Naturespeak A naturalist's view of the world

June 7, 2008

A Squirrel’s Nut Forgotten

Filed under: Uncategorized — wykes @ 7:12 pm

  Because squirrels are endowed with peanut sized brains, walnuts are given a crack at life. Squirrels, you see, have limited memories. They don’t remember where they put all their autumn buried nuts and therefore don’t eat them all during the winter. These forgotten nuts are enabled to sprout and make their bid for treedom when spring rolls around. It is believed that most walnut trees get their start this way.

  Sometime last autumn my local A.D. D. Fox Squirrel decided to bury one of his precious walnuts right next to my house foundation and then promptly wiped its location from his memory banks. I discovered the resulting tree sprout a few days ago when trimming around the yard. Unfortunately I had to pull up the ill-placed plant, but saw in its demise an opportunity to talk a bit about tree nuts and germination. Your parents probably never got around to giving you the germination talk did they? Well, it’s high time we got to it.

  Take a look at the graphic photo above, and you’ll see the young walnut sprout with its dirty nut still attached. Unlike many plants that actually lift their seeds up into the air when they sprout (like bean sprouts), walnuts leave their nuts in the ground.  They are hypogeal germinators. This means that they leave their nuts in the ground -which is what I just told you. What I didn’t tell you is that the inside of the nut – the nut meats – are actually called cotyledons (see here this pinkish heart-shaped structure). The cotyledons provide support for the formation of the main root and the sprout.  In this type of germinator the cotyledons are power supply to get things going.

  The root, or radicle, busts out of the shell and immediately seeks a downward direction. These cells are wired with a gravity-oriented component that guarantees their mission success. The tap root (see here in broken form) grows deep into the soil and acts as an anchor and feed line for the new tree. Walnuts are able to establish an extremely long tap root in a short order of time. 

  The other growth coming out of the split nutshell, next to the radicle, is called the epicotyl. This is the part that seeks to fight the forces of gravity as a heaven bound leafy sprout. The sprout generates leaves and the leaves start the photosynthetic process. Walnut seedlings are often able to achieve over 36 inches of new growth within a few months and even more during their second year.

  Now, I understand that knowing all of this may not change your life in any significant manner, but it might be a cause for poetic pause next time you see a seedling walnut. Repeat after me: “A squirrel’s nut forgotten is a Walnut tree begotten”.  Aren’t you glad we had this little talk?

June 4, 2008

The Emerald Master of June

Filed under: Uncategorized — wykes @ 7:42 pm

  The Green Darner is a creature that defines the color green. Not that their maroon is anything to sneeze at, but one look at the deep emerald shade of the thorax is enough to confirm just how appropriate the species name really is. The marbled translucence is gem-like in quality. It is fitting that these three inch long dragonflies, the largest in Michigan, happen to be a prominent part of this very green month of June.

  Scientifically they are known as Anax junius. This name is a combination of the Greek word for “Master” or “Lord” and the Latin for the month of June (I think you can figure out which is which).  Historically, and hysterically, they have long been known as Devil’s Darning Needles and Snake Doctors. As darning needles in the service of Satan, they were supposed to have the ability to sew your lips shut. I admit, the devil association aside, I have encountered more than a few people over the years who might have been good candidates for such a treatment (but my lips are sealed on this matter). Fortunately only the darning needle part has stuck. Their long slender bodies do have the appearance of a sock-darning needle, kinda – if you get rid of the wings, the eyes and the legs and… , well, never mind.

  This precious stone of an insect only lives for a month or so as an adult.  The individual pictured above is a female freshly emerged as an adult only 24 hours before this shot was taken. Equipped with strong transparent wings, up to 4.5 inches in span (see here), huge compound eyes, and a set of six hairy legs this creature earns the title of Mosquito Hawk. They are very adept at capturing these pesky creatures- which have been proven to work for Lucifer, by the way.

  Darners have the ability to fly vertically, horizontally, and backwards as well as the strength to propel forward at speeds in excess of 18 mph. One website quotes a figure of 53 mph as the top speed, but something about that doesn’t sound right (at that speed I believe they would be turned into darning needles as all their appendages would rip off from wind shear!). If I am wrong on this point, please let me know so that I can sew my lips shut for a few days.

  The large eyes which envelope the head are aggregations of thousands of simple eyes.  The point of view of a dragonfly is nearly 360 degrees and they can pick up the motion of flying prey coming from any direction. I remember reading somewhere that the downward facing eye columns are employed as air speed indicators (judging relative position of ground items as they pass by). I think it was in a comic book, but I’m not sure. I do know that there are backward facing eye columns that detect movement from behind when the animal’s face is pointed foreword. The only other place where this latter trait is found in nature is on those of us who are teachers and/or parents.

  Mosquitoes and other prey are scooped up in a hairy basket created by the legs (see here) and often eaten on the wing. Another website, this one more believable than the first, contains a brief account of a Darner actually nabbing a hummingbird. A bunch of birders who witnessed the incident shooed the dragonfly off as the pair tumbled to earth. Who knows what would have transpired had not those pesky birders interfered?

  Green Darners do not come from humble roots. The Juno of the summer sky comes from the Kracken of the spring waters. As children they are pale dun colored killers. The aquatic nymphs are large creatures (see here and here) that need to spend several years lurking in quiet ponds until they attain their final size. These mini-predators have two mouths. One mouth is located where it should be – under the face.  The other one is located at the end of an extendable arm, called a labium, that is tucked away under the head. By extending the “arm mouth”- in alien fashion -the nymph can latch onto tadpoles, larval fish, and other insects (see here). 

  Aside from eating the occasional hummingbird (maybe!) the adults seem to have a taste for honeybees and can be a pest around commercial hives. This is a small price to pay, however, for having such a beautiful and beneficial insect around.

June 2, 2008

In Lupine Fields of Blue

Filed under: Uncategorized — wykes @ 8:14 pm

“In Lupine fields of blue I tread

Where sun and Viceroy rule,

And Meadowhawks with Robber flies

Engage in ancient duel.

 

  There’s something about a walk through a sunny meadow that inspires bad verse. When that meadow is flush with blooming wild lupines, as was an open glade at the Petersburg Game Area, the inspired verse is bound to be Nitrogen enriched. Petersburg is located in the sandy region of western Monroe County and is one of the few regions in the state where the Lupine thrives.

  Lupines are members of the legume family – a group known as the Fabaceae or bean family. (Supermodel Fabio is a human bean, so one could conclude that he too must be in this family- yes? No.)  Legumes are known for their ability to fix Nitrogen from the atmosphere and enrich the soil and thus my verse-enrichment comment.

  I have no excuse for the Fabio comment except that lupines are supermodels of the flower world.  These fantastic plants bloom in upright spikes with dozens of flowers each. Individually (see here), the flowers look like tiny bonnets and are very much like garden pea flowers. The lower two petals envelop the delicate floral structures (the reproductive parts) like a pair of cupped hands. A light downward pressure, such as applied by a landing bee, exposes the pistil and stamens for pollination (see here).

  These lupines sprang forth due to the encouragement rendered by an earlier controlled burn at the site. Periodic fires are employed by the MDNR to control the woody vegetation and return the place to something closer to its native Oak opening condition. The mid-spring meadow that flourishes in these ashes is also host to Wild Strawberries, Pearly Everlasting, Salsify, and native grasses.  Mid-day in that mid-spring meadow is a butterfly, dragonfly and robber fly paradise.    

  Meadowhawks were the predominate dragonflies but several butterfly species were active in the sunny glade. A newly minted Viceroy allowed herself to be photographed and then carefully plucked from her perch for an underwing portrait.  Nearby, an American Copper flashed some colors and along the shady edge a Little Wood Satyr danced in the dappled sunlight.

  Painted Ladies were present on this day also, but only in larval form on Pussytoes.  To find them, I had to bend down low to investigate one of the Pearly Everlasting (a.k.a. Pussytoe) patches. The growing caterpillars weave several leaves together to form a protective chamber (like this) where they can eat away at the “Toes” in relative safety. Most of the chambers were empty but one did contain a spiny Painted Lady larva that squinted as it was exposed to the bright sunlight.

  One butterfly not in evidence in the Lupine patch was a tiny butterfly called the Karner Blue. It used to be found there but disappeared sometime in the 1980’s. This tiny species is a federally endangered insect that depends upon the wild Lupine for its existence. The larvae feed solely on this plant.

  Researchers are looking to re-introduce the Karner Blue to its old haunts once the food plants are dense enough to support a new colony. Until that time, we’ll have to be satisfied with this incredible piece of meadow without its extra shade of blue.

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