birds, maybe they don't have preen glands because they came into existence before the bird-world evolved preen glands.

This made such a great story that I almost didn't check it out. However, I did, and found an article entitled "Why do Anhingas spread their wings?" at www.audubon.org/local/sanctuary/corkscrew/Wildlife/Birds/Wing_spreading.html

There it's stated that Anhingas have unusually low metabolic rates and unusually high rates of heat loss from their bodies. Moreover, they don't have to be wet to exhibit spread-wing postures. Since they typically orient themselves with their backs to the sun, it's deduced that Anhingas spread their wings mainly to absorb solar energy to supplement their low metabolic heat production and to offset partly their unusual high rate of heat loss. Wing-spreading is mainly a thermoregulation behavior, not a drying one. Moreover, the newest insights from genetic sequencing don't appear to support the idea that Anhingas are especially primitive, despite their look.

Still, it's clear that when Anhingas emerge from the water they do want to dry off, for they very plainly agitate their wings and you can see water being shaken off them.

By the way, that nice word "Anhinga" proves to have passed into English from Portuguese, which took it from the Tupi name for the bird, "ayingá." Tupi is a member of the Tupí-Guaraní language stock of coastal and central Brazil and Paraguay. We can deal with that since Anhingas are found from here all the way to southern Brazil.

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AMBERWING DRAGONFLIES PLAYING LIKE WASPS
The amberwings trying to lay eggs on my alligator were Eastern Amberwings, PERITHEMIS TENERA, and they're found from New England to Nebraska and New Mexico, southward to the Gulf Coast. This is an abundant, easy-to-recognize species (it's small, chunky and amber-colored), and you can see one at www.iowaodes.com/skimmers/amberwing.asp

You might wonder how such a conspicuous insect with apparently few defenses can be so common in an area teeming with birds, frogs and other critters who'd seem very interested in eating it. One answer is that amberwings resemble wasps, especially the aggressive, amber-colored species we have who will sting you even if you're perfectly still. Amberwing abdomens are marked with narrow, pale-yellow bands like wasps, and this dragonfly will pulse its abdomen up and down while simultaneously waving its wings just like a wasp. Females even fly with their hindwings and abdomens held in a wasplike manner.

This kind of inter-species mimicry is common in the insect world. Some of the most innocuous flies look too much like bees and wasps for many predators to eat them. Viceroy Butterflies look like Monarch Butterflies, who are so bitter that most birds leave them alone. Mother Nature knows what anybody knows who grows up in a rough neighborhood: If you're not mean yourself, sometimes it helps to at least look mean.

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IRIS BLOSSOM SHENANIGANS
Last week I made the point that magnolia blossoms are primitive in the sense that the first flowering plants to evolve bore blossoms that were magnolia-like. In contrast, among the most modern flower types to evolve are orchids and other monocots, such as the irises. The average backyard iris blossom displays several very interesting modifications and specializations you'd never see in a primitive-type flower. An iris blossom is to a magnolia flower what a computer is to an abacus.

This week at www.backyardnature.net/fl_iris.htm I've added a new page describing the special structures of iris blossoms. On that page you can see that the typical iris flower bears nine fleshy, colorful parts. The lowest three, which serve as landing pads for pollinators, are known as FALLS, the uppermost three are petal-like STANDARDS, and the three slender, arching segments at intermediate level are known as STYLE ARMS.

The style arms are the most interesting. That's because they are actually modified styles -- a part of the blossom's female sex organ. Remember, the male sex germ arrives at a blossom inside a pollen grain. The pollen lands on the flower's stigma, where it germinates and sends a pollen tube down through the STYLE, into the blossom's ovary, where the male sex germ unites with the female sex germ in the ovule. Later the ovule becomes a seed and the ovary becomes a fruit. You can review all this and see diagrams at www.backyardnature.net/fl_stand.htm

So, style arms are part of the structure holding the stigma, and in fact if you lift up an iris's style arm you can see a "stigmatic lip" forming something like an upper row of pale teeth beneath which the pollinator must squeeze in order to get inside the flower, to the nectar. As the pollinator passes the stigmatic lip, pollen scrapes from its body onto the lip, where the grains germinate and send their tube down through the style arm to the ovary. On my new iris page, you can see this stigmatic lip.

It's especially interesting to know about that stigmatic lip if you'd like to try your hand at hybridizing irises. You'd need to deposit the pollen from one iris variety onto the stigmatic lip of another variety. You might enjoy looking at the page called "Try Your Hand at Hybridizing with Irises" at www.taunton.com/finegardening/pages/bg0002.asp

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COOL ELEPHANT EARS
Between Wednesday of last week and Wednesday of this week we received 11.5 inches of rain (29 cm). This Wednesday finally blue sky broke through, the air above the sodden ground grew hot and steamy, mosquitoes and flies began biting, and sunlight on skin bore down in a manner decidedly Mississippish.

In Wednesday afternoon's glare, with sweat streaming down my face, I was attracted to the dark greenness of my fast-growing Elephant Ear leaves. It occurred to me that if I should touch a sunlit lawnchair constructed of metal of a thickness and dark color similar to the Elephant Ear's blade, it would scorch my skin. Yet when I touched the broad, flat Elephant Ear leaf facing squarely into the sunlight, it felt cool. Then I walked into the forest, and it also felt cool.

The main reason plant leaves remain cool despite being dark and sunlit is that they are constantly evaporating water in a process known as transpiration. Water changing from a liquid to a vapor state is an energy-absorbing, or endothermic, process, as anyone knows who has felt the coolness resulting from a breeze evaporating sweat.

In the middle of an average day, each hour an average land plant transpires around half a cup of water per square yard of leaf surface -- an area about the size of a large Elephant Ear. An average corn plant transpires more than 2 quarts (2 liters) of water each day. Most of this water exits the leaf through microscopic pores in the leaf called stomates. The bottom of an average oak leaf bears about 375,000 stomates per square inch (58,000 per square cm). Consequently, at 95°F (35°C), the temperature of an average leaf in full sunlight is about 88°F (31°C).

When we convert vegetative areas to pavement and buildings, the local ecosystem is shocked by much more than a loss of diversity. We can glimpse how severe that shock is by simply walking from the cool, welcome placidness of the forest into suffocating, mid- afternoon, manmade glare and heat.

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SUSTAINABLE ROCK & ROLL
Not since I was a kid in rural Kentucky listening on my transistor radio to pre-Elvis rock on constantly fading WLS Radio out of Chicago have I been interested in pop music. By the time I got to college during the 60s, my taste was solidly classical.

Still, most of my life has been conducted in the spirit of rock and roll. During my late 30s and all of my 40s I traveled almost constantly, eventually doing freelance writing, photography, artwork and botanical work in about 40 countries. I did it all on the cheap, winging it, living out of backpacks and making barely enough money to pay for gasoline, jet and bus tickets, Eurrail Passes, and an awful lot of cheap oatmeal. Sometimes I must have looked pretty scroungy as I banged into things, took chances, and generally felt like a Viking exploring the New World.

I'm saying this because I've come to a conclusion that might seem out of character for the sedentary hermit Newsletter subscribers know. Here it is:

We need to rescue the Earth in the spirit of rock and roll.

In the same dynamic spirit with which a nice suburban kid shakes off the conservative, easy-going, complacent attitudes of his or her family, gets an eyelid pierced and starts a rock band, we need to give a razz to this stockmarket and mall-walking world, the double-talking politicians and preachers, and rely on our own intuitions about what's right, what's real, and what we need to do about it.

It's clear that our current governing and administrative structures are controlled by powerful vested interests for whom discretionary wars and environmental destruction are prime tools. Corporations, a few rich, well-connected families and good-ol'-boy networks call the tune now.

The way to deal with this is to become clear in our own minds about which communities we should belong to -- communities no longer defined by geographical boundaries but by belief systems held in common -- and to become invisible to those who would manipulate us to their own advantage. Drop out, and tune in to the wisdom the Creator has put inside each of us, and written into the manner of being of the Universe at large.

The spirit of rock-and-roll can save us. And I am confident that the new wave that's coming will recognize intuitively that the ultimate rock star is the Creator of the Universe, that the Four Commandments are to love and cherish earth, water, air and fire (life is fire), and that sustainability is the main melody for anyone wanting the beat to go on.