Naturespeak A naturalist's view of the world

September 8, 2007

AAA Spider

Filed under: Uncategorized — wykes @ 9:41 pm

 When the mere maiden Arachne bested Athena in a Grecian weaving contest, she paid a terrible price. Athena was a goddess, after all, and those types don’t like being humbled. Unequipped with Star Wars wisdom (letting the Wookie win so that your arm remains in its socket), Arachne forged on and boldly won the day.  Later she suffered a severe Wookie thrashing and her pleasing features were mangled for life by Athena.  Although the other gods living on Deity Blvd. eventually took pity on her, they waited until she died to honor her with the role of weaver goddess.

  In the modern world, we know all hideous faced weavers as followers of Arachne and call them Arachnids: the spiders.  Never mind the fact that spiders have been on the earth for millions of years before there even was a Greece or an Arachne,  they inspire us to spin tales as fast as they spin their webs.  Consider the Banded Garden Spider, that spider of the season that produces those stunning orb webs along the field path.  Here is a large spider that elicits wonder even in those who normally get sweaty and make infantile noises around such beasts.

  I won’t shower you with photos this time.  Just take a look here and you’ll see the arachnid to which I refer.  She is a beautiful thing perched upside-down upon her carefully crafted website. This one just completed the process of turning a newly caught grasshopper into a burrito by wrapping it within a silk blanket and was about to deliver the coup de grace when I bumbled upon her.  She shyly abandoned her catch and dropped to the lower section of web in order to hide her face, but soon regained confidence and returned to her meal. 

  The Banded Garden Spider is a member of a select group of orb weavers known as the Argiopes.  They are the best of the best in a weaver’s world. Though their structures are only meant to ensnare insect prey, their simplicity of design seems divine (sorry Athena, but its true).  The radiating spoke of the web is made with non-sticky threads and the spiraling portion with sticky fibers of high performance liquid protein.  The center of the wheel is reserved for the huntress to await her prey.  She remains in contact with every spoke and instantly detects if an insect gets ensnared. You’ll see that her legs are held out in the fashion of a St. Andrew’s cross and paired in sets of two.  Our garden spider, though possessed with eight eyes, has poor vision so she relies strictly on touch.

  Often Argiopes create elaborate zigzag patterns down the center of their web as a finishing touch. This trait has earned them the name of “writing spiders,” even though their penmanship skills are limited to repetitious Z’s and W’s.  The real reason behind this behavior is believed to be the equivalent of us putting stickers on our porch windows to keep birds from crashing into them.  If a bird should blinder through one of these webs it is both destroyed and eliminated.  Argiopes eat their old silk in order to recycle the proteins into new silk. The loss of a web creates an additional workload, so the Z’s spell “Yield.”

  I came across one odd superstition about this web writing thing.  It is considered bad luck to mention the name of a loved one while standing next to an orb web.  The spider will hear it and incorporate it into its next web. This is apparently a bad thing.  Obviously, these folks have not read Charlotte’s Web (“Some Pig”).

  The web supporting the female in our picture had no such writing on it, so I could concentrate instead on her lovely features alone.  Her plump abdomen was delicately banded with black, white, and yellow striations – thus her common name.  The head shield area on the back of the beastess, was creamy white with a silvery hue – thus the reason for the Argiope name.  You see, Argiope was another one of those immortal Grecian entities.  She was a Naiad Nymph who lived on the slope of Mount Parnassos in Phokis. Her name is translated as “of the silver face” since she lived in a silvery mountain stream.

  Nymphs, like Argiope, were divine nurses of the young and protectors of girls and maidens. Arachne could have used one of these!  They saw it as their duty to insure that their charges safely navigated the perils of youth and attained adulthood.  Perhaps here is the best correlation between the water nymphs and the water-phobic spiders.  The life of an Argiope spider female is dedicated to getting her next generation through the perils of winter.

  The males certainly play a role in this game, but they are less than one third the size of the females and are rarely seen. By the end of summer, the females will construct a tough papery egg sac, shaped like a kettledrum, and place it along the edge of the web.  Just like Charlotte, she then dies.

  Safe inside the package she has provided them, hundreds of her yellow eggs – looking for all the world like tiny egg yolks sitting in cupcake holders – will remain safe until the following spring.  Most of them hatch before winter’s blast, but all remain inside until the proper time.

  The autumn Argiope is a lady on her last legs, but one nearing completion of a divine task.

September 6, 2007

Going for Burr Oak

Filed under: Uncategorized — wykes @ 9:15 pm

 Golden September mornings and Burr Oaks go together like fine cheese and dry wine.  Both the tree and the time of year are best viewed through the crisp light of a new risen sun.  Although your free background music will be supplied by a chorus of crickets, your mind should summon up something more stately or complex- like a Bach piece- in order to complete the September scene.

  I ventured under the cover of one of these stately trees and found my thoughts taking the form of a pseudo Shakespearean soliloquy. I have no idea why, since I wasn’t wearing tights. “Now here is an Oak,” I pondered.  “Witness how it patiently supports its leafy exuberance with knurled frame and holds silent a deep wisdom wrought of the ages.  One by one she yields her mossycup seeds of wisdom to the wiles of the wind and scurrying rodent. Nary a nut will fall from her bosom that she does not mourn.”  Why Shakespeare and why Bach?  It’s just a tree for goodness sake.  Ah, but what a tree.

  Oaks rightly stand as symbols of strength and longevity. The Burr Oak is a champion among its kind. In early life it is among the fastest growing of the oak clan.  At the other end of the spectrum it achieves the greatest longevity of the bunch– over four centuries.  Throughout life these robust upland trees produce the largest of all acorns.  Each nut is capped off by a spectacular fringed cap which is responsible for the alternate names of mossycup or overcup oak. Now here is an oak.

  Neither J.S. Bach nor the Bard ever caught sight of a Burr Oak in their lifetimes, since it is an exclusive resident of the American Midwest and they remained on the other side of the pond.  Bach was a Burr-oak period composer, however…….oh, wait a minute, that’s Boroque – not Burr-oak.  Sorry.  Well, there are some Burr Oaks still around that began life during Bach’s lifetime.   

  Since Willie S. did know Latin, he would have known what Quercus macrocarpa means. He would have translated it as “The oak with the big seeds” but could not have said that he knew it well. There is absolutely nothing linking Bill Shakespeare to the tree, that’s just a neuron twitch in my own brain. Sorry about that one too. 

  O.K., let’s forget this course of discussion and take a look here to see what I’m talking about.  Here is a branchlet exhibiting two distinctive Burr Oak traits- big lobes and big acorns.  As a member of a group of oaks called the “white oaks, the Burr has leaves with rounded lobes. The outer portion of the leaf expands into a broad surface with shallow lobes while the inner portion of the leaf has deeply cut lobes. The acorns, the “macrocarpa” part, possess the aforementioned fringe caps topping a stout nut of about 1 inch dimension. 

  Let’s ponder that magnificent nut.  Burr Oaks begin to produce an annual crop of acorns beginning in their third decade of life. They reach their peak of production between the tender years of 75 and 150 and begin a slow decline in production over the next century or two or three.

Typical of the white oak family, the acorns mature over the course of one season and begin their earthly journey in September. 

  Larger squirrels like fox and gray squirrels often hasten this descent by cutting the nuts down.  Once on the ground they compete with deer, deer mice, and turkeys for the right to eat them. Weevils and all sort of micro life insure that most of the seeds never sprout. In part due to this heavy pressure, oaks tend to vary their acorn production from year to year. They will produce a heavy crop every 2 or 3 years and then follow it with a year of no production.  This tactic keeps the acorn eaters off guard and forces them to move around a bit.

  Such a long range seed bearing plan seems above the thinking capacity a dumb chunk of wood doesn’t it?  Maybe those mossycup acorns are seeds of wisdom afterall, but that just can’t be.  No way.  Perhaps I doth protest too much?

  NOTE: Take a look here of my newly drawn sketch, done in an old-fashioned manner, of the leaves and acorn of a Burr Oak. This is what happens when you listen to Bach.

September 4, 2007

Dog Day Afternoon

Filed under: Uncategorized — wykes @ 10:25 pm

You can actually hear the end of summer if you listen closely.  As August fades into September and we creep further into the month you’ll notice that something is missing, although it may not be dramatic.  Often we loose ourselves in the bustle of the season as kids return to school, politicians crank up their rhetoric, and disorganized groups once again become organized.  By the time we look up, the cicadas are gone. 

  Few people need to be introduced to the cicada. Although they may not be familiar with it by sight, they instantly raise eyebrows in recognition upon hearing their call.  Cicadas are those loud “buzz” bugs that fill the sultry late summer air. Their ear shattering mechanical rasping call is one of those quintessential sounds that define a season.  Cicadas do their thing during the hottest time of the year and are a good measure of the yearly cycle. Now that their time is waning, it’s a good time to stop and appreciate them before their time is up. 

  Yesterday I encountered one of these songsters.  Pictured (here and here) is a nice example of a species known as the Dog Day Cicada – at least I think it is. There are 155 kinds of these insects, so I have to admit that it could be a Linne’s Cicada.  Both are common in our area and both look pretty much alike. Sometimes, it just doesn’t really matter. When I am old and gray I will take the time to count tymbal ridges and measure wing angles, but for now let’s just pick one name and be darned with the consequences. I especially like the name of the Dog Day Cicada, so that’s what I’ll call it. The name refers to the “Dog Days of Summer” when it is most active. The Dog Days get their name from Sirius, the Dog Star, which is visible in the late summer constellation Canis major. Siriusly! This far more interesting than Mr. Linne’s bug.

  One thing that emerges from a close examination of these extraordinary bugs (and they are “true bugs”) is how beautifully made they are.  I would not be the first to recognize this fact.  Jewelers, especially in the Orient, have long depicted cicadas in all manner of elegant stone, ivory and precious metals. Take a look here at this magnificent modern design by Korean designer Wallace Chan and you’ll swear it will fly away.  Don’t swear, however, just gasp.

  Most of our regional jewels emerge annually.  The nymphs emerge out of the soil after a year or two of root sucking. They climb up the nearest tree and shed their skin to become flying insects.  The empty nymphal skins last long after the bugs that emerged from them are gone (see here). There is always a new generation coming out of the soil every season, although they are staggered.  

  Periodical cicadas emerge once every 17 years. There was a hatch this year in S.W. Michigan, but I missed it. The next time we’ll be able to get together to see these old timers in our area will not be until 2021 or 2024.  By that time I will be busy with tymbal ridges and wing angles, although my eyesight will probably be shot.  An annual cicada, such as my example, will do just fine.

  All cicadas have a car grill for a face (see here).  In fact they look very much like an Edsel or something of that vintage.  You’ll also notice that long piercing beak for sucking tree sap – a habit they do not shed with their last skin. Those of you that remember Edsels, by the way, are probably already old and gray and might be contemplating some tymbal ridge research. Maybe I should explain my fixation with that terminology, lest I lead you astray.

  Cicadas have achieved the level of “the world’s loudest insect” by their sheer instrumental prowess. The males “sing” by using two ridged organs – membranes really – called Tymbals.  These membranes are located under the wings on the first segment of the abdomen.  By counting the number of ridges (usually 8 or so) you can tell species apart, but you can do the same thing by listening to the distinctive drumming calls produced by those membranes. Each species has a slightly different version of “Wipeout.”

  The sound is produced by popping the tymbals in and out.  Superfast muscles attached to the center of each drum act to pull them in and allow them to pop back out as much as 50 times per second!  Since a goodly portion of the abdomen is hollow, the effect is resonated to ear-splitting intensity. Take a look at this diagram and I think it will help you see this internal arrangement. The caller can even increase or decrease the intensity of the call by opening a pair of flaps called operculums.

  It is worth noting that the term “superfast” is not mine, but a term used by researchers who are studying cicada muscles.  They are attempting to learn how these tiny fibers can achieve a pull reaction fully 50 times faster than our muscles and how they do it without tiring.  If their research pans out into a usable human application, I might be able to do more than one push up per minute.

  As a general rule, any animal that is a good talker is usually a good listener as well. Male cicadas use all this tympanal energy to attract females. The females do not talk, but instead concentrate on listening skills. They detect the love drum melody through a pair of smooth tympana close to the wing pits.

  As a human male, I find it singularly amazing that there are some females out there that listen more than they talk, but will not pursue that angle of thought.  I will, however, leave you with a fascinating feature of the male cicada.  Males, you see, also have big ears.  They need them in order to pick up rival calls.  How is it, then, that loud mouthed males don’t make themselves deaf?  They lose their ability to hear when they are talking.

  Yes, when a male cicada begins his call (a 15 second buzz saw, in the case of the Dog Day Cicada) the tympana become creased and so they can’t hear themselves.  I’m not so sure that’s an exclusively cicada trait, guys. 

  I’m sorry, I didn’t hear what you said?

September 2, 2007

In a Bind

Filed under: Uncategorized — wykes @ 9:05 pm

  Climbing vines go about their business in plant time – slowly and methodically making their way to get a piece of open sky.  In time lapse photography they appear to blindly seek their position with random motions before securing their hold. Their stems appear thin and weak, but are instead lithe and sinewy like a rock climber’s arms. Their efforts are calculated and goal driven. They seek audience with the sun. We interrupt them in our time and can only see their determined effort as a freeze frame or a snap shot.  I have a few stills to show you of one of the prettiest faces in the climbing vine bunch: the Field Bindweed.

  The bindweed is indeed a handsome plant.  Take a look here at one of the delicate pink funnel blooms of this common late summer bloomer.  At first glance, the gardeners among you will notice how closely it resembles the domestic Morning Glory (those wonderful tendrils which wrap around rural mailboxes and porch rails).  That resemblance is more that incidental.  Both the field plant and the domestic one are in the so-called Morning Glory Family.  You might be interested to know that the Sweet Potato is part of the family clan as well.

  The sinewy wild plant, in fact, comes from Eurasia where the many varieties of cultured Morning Glory hail.  It arrived here as an ornamental in the early 1800’s but was shunned as a feral “weed” by the end of the century.  Nobody plants them on purpose anymore, but they still inhabit the fringes of our living space like lonely orphans. In a weird sort of way this is like shunning the runner-ups on American Idol.  Remember, we brought them here to start with. In the long run, like any good competitor, they can withstand about anything we throw at them.

  Names like Small Flowered Morning Glory and Creeping Jenny are a few of the innocuous alternate names that we throw at them, but the term Possession Vine certainly indicates a negative trait.  Like tough street orphans they climb all over lesser plants to gain the advantage of altitude. In a wild setting they have a harder time dominating their fellow plants and therefore are easier to enjoy.

  Stop to take a sniff of the delicate bloom and notice the sweet vanilla scent and your enjoyment level will increase.  The flower is made up of five petals, but they are fused together to form a continuous pink funnel called a corolla. True to their family name, they open up select blossoms just after the sun rises and close them up at sunset.  Sometimes they retire early on cloudy days when Old Sol is bashful.  The flowers track the sun when it is out – a behavior which is termed Heliotropism. Oddly enough, all that flowering energy usually goes for naught and individual plants often fail to set seeds.  These determined climbers carry on over the generations by sprouting exploratory stems from their rhizomes.

  Their universal name Convolvulus arvensis means “plant of the field that entwines” and that is just what they do. Possessed of small leaves, it is important for the plants to gain open sun to carry on the business of photosynthesis. Take a look here at one of the vine sections and you’ll see how it is wrapped multiple times around a cat-tail leaf.  What you may not have noticed is that the stem rotation is counter-clockwise around the cat-tail.  You could say that Bindweeds are always left handed, except that they don’t have hands.  Let’s just say they are left spiraled and leave it alone.

  The growing tip of the vine is able to complete a rotation in about two hours according to one source.  That is almost in the range of human observation time.  Who knows, watching the bindweed grow may catch on as a sport to rival corn and grass watching and we’ll stop persecuting it.  Instead of super slow motion capture of a baseball swing, we’d need to set up one of those time lapse cameras to see what’s really going on.

  As I mentioned before, the plant rotates as it extends upward. This motion insures that contact with the nearest surface – a cat-tail leaf or a fence post – is maintained.  As long as the inner surface is there to climb, the plant senses it and sends out growth hormones to the opposite side of the stem.  In this manner, the outer part of the vine grows faster than the inner portion and it spirals up to the gloryland.  Maybe I’m being a bit dramatic here, but somebody has to speak up for a lowly “weed.”

« Newer Posts

Powered by WordPress