Naturespeak A naturalist's view of the world

February 5, 2008

Stone Cold Chuck

Filed under: Uncategorized — wykes @ 8:53 pm

    A mid-winter woodchuck is basically dead to the world. When I say this, I don’t mean “dead” as in the midst of a deep sleep, I mean it as being as close to death as you can get without actually being actually so.  Despite the apparent ease with which Malverne Mel, Stanton Island Chuck, Pardon Me Pete, and Punxsutawney Phil rise out of their stupor to make their Ground Hog Day predictions they can do so only with the heavy assistance of their handlers. I believe that Phil has a heated burrow with a hot tub and tiki bar at his pad.  He is not one of the common ‘chucks, but instead one that is forced to deny his very woodchuckiness.  It is rumored that he even chucks wood – an activity totally against the species grain.

 Most wild woodchucks, this time of year, are curled up into a tight ball and engrossed in a self induced state of denial. Deep within their burrows they are hibernating and completely removed from the realities of the harsh world above (see here a picture of a hibernating woodchuck- click on the 6th picture down).  You could dig ‘em up and put them in front of the television cameras and they would say exactly nothing.  It’s not an antisocial thing, rather a physiological thing.

  There is a very select group of mammals that have the ability to hibernate.  Animals such as the Woodchuck, Thirteen-lined Ground Squirrel, Jumping Mice and all of our regional bat species choose this strategy.  Others such as Opossums, Raccoons, and Skunks retreat to their dens to sleep off bouts of severe weather, but they need to come back out to re-fuel throughout the winter. They sleep but don’t hibernate. Even Black Bears don’t truly hibernate – they go into a deep sleep. Winter bears can be roused relatively easily, so it’s a wonder why folks don’t go about waking them up on Groundhog Day to ask them for predictions. The answer to that question should be fairly obvious (an angry bear will not tolerate men in top hats and crowds of reporters with flashing cameras).

  The answer to the question asking why true hibernators do what they do is not so obvious. The impending seasonal lack of available greens certainly forces the decision out of the woodchuck, but this is not the entire answer. The cottontail rabbit, a mammal of similar size and food needs, chooses to scrape through the winter as an active creature.  For now let’s just gloss over the thing and simply say that the ‘chuck and his fellow members of the “Hiber Nation” do what they do because they can.

  Hibernation is controlled by body chemicals.  A substance, unimaginatively called H.I.T., or Hibernation Inducement Trigger, is produced at the request of a structure in the brain called the hypothalamus. This control center, located mid brain under the thalamus, east of Eden, and just ahead of the hippocampus, is prompted into action by the shortening days of autumn. Once this chemical is circulating in the bloodstream, all kinds of things begin to happen. Woodchucks become Ground Hogs, for instance. They begin to eat like, well, hogs and put on a rich layer of fat – including a special patch of fat called brown fat between the shoulder blades.

  Next, the corpulent creature vows abstention from further eating, makes one last visit to the bathroom, crawls down in his den and curls up.  The transformation into hibernation mode is gradual but dramatic. Blood composition changes, hormonal balances are re-figured, insulin levels are increased, and vessels dialate (constrict) in order to maintain blood pressure. Breath rate, heartbeat, and body temperature all take a plunge.  This isn’t napping!

  A woodchuck in full hibernation is cold to the touch and appears to be stone dead. From an active body temperature around 95 degrees F the critter has descended to around 46 degrees F. The heart only beats about 5 times a minute (as opposed to an average of 100 beats per minute) and the breath rate is reduced from 30-100 per minute to once every 5 minutes. Only the heart and brain are kept relatively warm and they are fed by the reserves of body fat.

  Researchers have conducted all kinds of experiments, some down right evil, in their attempts to understand the mysteries of hibernation, but two stick out in my mind. In one, a hibernating chuck was sealed up in an airtight jar filled only with Carbon Dioxide gas for one hour.  This treatment would have killed a summer chuck within minutes, but had no ill effect on the slow respiring winter chuck.  In another experiment, blue dye was injected into the leg vein of a hibernating ground hog. The dye didn’t circulate to the rest of the body until springtime when the critter woke up. That same experiment on an active animal resulted in the dye reaching all parts of the body within a few minutes -even tinting the eyeballs blue.

  Only warming ground/ air conditions or the internal ringing of a pre-set biological clock will awaken our sleeping beauty (while not exactly beautiful, chucks are kinda cute).  Quick metabolism of the brown fat is involved in this, but we’ll talk about the awakening procedure some other time. For now I’d like to let sleeping chucks lie about the weather.

February 3, 2008

So, What Did the Groundhog Say?

Filed under: Uncategorized — wykes @ 9:03 pm

Yesterday was February 2. What significance that day had for you depended primarily upon your culture or lack of it. Be you a witch, pagan, wood sprite, hill folk, city folk, catholic folk, fossorial mammal or a combination of the above (although you can’t be a pagan catholic you could be a hill witch), your explanations will vary.  Billy, Phil, Wiarton, Shubenacadie, and Dave disagree even though they are closely related. One thing that is fairly certain is that Groundhogs had very little to do with it.

  For many of us yesterday was Groundhog Day. This meant that the name of Punxsutawney Phil was invoked and images of the sleepy forecaster were plastered across the news media. Phil saw his shadow, they say, and his top hat wearing translators have forwarded his declaration that six more weeks of winter lay ahead. 

  There are dissenters in the species rank, however. No fewer than 17 “official” ground hog forecasters have cropped up over the years and their predictions are rocking the very foundation of Ground Hog Day. Dunkirk Dave, of New York saw no shadow and boldly proclaimed the early onset of spring and Shubenacadie Sam (Nova Scotia), Buckeye Chuck (Ohio), and Jimmy the Groundhog (Wisconsin) agree with him.  Only Sir Walter Wally (North Carolina) and West Indies Wilbur (do they even have ground hogs in the islands?) side with Phil for this year’s prediction.

  It’s no wonder that the others are gnashing their rodentine incisors.  Phil – actually a series of creatures since 1887, better called “the Phils” – has (have) been wrong over 60% of the time.  That is worse than guessing, in case you are doing the math.  Phil has been giving the brotherhood a bad name, so the others are trying their paw at this game but are proving to be just as unreliable.  While Gus Wickstrom’s Pig Spleen forecast method has proven only slightly more accurate, the truth is that Ground Hogs shouldn’t be expected to possess any prognostication abilities.

  I suppose we could blame the Germans.  German immigrants settling in western Pennsylvania brought an ancient old world tradition with them and planted it firmly on American soil. Although the original tale centered on a bear, the idea of a creature rising up out of the ground to see – or not see (that is the question) its shadow was central to the story.  “Seinen Schatten Sieht, so kriiecht er wieder auf sechs wochen ins Loch”, so goes the rhyme – if the bear sees his shadow on Feb. 2 he will crawl back into his hole for another six weeks. Over time, hedgehogs and European badgers have been interchanged with the bear.

  We can’t place blame on the early Catholic Church for trying to clean things up, but their efforts have confused the situation a bit.  In the ancient days, the period around Feb. 2 fell exactly half way between the winter solstice and the spring equinox.  This was the time to celebrate the renewal of spring with pagan sacrifices, the invocation of wood spirits, the heavy intake of spirits, and the induction of new witches into the Land of Oz.  The church astutely chose to place a solemn ceremony on that very day and call it Candlemas.  That way everyone could still get together for a big party but put their celebratory efforts toward the forces of good.

  During Candlemas, all the church candles to be used for the year were blessed.  The candles represented Christ and his role as the Light of the World – this melded well with the concept of increasing daylight which brought healing to the land and the soul.  The candle/Christ tradition still holds today but the pagan underbelly is still there. Magical earth powers are sometimes credited to the candles. Blessed candles had the potential to ward away “tempest, thunder, devils, fearful sprites, damaging hail, and frost” according to one old English rhyme.

  It had long been tradition (possibly as early as the 4th century) to use a little phrase during Candlemas which went something like this: “If Candlemas is mild and pure, winter will be long for sure.”  Another rhyme went “If Candlemas day be bright and clear, there’ll be two winters in a year.”  Does this sound familiar?  Does it? Huh” Huh?

  It is likely that this Candlemas phrase was an attempt to replace the earlier pagan ditty which used the image of a sleeping animal rising from the earth and casting a shadow.  Basically it didn’t work. Instead a brown bear became a hedgehog then a badger and finally, in the absence of any of them, an American ground hog. Somehow the deep meaning of the renewal story got trivialized into a movie starring Bill Murray.

  So you see, ground hogs got sucked into this thing and have unjustly suffered in the limelight. They now have to endure the label of groundhog when their proper name is Woodchuck.  Because they spend their winter in a state of suspended animation, they don’t know diddly about winter and are forced to endure handling by strange men.

  Just how “out of it” winter woodchucks really are will be the subject of my next entry. Prepare ye the way for the hibernating ‘chuck, but he ain’t coming out on groundhog day.

February 1, 2008

Mayflies in February

Filed under: Uncategorized — wykes @ 9:02 am

  Out on the big waters of the Detroit River and Lake Erie life goes on beneath the cover of winter ice. Ice fishermen are well aware of this fact, although their version of the story is very icthyocentric (fish oriented).  To them the meaning of life comes in the form of a 14 inch Perch or a slab-sided Bluegill. Heaven’s gate is a round hole through the ice providing access to an endless procession of filets.  But when the point is forced, experienced fishers will grudgingly admit that there is more than just finned life beneath their feet.

  Truth is, just about every aquatic life form from mudpuppies to crayfish are active during the winter.  I saw a very large bullfrog tadpole cavorting around an open water patch two weeks ago and have heard reliable stories of painted turtles swimming under the ice. Yesterday a friend relayed a story to me that a fellow ice fisherman detected something “that looked just like a stick bug” crawling up out of his hole and out onto the ice. The unexpected guest turned out to be a Water Scorpion – not a scorpion at all but merely a spindly relative of the giant water bug. 

  One winter water critter that all fishermen are familiar with is the ever popular “wiggler.” These creatures are sold as bait, along with leaf worms, wax worms, mousies and the like. Unlike their shelf mates, wigglers are a natural part of the local offshore waters. Wigglers are actually insect nymphs officially known to the non-bait world as Hexagenia or Burrowing Mayflies (see here).

  It’s nice having such easy access to these entomological specimens because it saves you from taking a very cold dive to the lake bottom.  For a buck seventy-five, you can walk into a local bait shop and come out totally dry and in possession of a plastic bait container crammed with 24 mayflies. I discovered that I had 25 in my recently purchased container, but decided not to return the extra one (although I felt guilty for several prolonged minutes).  I released my charges into a larger pan of water for closer examination and would like to share a few observations with you.

  Swimming Mayfly nymphs manage to propel themselves in a manner similar to miniature whales – very clumsy tiny whales.  They rhythmically wave their abdomen up and down in order to move in a haphazardly forward direction. In other words, they wiggle (which is why fishermen call them wigglers rather than tiny clumsy whales). Burrowing mayflies are not built for sustained swimming, but they can be forgiven this aquatic inadequacy because they are built for, you guessed it, burrowing in the bottom muck. This is why they call them…never mind, you already know what I am going to say.

  Take a look at this shot and you can see that an individual nymph is about 2 inches long. I’ve provided a dime for size comparison (Mr. Roosevelt is just under ¾ inches in diameter here).  Those feathery things lining the side of the abdomen are gills.  Three tail filaments trail off the back end and six robust legs can be seen at the front end. A pair of beady black eyes, a like number of antennae, and a set of substantial tusks are evident on the head. All the parts are tinged with a pleasant golden hue that almost makes them look appetizing – at least to a hungry fish.

  It is the full intention of every young burrowing mayfly to become a big mayfly so they need to deliberately avoid predators while fulfilling their personal destiny to get fat. They start off as eggs laid the previous summer by the flying adults. Over the course of the next year, the nymphs (a.k.a. naiads) eat algae and detritus, and shed their skins many times to accommodate their growing size.

  Nymphs operate out of a small semi-circular tunnel in the bottom muck which they excavate with a powerful set of shovel-shaped front legs and stout tusks (features best appreciated from this angle). The passage has two open ends and the animal positions itself midway along its length. Constant gill motion keeps a steady flow of water going through the corridor and tiny particles of food are snagged in the hairy fringe bordering the head and legs. Every now and then, the nymph brings the fringe up to its mouth to take in the particulate goodness.

  It is mesmerizing to watch the waving motion of the gills as they pulse in sequential waves from front to back. The gills are operated in pairs. Their tips are brought together over the abdomen and smoothly returned to their side position.  A glance at these two images – first this one then this one – will give you an idea of what I’m talking about.

  My 25th mayfly didn’t last very long.  It died soon after I poured it and its container mates out into the water tray. My consumer guilt now completely gone, I thought about returning it to the bait store for a refund, but opted not to. Instead, I quickly returned the others to their container and placed them back in the fridge. It is crucial to maintain the chilled conditions of winter water because cold water retains more oxygen which is easier to retrieve by gilled critters.

  There are many features of Burrowing mayfly life that are noteworthy but only so much patience on your part to hear them. So, let’s boil this down to a few summary remarks. Ecologically, it’s important to note that Hexagenia are one of the most important sources of fish food in the entire lake system. They are eaten as nymphs and adults. When they emerge as winged flyers in June or July (not May) they will temporarily take over the near shore world and everyone will know them as those “blanky blank fish flies.”  Mayflies live for that brief 48 hour period when they can break the bonds of the water world.  Until that time they bide their time in relative obscurity beneath the winter ice – known only to fishermen and the fish they seek.

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