Naturespeak A naturalist's view of the world

October 29, 2009

A Beetle to Die For

Filed under: Uncategorized — wykes @ 8:40 pm

I doubt that any kids out there will be dressing up as a Predaceous Diving Beetle this Halloween. Apart from the obvious structural difficulties it poses as a costume, it is too obscure of a beast to qualify. And the name, well, that name is just not catchy enough. Albeit descriptive, it’s just a little too generic –  like calling a Tyrannosaurus rex a “Predaceous Walking Sauropod” or a Grizzly Bear just a “Large Bear.” These creatures have a semantic zing that places them in the spotlight as bad boys – big bad boys. The Predaceous Diving Beetle is a bad boy too, but it can’t get the press it deserves with a name like that.

Granted, you don’t see too many Halloween T. rexs or G. bears out there pounding the trick or treat circuit, but 4 out of 5 boys would be proud to dress as one or the other if the opportunity presented itself. I doubt your regular  little Timmy or Rebecca would find it exciting to declare themselves as a Predaceous Diving Beetle when asked at the porch. “A What?’, the befuddled candy giver would remark after acknowledging the clearly identifiable princess, devil, and hobo next to you.  “I said, I am a Predace..ous..oh, never mind. I am Dytiscidae, Lord of Aquatania.”  I am not speaking from personal experience here, but I can imagine such an occurrence. I remember “treating” once in  a homemade Big Brown Bat costume and recall the frustration of being variously identified as a pile of rags, a mouse, and a cat’s hairball.

The Diving Beetle is a creature worthy of the name Dytiscidae Lord of Aquatania. Perhaps we should launch a campaign to change the name.  These hefty aquatic beetles (see one in hand above) are members of the family Dytiscidae (I said “dy-TIS-ki-dee”). True to name they are predators which feast upon lesser life forms in our local marshes and ponds. They rank among the top predators in the aquatic world and are lords of their domain. Everything, well almost everything,  about them is geared to predatory performance.

These beetles are equipped with hollow needle-like jaws (see portrait above). When they grab prey, digestive juices are quickly injected into the quarry whose pulpy remains are then slurped up. While grizzly bears dismantle their prey from the outside in, the Lords of Aquatania (I said “a-kwa-TAN-i-a”) take care of their business from the inside out! In basic outline, you will find no sleeker creature than the PDB (aka D-LoA). It is made to cut through the liquid element without offering any drag. Every body segment fits neatly with the adjacent part to offer a seamless profile. It is difficult enough to hold onto one of these things when they are dry, leave alone when they are wet.

Diving beetles take in a bubble of air under those sleek wing covers to serve as an aqualung. They are air-breathers. The oxygen supply is refreshed on a regular basis by surfacing for air with the back-end directed first. Tyrannosaurus, as far as we know, took in their air front end first.

Perhaps the most remarkable features on these beetles are the highly specialized legs (see a full set here). In most swimming beetles, the legs are fringed so that they can perform as paddles. Indeed, the last pair of legs on the PDB are heavily fringed. These paddle legs are employed in unison, like the action of a sculling team,  to propel the insect forward in no uncertain terms. The second pair of legs have a fringe as well, but are also covered with dozens of little suction cups to provide grip on slippery surfaces and prey (see above). Male diving beetles sport a set of amazing suction cup apparatus (apparati?) on their first pair of legs (see below and detail here). These structures, looking for all the world like glass-handling suction cups,  serve to maintain a grip on slippery girl diving beetles when they mate. You’ll note the two large suction discs and the multiple smaller suction points needed to keep the female from breaking away during “the act.”

I must admit, all these specialized parts would be impossible to duplicate on a Halloween outfit, but wouldn’t it be great to have a pair of those sucker disc feet in order to plow into that dish of Snickers – emptying it with one swipe. Why, those other “regular” kids would envy you – you, the Lord of the Treat bowl. Should you attempt to make a Water Lord costume for your kids, it would be wise not to divulge the real purpose of  those sucker cup things until your children are well past trick or treating age.

October 26, 2009

Leap’n Leopards

Filed under: Uncategorized — wykes @ 7:53 pm

Take a look at this passage from a research paper on Leopard Frogs (published in Brain Behav. Evol. 2004; Saltzman, Zacharatos, & Gruberg). Please read carefully – there will be a quiz.

“When given a choice between one large aperture…and three apertures of smaller but equal diameter they (Leopard Frogs) choose the larger diameter aperture …at a frequency that is statistically greater than chance.  In only 1 of 255 attempts was there a jump to the overhead cover that was not directed at an aperture.”

In other words, Leopard Frogs can aim. They may not have the need to jump through holes in nature, but the test proves that they are excellent judges of both distance and vertical space. This experiment simply verifies the well known  fact that frogs look before they leap. In this case, the amphibians consistently chose the larger hole as the most promising escape route. O.K., this is not an earth-shattering revelation but one worthy of consideration.  I recently took a video which essentially proves the same point as the above quoted experiment, but in a direct visual manner. Take a look at it here and we’ll talk about it.

Yes, you just saw a sequence showing a Leopard Frog deliberately, and expertly, ascending and descending a set of stairs. There were five steps in all. Each level rose 6 inches but they all were easily and quickly cleared. Each was also composed of unforgiving concrete – a missed step or faulty leap would have resulted in some skinned spots and some head trauma.

As if that wasn’t enough, you also may have noticed that the speckled creature carefully assessed the possibility of jumping the low brick wall that it encountered at the top of the steps. It viewed the situation  multiple times from multiple positions in order to get a good fix on the exact location of the lofty top edge of the wall in question (which is “only” about four feet high). You can see the internal head gears working as the jumper considers his next move. Deciding that such a leap was out of Leopard Frog faith limits, he turned and gracefully descended the steps and continued out across the grass toward the marsh. All in all, this was a great demonstration of frog smarts.

All of this, however,  might easily beg the question as to why this frog was jumping steps in the first place. Perhaps, you might ponder, I put him up to it just to get a cute video or that the frog was exhibiting stupidity rather than intelligence. Well, first of all, let me tell you that I didn’t put him up to it. If I was was going to set up a cute frog shot then perhaps a gambling scene with the frog shuffling tiny cards at a tiny table would have been worth it. No, I spotted the creature hopping through the grass and ran out to take his portrait  (see above). A few minutes later he was at the base of the steps and started climbing them before I could even get the “film rolling.” He took no direction or prompting from me.   Now, the stupidity thing – what about that?

Leopard Frogs, distinguished by there distinctive random spotting, are  among the most terrestrial of frogs. They spend more time in the wet grass of meadows and backyards than they do in ponds and marshes. Called “Meadow Frogs” by some because of this behavior trait, Leopards have been known to travel great distances from open water in search of insects, worms, and small invertebrates to eat (instead of walking a mile for a Camel they hop a mile for a Camelback Cricket!). During the fall, they characteristically make small overland migrations to select overwintering sites as the late fall season encroaches . This stair-stepping frog, therefore, was merely acting out its normal exploratory tendencies while on the way to a winter vacation spot.

Leopards are world class jumpers. One might even say they touch the realm of superpower in this regard. They are able to jump 13 times their body length in a single bound – a skill even Superman would envy. Heck, a super frog could eat a Spiderman for lunch. Leopard Frogs are destined for a simple earthly existence, however. They can’t leap small brick buildings in a single bound but they are able to take life one concrete step at a time.

October 22, 2009

You Go, Bear!

Filed under: Uncategorized — wykes @ 9:01 pm

Well, the official 2009-10 Woolly Bear Weather report is in.  Before you dismiss my results out of hand, allow me to explain that my research was performed under carefully controlled clinical conditions and made use of time-tested techniques. I do not take this task lightly. After-all, road commissions need to know how much salt to order and long underwear companies need to predict their upcoming sales. Our very lives depend on the accuracy of such a report. History has proven that the traditional methods of weather prognostication, such as measuring the thickness of the wall on a hornet’s nest, calibrating the bushiness of a squirrels tail, or judging the  intensity of pain emanating from a corn, are bogus. No, only Woolly Bear caterpillars should be considered as  long-term weather prophets. According to the accumulated wisdom of the Woolly bears, therefore, the 2009-10 Woolly Bear Winter Forecast Number is……….drum roll, please…….brrrrrrrrrrrrrrrrrrrap! 5.2!

Please allow me to explain the science behind this incredible figure. Don’t worry, I’ll simplify the complicated stuff and give it to you straight. In the ‘bearcast biz. 5.0 means average winter conditions – you know some snow, cold air, one dead sparrow, etc. Any number higher than 5.0 means above average winter conditions – like some more snow, a few more colder days, a small pile of dead sparrows, etc. The scale only goes up to 12, which would indicate a winter in which every single sparrow freezes to death. Numbers lower than 5.0. of course, point to balmier conditions with less snow, fewer cold days, and increasing numbers of sparrows dying from heat exhaustion. A “0” on the bearcast scale means massive flooding, brush fires, and windrows of tiny cooked sparrow carcasses lining the melted asphalt streets. Sparrows do not like the ‘bearcast for obvious reasons. At any rate, a number like 5.2 means “slightly colder than normal with a good chance of chilled sparrows.”

Woolly Bear Caterpillars, the fuzzy larvae of the Isabella Tiger Moth, know a thing or two about winter. They overwinter as larvae and finish their growth cycle the following spring. Their distinctive black and orange woolly coats serve to protect them from predators (they roll into a ball when threatened) and provide some insulation against chilly fall temperatures.  Your typical Woolly Bear is black at each end and orange in the middle, but individual ‘bears vary in the width of that orange band.  Long ago it was “discovered”, by people missing several teeth,  that wider orange bands foretold cold winters and narrow ones indicated warm winters. “Them that have them big orange sweaters,” it was widely reported, “are gitt’n ready for a right nasty winter.” Thus the source of the ‘bearcast tradition.

On a bright sunny afternoon not so long ago I decided to tally up an average of Woolly bear sweaters and see what they foretold. I simply counted the number of body segments bearing orange bristles and then averaged them out. There are a maximum of (about) 12 body segments per ‘pillar, so theoretically the counting could run from “o” up to “12”, but the actual range is between 4 and 6 (average of 5).  I examined 9 individuals which ranged from a low “normal” number of 4 to a high of 6 orange segments. Some segments were half covered and were recorded as such. The individual pictured above was a 6 bander  (go ahead and try your skills out). The population averaged exactly 5.2 orange segments – thus the winter forecast number.

Just for laughs, I also attempted to record the average speed of the caterpillars. Woolly Bears can really burn up the grass when they are clipping at top speed from one side of a field to another. According to my calculations they were moving at the rate of exactly .037 mph. I imagine that they could attain higher speeds if shaved and will attempt a future experiment once I figure out how to shave them (they have 16 armpits!).

Before you rush out to get those long undies, I feel the need to tell you one more thing. Although my data set consisted of 9 caterpillars, I actually encountered 10. I threw out the results of the tenth beast because it was abnormal and, besides, it would have skewed the results. This individual, pictured below, was all black. According to this one brush fires and charred sparrows are in our future. In other words, there would be no winter at all! I had a bad feeling about this bizarre individual. My sense was highlighted by the fact that it had a milkweed bug riding shotgun on it’s back. The little guy was holding on for dear life as it’s furry ride chugged across the trail. That was just plain strange. As far as I know, there are no folklore interpretations to cover such an un-natural partnership. If there is, I’m sure it would require the loss of a few more teeth and lives of a few more sparrows.

October 19, 2009

A Flight of Fancy Floss

Filed under: Uncategorized — wykes @ 8:16 pm

I wish Milkweed plants weren’t so dog-gone photogenic this time of year. I generally waste so much time admiring their artistic merits – you know those rustic pods spilling out cascading plumes of cotton – that I probably miss other more important elements of the autumn landscape. How many times did a Bigfoot cross the trail behind me as I was bending down to get “that perfect shot” of  a pair of milkweed parachutes intertwined on a branch?(Like this one).  What if that elusive S.E. Michigan Cougar wandered by as I was obsessively counting milkweed seeds and releasing them to the wind. How many front cover shots did I miss just because I was looking at an extremely common weed? Heck, what if that cougar  or some murderous Sasquatch  ever decided to sneak up on me as I was so engaged – what then, eh? Imagine the headlines – “Local Man Claims Bigfoot Attack – Has Only Blurred Milkweed Pictures to Prove It.”

O.K., you might see this all as a flight of fancy on my part, but consider yourself forewarned. Just because something hasn’t happened yet doesn’t mean that it won’t. But, as long as I’ve brought up the subject of milkweed seeds, I might as well continue with my observations and save you from undertaking  this potentially life-threatening activity. You can thank me later when you come up with that award-winning pic.

Milkweed pods erupt on sunny fall days in order to release their seeds to the wind. The plants produce four to six seed pods over the course of the growing season and raise them up from two to four feet off the ground in anticipation of this big flight. Laid up inside the pod like a pine cone (see below), the seeds are neatly- I might even say photogenically – arranged. I took the time to count the contents of one pod, before it was dis-articulated by the wind, and came up with a count of exactly 162 seeds. Actually, there may have been a few more, but I was momentarily distracted by something moving in the high grass behind me.  According to the literature, the average milkweed pod will have anywhere from 100-200 seeds, so my interrupted count was well within expectations.

In the case of the above pictured pod, I had to pull it open to reveal its internal structure. It didn’t take a Bigfoot-like effort to do this because there is a naturally weak seam on the lower outward facing edge. Normally the casing dries out and splits along this seam of its own accord. Commercial milkweed growers (yes, there were such folks) collected the green pods  in late August and waited until they were down to a 10% moisture content. Their pods were opened with gentle agitation. There is a center “wall”, running the full length of the pod, and the floss end of each seed is loosely anchored to this septum. With the central seed core exposed, passing breezes are allowed to lift up the edges of the flat seeds and each unit, seed and attached floss, launches into the air.  Once one goes, the rest will peel off in rapid succession and leave the central septum bare (see below). These flossy parachutes lift their heavy seed load aloft and carry it as far as the wind will allow.

Scientists talk about the spread of air born seeds in terms of what they call a “seed shadow.” This represents a 4 dimensional area determined by the length, width, height, and even “hang time” of the seeds as they leave the maternal plant. Given that milkweeds have large seeds, this shadow is short but dense. Speaking of scientists, I feel compelled to tell you a few more useless Milkweed facts as determined by researchers. I mentioned commercial growers earlier, because there have been several pushes over the years to make use of milkweed floss. During World War II it was collected as a Kapok substitute and more recently it has been investigated as an insulator & textile material. Apparently this floss is equivalent to the density of goose down and possibly better in terms of insulating qualities. It takes 500 pods to accumulate 1 pound of this magic floss. If I’m figuring right, that means that one would need to harvest 75,000 seeds in order to get one measly pound of floss.  I know it would take far fewer geese in order to get the equivalent amount of down, but I wonder if a pound of goose feathers is heavier than a pound of floss?

Finally, I would be remiss not to mention that milkweed floss is extremely water resistant when endowed with its natural coating of wax. When that wax is removed, however, it can absorb 75% of its weight. This led some researchers to explore it as a potential diaper material. Unfortunately, I think this is certainly an impracticable path to follow. Everyone knows that Bigfoot fur is far more absorbent (consider this a hot tip for you potential entrepreneurs out there).

October 16, 2009

Mother Nature Fooled?

Filed under: Uncategorized — wykes @ 4:46 pm

Humans like to categorize natural events into “earlier than” and “later than” normal time slots. If there is anything we should have learned by now is that there is really is no such thing as “normal.”  There certainly are “average” and “typical”  times for events to happen (such as flowering dates, nesting times, etc.), but even these will change over a long period of time. Nature is always experimenting and pushing environmental limits while asking (more like insisting) that the living world play along. She does these things on  a time schedule far different than our individual life spans so it is difficult to see what’s actually going on. It is safe to say that the only normal thing about nature is that she will never settle for normalcy. We know it’s not nice to fool Mother Nature, but we continue to try it. But, there are circumstances when she appears to fool herself and there is cause to wonder if she will exact self-punishment? I believe the answer is yes.

In the seasonal cycle of things there are two times of year when temperatures are cool and daylight time equals nighttime. The natural events surrounding the Spring and Fall equinoxes couldn’t be more opposite. One signals the awakening time and the other marks the season for closing down shop. Every year, however, plants and animals are tricked by these identical conditions and they start to think spring/summer in the fall. Chorus Frogs and Peepers will chime out a few hesitant croaks as if it were March and Redbuds will re-bloom.  A classic example of this scenario is the scene depicted in the photo above. In this case, a Red-Panicled Dogwood shrub contained flower clusters and berry clusters on the same plant in mid-October. It is “normally” impossible to get such a picture  without Photoshop trickery.

Granted, this type of dogwood is “normally” a late bloomer among the ‘dogs. Unlike their showy early spring cousins, they “usually” show flower in July and by mid-August are  “typically” well into setting up their fruit. The October shrubs “always” exhibit  purple leaves and clusters of white berries. Here  again, however, there is no normal or typical. Mother nature will deal harshly with this apparent error. There are only a few weeks left before the leaves must fall and this plant has wasted some valuable energy. The flowers will shrivel and die and the plant will be left to deal with the coming winter using depleted reserves. Only the Witch Hazels are allowed to do their blooming at this time. It’s in the contract, Doggy – read the fine print.

Another situation, which definitely defies the season, was an active  Monarch Caterpillar (see one of them above). I took this picture last week as morning temperatures were slowly climbing into the upper thirties.  The previous night had dipped into freezing range yet this beast was still crunching away at the remaining milkweed leaves. There were three caterpillars in a stand of about a dozen milkweed plants – probably all laid by the same procrastinating female. Based on the age of the ‘pillers, who looked to be in their 5th instar and around 2 weeks of age, this means their mother would have laid her eggs sometime during the last week of September!

In short, this Monarch mom goofed. “Normally,” all late summer Monarchs turn off  their reproductive desires and begin to head south. The big flight begins in late August and reaches a peak around mid-September.  The last migrant has “usually” gone south by early October. All this haste is necessary because the flight will take the migrants all the way to the mountains of Central Mexico. In other words, our caterpillars were still egglings when the rest of the local monarchs were practicing their Spanish.

It takes a month to complete development from egg to larvae to adult. Even if our caterpillars survive the coming week and make it to chrysalis stage, they would not emerge until Halloween week. Now that’s scary. I can confidently predict that they will not get that far. They will shrivel and die just like those dogwood flowers.

Ahh, but let’s not loose hope. This is a part of Nature’s plan. If, by some chance, this November turns out to be balmy and December follows suite, then these caterpillars and that dogwood would be the first in line to reap the benefits!  In the end, these aberrations are simply natural experiments – shock absorbers to deal with the constant changes that occur over time. No fooling.

October 13, 2009

A Living Breeze

Filed under: Uncategorized — wykes @ 10:09 pm

Sunday dawned cooler than the previous few autumn mornings at the Detroit River mouth. It promised an especially cool autumn day. The sky quickly phased into a bright blue canvas as soon as the sun crept over the Canadian skyline, rolled over the islands, and struck the American shore.  A crisp Northwestern breeze pushed against the dawn but had no effect upon it – it rose at normal speed. The Fall season here at the river mouth can be exciting when these morning winds come from the east on the heels of a clear sky. They bring with them huge migrating flocks of raptors. The hawks begin coming around 9 am and continue, on some days, until the sun retreats at 7 pm or so. Early in the fall, thousands of Broad-winged and Sharp-shinned Hawks will ride them south from the northern forests. This fall some 20,000 Broad-wings were recorded by human observers as they made the passage over the river in September. October usually brings thousands of Turkey Vultures along the same route – following the same breeze.  Westerly or southern breeze usually hold back any given flight.

This October had yet to host the “big flight” of Turkey vultures as of the 11th of the month. The winds had not been favorable. Some groups had crossed, but only in scattered patches and these buzzards were forced to tack into the breeze. Saturday the 10th was a good day, with 8,000 migrants, but not a break-out day by any means. The big black birds had to bend their wings into a “W” formation and angle across the sky in order to make southwestern headway. This day looked to be yet another one of those off days – if you can call a flight of 8,000 birds “off.”  In spite of wind direction, however, it turned out to be a break-out day. I was fortunate to witness at least a portion of it.

I saw my first vulture about 9:45 or so. This bird slid by going in exactly the wrong direction! It was a lone bird heading north- probably looking for a thermal to ride or adjusting his GPS unit. My concentration re-focused on earthly matters for the next quarter hour as I scanned the river for waterfowl and watched a few late season swallows swirl about for midges. The next time I looked up the blue sky was full of vultures. I mean full. One gang of black forms turned lazy circles over the field to my north while another rode high up on a mass of warm air directly over my head (see here). A third group formed a continuous horizontal column stretching off beyond sight from the eastern horizon and feeding into the circular masses.

The circling groups, known as kettles, were impressive enough (see here). These consisted of hundreds of individuals riding a thermal heavenward like a reverse tornado. At a certain point, the top birds would begin to peel off one by one and glide off like a sinuous ribbon. Never was a wing beat executed during this whole set of maneuvers – it was all performed with outstretched and motionless wings held up at a slight angle. But it was the sight of the incoming birds, those streaming in from the horizon, that impressed me the most. It isn’t often that we get a chance to stretch our eyeballs at such a continuous stream of life (see here).

The incoming steam was organized into a band about 10 birds wide and thousands long. Like a meandering river, the column vacillated and danced according to the whims of the breeze. At one point the band angled and veered north for a short spell then fluidly shifted back to a straight western course. As it passed directly overhead, I could clearly make out the details of the individual fliers themselves. Upon reaching the shoreline sky, they broke up into kettles and augured upward.

The aerial show continued unabated for the next half hour until I had to cut my observation time short (neck spasms, you know). The migration continued throughout the day as if some great hand had opened up a floodgate. The sum total of day’s migration turned out to be in excess of 16,000 (officially 16,292). I was privileged to see at least a few thousand of those birds.

It might seem odd that I would get excited at a flock of buzzards, but I hope you see that they represent something much more than that. It allowed me time to imagine what it must have been like to see those so-called endless flights of Passenger Pigeons or Buffalo herds back in the old days. It also allowed me the opportunity to appreciate a tide of modern life that still exists in spite of our hectic modern day world. As you can see, it also turned me into a  writer of rambling nature prose sounding very John Muir-like. I’ll apologize later, but being witness to a living breeze tends to do that to a fellow.

October 10, 2009

Les Ile aux Serpentes

Filed under: Uncategorized — wykes @ 8:14 pm

Long ago the Lake Erie Islands were known as “Les Ile aux Serpentes” -a French name meaning “the Snake Islands.” Stories, nurtured since prehistoric times, centered on the abundant snake population of these remote islands. It was reported  by former Indian captive James Smith that the natives held a belief that the island snakes actually turned into raccoons every fall and that they returned into snake form in the spring. This belief was based on the abundance of both species at certain times of year. Another tale told of a lethal “Blow Snake” that haunted these isles. Over time, raccoons were recognized as untransmutable beasts and the islands slowly shed their ominous snaky nature. Although the rest of the 18 “Ile aux Serpentes” have been given non-serpentine names likes Gibraltar, Bass & Kelleys, one of them, a small piece of rock just north of Put-in-Bay, is still called Rattlesnake Island.

The islands are still heavily populated by snakes today. Perhaps the most celebrated residents are the Lake Erie Water Snakes.  This species is a subspecies of the mainland form of Northern Water Snake but they have been isolated from them since glacial times and are starting to take on a different appearance. Typical Lake Erie individuals have a washed out look which de-emphasizes their dark banding pattern. Because their entire population is restricted to the 25 sq. mile area of the islands they are considered a protected species.  “Water Snakes Welcome Here” signs (see here) are posted along the beaches to advise and inform island visitors and residents of this treasured resource. During my autumn vacation to South Bass & Kellys Island I didn’t really expect to encounter any of these unique creatures due to the late season. Fortunately, I was wrong.

Nearly every beach either had evidence of their presence in the form of shed skins (see above & here) or the creatures themselves. On the north shore of South Bass I nearly stepped on a very large individual basking on the sunny rocks. Neither of us were aware of each other until the last moment and each showed mutual surprise.  I shouted out a hearty verse of heavenly praise and he virtually lept into the air, beat a hasty retreat across the pebbles, and dove into the water – swimming a short distance then diving under the waves. At the time, I swore that he was a fully 5 feet long, but later re-considered this upon finding out they don’t get much over 3 1/2 feet long.   Later, I came upon a smaller one sunning on the concrete slabs along Put-in-Bay (see below and here). He quietly slipped back into his retreat before I could approach any closer.

I did find a dead individual washed up on the beach, but it was in near skeletal condition. This one did provide an opportunity to get a closer look, however. The mouth was a treat to behold. It contained no fewer than 80 needle sharp teeth – all of which pointed inward. Augmenting the outer rows of 10 teeth on each side of the mouth, a dual row of  40 teeth ran down the center of the upper palette. In other words, the roof of the mouth contained four rows of teeth amounting to 60 teeth! Water snakes use this armament to procure fish, but will use it upon human intruders if captured. A coat of anti-coagulating saliva on the teeth makes for a bite that will bleed like a puppy when inflicted.

The Ohio State University has been studying these snakes for decades. On one point of the island I came upon one of their “Snake Mats” at the foot of a cliff next to Bass Island State Park (see below). These prominently marked structures – really nothing more than flexible black floor mats -were laid out at regular intervals to serve as gathering places for Lake Erie Water Snakes. The spots are visited on a regular basis to capture and mark snakes for study. I will admit to looking under this particular mat, in spite of the clear directions to the contrary (although you will note that the partially obscured letters say “touch” ). I only looked a little bit, by the way. Since my daughter is currently attending Ohio State, I felt slightly entitled.

University research has revealed that the snakes are currently enjoying a population surge due to a surprising reason. Apparently, the introduction of the infamous Round Goby has served as a heavenly gift to this species. They eat them like candy and these alien fish make up nearly 90% of their diet in some locations.  Population estimates of 141 adult Lake Erie Water snakes per km. of shoreline have been proposed along with a total population of 10,000 individuals.

For now, the Erie islands will retain their position as the Serpent Islands.

October 6, 2009

Buzzards on the Beach

Filed under: Uncategorized — wykes @ 9:11 pm

October out on Middle Bass Island is about what you’d think. On a clear day there is no prettier place, but on a gusty cold day the place takes on a harsh edge. The island is well out into the gray choppy waters of Lake Erie. Here the prevailing winds are incessantly beating up on the west facing shore of the island even on nice days. With morning temps hovering just above 45 degrees, the setting certainly made for some brisk beachcombing.

Naturally I expected a solitary walk when I hit the beach at sunrise the other day. Certainly no-one else would be foolish enough to be out on a day like that. There should be plenty of uncontested fresh offerings in place. The wind had been blowing hard all night- sending waves rolling in at a steady pace. No sooner would one break and crawl noisily over the pebbled beach than another would break on the heels of the first. Each watery hit shuffled the loose limestone rocks as if they were marbles. The sound of a million mumbling stones clunking about for the millionth time was mesmerizing. A long rolled mat of water celery marked the high water line like a lazy emerald serpent. Perched upon that vegetative snake were bits of flotsam and jetsam cast up from Erie’s belly. There were scattered pieces of driftwood, a sizable walleye carcass, and a battered bill cap with an Interlake Steamship Co. logo on it.

I reached down to pick up the cap and noticed out of the corner of my eye that I was not alone there on the shore. Far up the beach, a pair of juvenile Turkey Vultures were also working this wind blown stretch. They were alternately picking away at a large eyeless Sheepshead and keeping their own eyes on me. Vultures are cautious creatures and don’t normally hang around when caught out in the open. I stopped to watch them while I still could. In the low light of morning, blurred by drifting clouds of wave mist,  they appeared downright prehistoric. Their wrinkled naked heads and jerky mannerisms gave them the look of  creatures that were out of the dawn of time rather than just the dawn of  day.

I couldn’t be sure if these were resident island birds or migrants from the far Ontario shore. Turkey Vultures migrate south during the month of October and the big flight was underway. Wherever they were from, these were probably nest-mates from earlier in the season. By next spring they would sport red heads and white beaks, but they both still had the pinkish gray skin head and dark-tipped beaks of youth (see here and here). The pair nervously shifted position to walk down the shore toward the carcass of another fish. After every step they looked back and occasionally ruffled their peculiar bottle brush necks. At one point the sun gleamed straight through their large nostril openings as if to highlight their extraordinary ugliness.

For just a moment, we three were the only creatures on earth in this wild place. I’ve seen thousands of vultures before and will see as many in the coming years, but my Bass Island buzzards seemed temporarily special. I tried to raise my camera one more time but the scene through my viewfinder emptied as the pair launched into the air and rose up on the high breeze. They turned eastward and glided out of sight over the treeline behind me.

October 3, 2009

A Clam in Time Saves Nine

Filed under: Uncategorized — wykes @ 3:49 pm

I was walking the shoreline east of Port Clinton, Ohio last week and saw that the wind had created an extensive wind tide. This  effect, called a seiche (a Norwegian word I believe), involves a bit of bathtub science in which the lake basin acts like a tub of water being tipped by a prolonged western wind. A wall of water is pushed toward Buffalo and the western shore is left waterless. Winds up to 50 mph had exposed at least an 1/8 mile of open sand flats extending from the rock-covered shore to the harbor break walls (see here). The water level dropped by 8 feet in some places along the shallow basin of western Lake Erie. For some the phenomenon posed a temporary irritation but for others it posed a deadly trial. Totally aquatic beasts, such as fish, clams, and water plants are put to the hardest test. Open wind-exposed sand is hardly conducive to maintaining a wet life.

The sand substrate in the near-shore environment offers little even on the best of days. This habitat consists of a continually shifting bottom habitat. Only a few patches of water celery and a few scattered boulders provided any stationary cover. Nutrient rich waters make this place worth whatever effort is expended here. One of the tougher inhabitants of this zone – at least in this particular place – were large native calms (aka mussels) known as Floaters. Contrary to their name, however, they don’t float or even tread water. They pretty much remain in place on the bottom until prompted to move by hunger or boredom.  I came upon quite a few of these creatures out on the flats. All were attempting to dig down into the substrate to avoid the dangerous bout of dryness thrust upon them. Their efforts created winding trails carved into the hardening sand. Each trail ended in a partially entrenched clam (see here & below).

The problem is that mussels don’t move very fast. “Glacial” would be a good way to describe their pacing. When they do move they do so using a large white muscular foot that extends out and swells much like an anchor. The heavy mollusk pulls itself forward to the anchor point and repeats the process. A clam journey is measured in inches rather than feet. (You can see this foot sticking out along the lower right edge of the shell in the view below). Since they have the reaction time of a refrigerated snail, they can’t respond quickly to the lowering water brought about by a seiche. By the time they are thinking “hey, the water is going away- I’d better dig in…,” the water is already gone and they are forced to deal with hard-packed sand.

If they can bury themselves properly, they can survive for quite a while on the water entrapped within the tight lips of their mantle folds. Most of the clams I found were well on their way to security.

Unfortunately, one of the nasty realities in these parts are the colonies of Zebra Mussels that infest nearly every clam (see here and below). Zebras need a hard surface in order to carry out their devious plans to take over the earth. Out in the sand shallows, the protruding portion of the native Floaters provides a dandy place to set up shop. These colonies can get so large that they will literally rob their host of food and eventually kill them. One of the most disastrous long term effects brought about by Zebra Mussels is that they are reducing our native Clam population.

Every Floater I encountered was encrusted with Zebra Mussels. One very large individual (see above) was not yet totally buried so I decided to  scrape away every zebra I could as a small act of kindness. Life is tough enough without this extra added burden. This job was not an easy task given that the mussels were individually attached to the shell and each other via strong byssal anchor threads. Once the job was completed I ended up with a pile of over 100 zebra shells laying on the sand next to their former host (see here).

The zebra-less Floater probably didn’t even realize that she was lighter until long after her life-giving water had returned. This clam did not look at me with soft eyes and say “thanks” as I repositioned it deep in the sand. Since she has no eyes and only a quarter of a brain to render such an emotion, this is no surprise. But maybe, just maybe, this one will survive long enough to produce at least nine more clammlets in the future. This provided me a small measure of comfort out there on that cold Lake Erie sand flat.

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