September 14, 2006

A SHIFT IN BIRD MOODS
At noon on the day I type this I don't hear a single bird. Crickets and a miscellany of other stridulating Orthoptera do state their cases, but their callings are almost reflective and downbeat compared to the rambunctious singing heard earlier this spring and summer.

Just a month ago at this hour I'd have heard Field Sparrows, Indigo Buntings, House Finches, Yellow- billed Cuckoos and Yellow-breasted Chats defending their territories with song, and Chimney Swifts would have continually circled the old house calling down their twitterings. Now they are all silent.

The birds are still here. They slink among shadows and dart between sheltering interiors of scattered trees, and I know why they are so shy. Many are young birds experiencing their first late summer, still wide-eyed and nervous about life in general, not yet afflicted with sex hormones and recognizing no other imperative than to avoid danger and to eat, explore, and eat some more. Adults who've survived a whole nesting season are slinking, too. Many are molting. Turkey Vultures soar overhead with important primaries missing in their silhouetted wings. Molting birds can't fly as well as usual so they're more vulnerable to predators and it's best for them to keep low profiles. In fact, at this season, what's the point to attracting attention to yourself at all?

Occasionally, especially in late afternoon, I do hear birds, but what they say and how they say it conveys to my ears a completely different feeling than what we had not long ago.

In the big Blacklocust snag where earlier young Purple Martins stretched, preened and airily cheeped and chortled, now 45-60 young, chunky, bear-like Starlings occasionally show up gawking around and snarling their low-key jive into the sunlight. Sometimes more diffuse flocks of Robins filter through the area. One day the big Hackberry next to the house was loaded with purplish, pea-sized fruits, then a big flock of Robins came through filling the tree with so many flutterings and rustlings that it sounded like a little waterfall, and then the next day the tree was almost picked clean.

On certain afternoons one kind of juvenile flock leaves me scratching my head. Nowadays it's typical for afternoon storms to build on the horizon, thunder and possibly even bring rain before dusk. During dusks when storm clouds are just breaking up but drizzle still may be falling, sometimes low- slanting sunlight shoots between mushrooming clouds charging the drizzle with golden light, and then loose flocks of young Nighthawks are likely to materialize, like big, lumbering, silent bats. Maybe a dozen will fly around not really flocking together but keeping close enough to one another to know that the others are there, and they don't dive or make a sound, just heavily and mutely beat their way through the sun-rain.

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COCKLEBUR FLY BENEATH THE CRABAPPLE TREE
All summer a certain ornamental crabapple tree has stood before the old farmhouse as retiringly and unnoteworthily as a mouse in a kitchen. When the tree lost nearly all its leaves suddenly it became a poetic system of gnarly, black stems heavy with bright red crabapples. A painting of this tree using nothing but black and red pigments would be appropriate on any T'ang Dynasty urn. Sometimes in late afternoon I read beneath that crabapple just to glow in its dignity.

Of course a human in an animal body never can enjoy dignity for long because the body always ends up developing pains, getting stiff, needing to fart, or something. That day it was the sweating that led to this story.

For, a certain tickling developed on my leg and when I looked at the tickler it turned out to be a kind of sweat-sopping Diptera -- a fly -- I'd seldom seen. With calico-patterned wings, yellow head and thorax, iridescently green eyes, and a length of 3/16 inch (4 mm), it was one of the prettiest flies I'd ever set eyes on. You can see one yourself at http://www.cirrusimage.com/Fly_Fruit_Euaresta.htm.

Its intricately patterned wings, general body shape and the curious way it twisted its wings as it supped my sweat cued me to the fact that this was some kind of fruit fly, though not THE Fruit Fly, Drosophila, used so frequently in genetic studies.

Therefore, my next step was to use the Google image- search feature on the keyword "Tephritidae," which is the insect family to which fruit flies belong. Google came up with hundreds of fruit-fly thumbnail pictures and eventually I spotted my exact leg-licker. It was EUARESTA AEQUALIS. One website provided an English name for it, which was "Cocklebur Fly." That site was in Australia and it said that the fly's larvae live in cocklebur seeds, and for that reason the fly has been introduced into that country for control of the cocklebur weed.

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ROVE BEETLES IN THE COMPOST HEAP
I first mentioned Rove Beetles in my "Life in A Magnolia Blossom" essay of May 25, 2003. Down in the dewy zone beneath a magnolia blossom's bouquet of stamens where old stamens had fallen and now were turning brown and mushy, "Tiny, black, slender insects, maybe 1/8th of an inch long (3 mm), with strangely flexible abdomens segmented like cars on a kid's toy train skitter about... " Similar rove beetles populate my compost heap here, for that's another source of brown, mushy stuff, and you can see what they look like characteristically chewing on a maggot at http://entomology.unl.edu/images/beneficials/beetles/rovebtls.jpg.

About 3000 rove beetle species occur just in the US, and many are common. Happily, the group is fairly easy to identify because of a very curious, relatively obvious anatomical feature: Rove beetles' forewings are so short that they expose three to six abdominal segments. You can see this clearly at the above link.

The thing to keep in mind is that beetles (members of the insect order Coleoptera) bear two PAIRS of wings, thus four wings. Usually a beetle's forewings are hard like thick plastic, and often colorful. Think of a Japanese Beetle's rigid, shiny carapace, or a ladybug's. A beetle's hindwings are more like clear cellophane, like a fly's wings. In beetles, the hard forewings protect the delicate hindwings. When flying, the stiff forewings basically get in the way. Still, the hard-forewings-protecting-the-flimsy-hindwings strategy must be a good one overall, since Coleoptera is the world's largest insect order.

When you see how stubby rove beetle forewings are it's hard to imagine how the insects can fly. However, they are good fliers. The secret is that the cellophane- like hindwings fold up beneath the hard forewings.

Some of the longer, more slender rove beetles tend to curl up their rear-ends in a disconcertingly scorpion- like fashion. However, rove beetles don't sting. A few do have mandibles with which they can bite, but the ones I'm finding in magnolia blossoms and compost bins are perfectly harmless.

You can see examples of other kinds of rove beetles and read an awful lot about the group in general at http://creatures.ifas.ufl.edu/misc/beetles/fl_rove_beetles.htm.

*****

"PHORETIC" MITES RIDING DADDY LONGLEGS?
Probably you've seen that the legs of Daddy Longlegs -- those big, long-legged, spider-like critters also called harvestmen -- often have tiny, brightly red, tick-like creatures hanging on them. I've always assumed that these were parasitic mites. This week when a big Daddy Longlegs came lumbering across my floor bearing several crimson passengers I decided that the time had come to study the matter.

It turns out that this commonly observed situation is as yet something of a mystery to science! The mystery is whether the mites on the legs are really parasitic, thus stealing nourishment from the longlegs, or are simply hitching rides with no detriment to their host. The fine word describing a creature hanging on just for the ride is "phoretic," based on the Greek root "phoros" meaning "to bear."

The University of Kentucky provides a fine webpage at http://www.uky.edu/Ag/CritterFiles/casefile/relatives/daddy/daddy.htm telling all about daddy longlegs. About two-thirds down that page you can see red mites hanging onto a longlegs' legs.

That page also passes along some funny superstitions relating to daddy longlegs. For example:

Another myth from the old days said that if you killed a daddy-longlegs it would rain the next day.

A couple of years ago a modern "urban myth" emerged about daddy longlegs. That one claimed that daddy longlegs are the most poisonous spiders in the world, but their fangs are so short that they can't bite a human. In fact, daddy longlegs are not spiders at all, but their own thing, and they don't even possess venom glands.

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CYCLOSA CONICA SPIDER
Being hypoglycemic and profoundly myopic (When I walk down streets, lampposts bend into Cs as I pass because of my lenses' severe concavities) I'm accustomed to my visual world unexpectedly twinkling, wobbling, and twisting out of shape. Therefore the other day when the air before my face developed a dark, violently jiggling smudge I only imagined that I needed more sugar in my bloodstream.

However, when I turned my head the dark smudge didn't follow my line of vision. Therefore this jiggling thing suspended in mid air was real, and I needed to take a closer look.

What a pleasure when I finally got the little being in focus. Suddenly I was recalled to a late summer day forty years ago on our western Kentucky farm. From the white-painted mailbox on our dusty gravel road, 18- year-old me had just retrieved a package containing a book called "The Common Spiders of the United States" by James H. Emerton. Back then today's fieldguide- publishing industry hadn't yet been born, so I'd begun haphazardly amassing a library to help me identify and understand my local plants and animals.

My library-building strategy consisted of ordering inexpensive paperback reprints of natural-history classics from Dover Publications in New York. Emerton's book, a reprint of a 1902 classic, was my first acquisition for the envisaged library. It bore black-and-white line drawings and black-and-white, blotchy photographs. Compared with today's fieldguides it wasn't much, but it was a beginning.

Now for the first time in my life I walked afield aiming to identify something using a book. Before then I'd identified some birds using pictures from a Lady's Home Journal magazine, but that was kid's stuff. Now I was serious. Now my life as a real naturalist was beginning, maybe.

After several failed attempts and some hours of growing frustration, finally I encountered a spider so curious that surely it would be included in Emerton's book. For one thing, its abdomen bore a conspicuous, rounded hump like a lady's bun. Even more curious was that the spider arranged its preys' sucked-dry, brown husks and its own brownish egg-cocoons into a vertical line oriented through the orb-web's center. And, MOST remarkable, was that when I got too close to this spider, which was camouflaged as part of the vertical debris line, the spider violently jiggled the web causing the line to shake crazily enough to surprise or disorient any bird or wasp who might be out spider- foraging.

Sure enough I was able to make my very first book- based field identification of any organism. I had come across a CYCLOSA CONICA spider, apparently with no common English name. Possibly this was also the first scientific name I ever learned for any organism. You can see Cyclosa conica, its debris line and its web at http://www.nicksspiders.com/nicksspiders/cyclosaconica.htm.

On the margin of the Cyclosa conica page in Emerton's book, with a ballpoint pen I inked in the following still-visible, sparse but first-ever-for-me field note: "Newground 8-20-66."

"Newground" was the name for that part of the farm most recently opened to cultivation by cutting and burning the trees, and pulling out the stumps. When it rained in 1966 the Newground's soil still reeked of sulfurous swamp-mud and ashes.

What a pleasure this week to see that after forty seasons of hard winters, habitat loss and plenty of hungry birds and wasps, Cyclosa conicas still jiggle their webs exactly as they did back in the summer of 1966.

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STIPULAR SHEATHS
Wherever the ground stays moist to wet, as down around the mint-spring, nowadays there's a delicate-looking, herbaceous plant topped with nodding, slender spikes of white flowers. Some books call it Water-pepper. It's POLYGONUM HYDROPIPEROIDES of the Smartweed Family. Water-pepper is closely related to the weedy Smartweed, which has thicker, shorter spikes of pink flowers. You can see Water-pepper here.

The Smartweed Family has a special feature enabling beginning botany students to recognize it without having to look closely at tiny flower details. That is, at stem nodes -- where the leaves attach -- members of this family bear "stipular sheaths." This week I added a picture of a Water-pepper's stipular sheath to my website's Stem Page, and you can see that at https://www.backyardnature.net/pix/stipshth.jpg.

The stipular sheath in my new picture shows up as a brownish, cellophane-like membrane surrounding the stem above the thickened node. It's shaped like a cylinder with obscure, vertical, parallel veins. Nearly all members of the Smartweed Family bear such sheaths, but few other plants have them, at least when the plants are fully developed.

Stipules serve as thin coats protecting stems, leaves and flowers as they emerge from their embryonic states. Many other kinds of plants do produce stipules, but either the stipules fall off soon after they're no longer needed, or else they are no more than tiny, inconspicuous, ear-like flaps. Scars of early-falling-off stipular sheaths ring the stems of magnolias, Yellow-poplars and Sycamores. At the base of oak-tree buds usually you can see tiny, straight scars where small stipules were present earlier in the year. Another of my pictures shows stipules and stipule scars on a Sycamore twig at https://www.backyardnature.net/pix/stipring.jpg.

You can see broad, floppy stipules on a Yellow Poplar twig just before they fall off at https://www.backyardnature.net/pix/stipules.jpg.

Stipules are one of those things most people never hear of, yet they are important to many plants and, if you know about them, they can help you identify your plants.

*****

IS EXTREMISM NATURAL?
To keep up my German I regularly listen to German programs on shortwave. Lately the big news in Germany has been the Pope's visit to Bavaria. It was reported that the Pope's central message was that people should stop abandoning Jesus Christ for atheism.

Framing the message like this -- suggesting that people are choosing EITHER Jesus OR atheism -- establishes in the listener's mind a false dichotomy. The effect is to deflect recognition away from the rainbow of spiritual options people have other than Christianity and atheism.

False dichotomies constitute a subtle but very powerful rhetorical technique that distort reality without requiring outright lying. George Bush uses one when talking about terrorism. "You're either with us or you're against us" he says, ignoring the option most of humanity chooses, which is neither to support terrorism nor to wage war in Iraq and curtail domestic civil rights.

One has to wonder why powerful, well-informed people so consistently rely on this trick.

Of course the answer is that it works. We have seen that humanity's en-masse behavior is shaped by whatever simple concepts can be processed by the reptilian brain perched atop each of our human spinal columns. A "them or us" world responding to real or imagined fear is something our reptilian brains can deal with.

This brings up an interesting question: How does Nature look upon demagoguery and the kind of extremism demagoguery usually serves? Walking the fields this week, that's a question I've been thinking about.

What I decided was that Nature expresses many extreme points of view. There are fish where males become tiny parasites permanently attached to the females, serving only to produce sperm upon demand. There are creatures able to survive only in almost-boiling, highly sulfurous waters next to ocean vents. Species of many kinds have habitat requirements so precise and unusual that the species themselves occur only in a very limited area. Giraffes and rhinoceroses, algal cells and fungal hyphae capable of living alone mingling to form lichens, viruses that most scientists agree aren't even living things... Everyplace you look Nature pushes concepts to such extremes that -- if you believe that "Nature is Bible" -- you have to suspect that even in human society extremism must have its place.

And yet, most of the things of nature are not as outlandish as giraffes and lichens. The forest here is mainly home to run-of-the-mill oak and hickory trees, mushrooms that neither kill you nor taste heavenly, and chemical processes that can be reproduced in any good lab. Ordinary things and processes following a Middle Path are what most make forests and fields stable, sustainable and beautiful. Yet, it seems that all complex systems do support a few extreme elements.

Therefore, my opinion is that we humans would do well to honor the Middle Path as indicated by forest and field. However, in order to know where the Middle Path lies, we must be able to distinguish what's normal from what claims to be normal, but actually is dangerously extreme.

*****

Best wishes to all Newsletter subscribers,

Jim