NATCHEZ NATURALIST NEWSLETTER:
December 16, 2001
Though I knew that our planarian would never affect us like its tapeworm relatives, its discovery caused me a bit of concern. This introduced species, BIPALIUM KEWENSE, is a native of Southeast Asia, from Vietnam to Kampuchea. It has invaded America by way of the soil of imported potted plants. In several US states the species has been reported in greenhouses, plus it's been found in the wild in Florida and Louisiana. As far as I can determine this could be its first discovery in the wild in Mississippi. Here they were surely introduced many years ago when the plantation owner was importing fancy plants from the Orient, something plantation owners in the old days did a great deal of.
One reason we studied planarians back in Zoology 100 was that they are such simple organisms. They lack any kind of lung, circulatory system (no heart, veins, arteries), they have no bones, and their digestive system is so basic that its mouth also serves as its anus. When it eats, using a strategy worthy of any science-fiction monster, it disgorges its muscular pharynx through is mouth, clamps down with it on a victim (earthworms, slugs and snails) and pulverizes its meal bit by bit. Food particles are brought into the planarian body and nutrients are dispersed through a simple three-branched intestine. Planarians possess ladder-shaped systems of nerves enabling incredible powers of regeneration. When zoology students slice them through the head to the middle of the body, in a few days each split develops its own head -- resulting in a two-headed planarian. This may not be as distressing to the animal as you would think. When a mature planarian gets long enough its rear end sticks to the ground, a narrowing develops somewhere on the worm's rear half, and the front end simply pulls away from the rear. The rear then sprouts a head and you have a new planarian.
The troubling part about our planarian is that often plants and animals introduced from elsewhere no longer are controlled by the natural enemies present in their own lands, and they overrun their new environment exactly as kudzu and fire ants have already done here. I would not like to see these planarians eating all our native earthworms, snails and slugs. I just am not sure how serious this discovery is.
Despite moles being such enemies to our cherished earthworms I admire moles. They till and aerate the soil very effectively plus it's a pleasure to see how beautifully adapted they are to their subterranean tunneling lives. A while back I found a freshly killed one on my forest trail, apparently left there as some kind of offering or territorial claim by a fox or other predator, and I placed a picture of it, including a close-up of a digging-adapted front foot, at my nature- study site at http://www.backyardnature.net/moles.htm
My mother did not share my affection for moles. She liked her garden flowers and she was so certain that moles ate her expensive tulip bulbs that she purchased "mole repellers" which theoretically drove moles away with obnoxious buzzes. Well, I saw myself that wherever mole tunnels appeared in her tulip beds, next spring the tulips would be gone.
Zoologists generally agree that moles do not eat tulip bulbs. Moles are almost entirely carnivorous, feeding mostly on worms, insects and their larvae, and they ingest only a little plant matter. If tulip bulbs disappear when mole tunnels appear, it's because other animals, which do indeed eat tulip bulbs, use mole tunnels. In our area the main root-and-tuber eater is certainly the Pine Vole, PITYMYS PINETORUM, which I expect would use any mole tunnel it found. I'll be complaining about Pine Voles in later Newsletters.
CROWS EATING PECANS
The manner in which the crow positions its pecan between its feet as it chisels is interesting. This is exactly as a Blue Jay might grasp an acorn, or a Carolina Chickadee or a Tufted Titmouse might restrain a sunflower seed from a feeder. I don't think you'll see nuthatches, finches, cardinals or mockingbirds handling their food exactly like this.
That's because this food-holding technique is not at all something thought up by each bird as the occasion arises. It's an instinctual pattern of behavior shared by all members of several closely related bird families, two of which are the crow family and the chickadee/titmouse family.
Millions of years ago a now-extinct bird species, a common ancestor to both the crow and chickadee/titmouse families, was the first to use this holding-between-feet feeding strategy, and the predisposition to hold food between the feet was genetically passed on to later generations -- in the same way that today we see offspring of Sheepdogs just as predisposed to herd sheep as their parents, and descendents of toy poodles to be just as nervous and barky as their parents.
As the eons passed, our crow/chickadee ancestor's descendents dispersed over a large geographical area and its population fractured into subspecies, as the Song Sparrow is currently doing. Eventually those subspecies crystallized into many distinct species. Early during this process the family tree developed a major split down the center, just like many natural trees. On one side of the tree arose branches bearing species we now refer to as members of the Crow Family, and on the other side there appeared members of the family of chickadees, titmice and some others, and despite the outward dissimilarities of crows and chickadees, the unseen genes of these hundreds of species continue to register our single ancient, holding-between-the-feet evolutionary event .
So today as the crows chisel and caw and look around as crows are wont to do, I witness an evolutionary event echoing since deepest antiquity. Yet this echo remains a pure tone, and it is struck mid-course in a perfect musical score realizing itself among my Pecan trees.
YELLOW MULBERRY WOOD
One trench passes a mulberry tree and in cutting through some of the tree's roots I have been struck by how pretty its roots are. Their smooth bark is a pretty reddish purple, and the wood itself, at least when freshly cut, is a rich golden hue wonderful to look at.
M. Le Page Du Pratz, whom I introduced in the August 19 Newsletter, reported how the Natchez Indians used mulberry wood as a source for yellow dye. He mentioned how different dyeing techniques resulted in cloth with varying hues of yellow and gold. I can just imagine how handsome the Natchezes' garments must have been, how their golden robes must have shone as they stood in the light of their sacred sun, on the loess bluff overlooking the Mississippi.
Really I think the mulberries of this area must be something special, possibly as a result of centuries of careful culturing by the Indians. The Natchez also wove fine garments from mulberry bark, something easy to believe if you try to break a twig from a mulberry without cleanly cutting it. Very strong fibers hold the snapped twig in place and if you keep tugging at it, it's so stringy that it tears a long gash down the limb.
The fruits, however, are the most delightful thing about them. I'll tell you about them when their time comes...
If you are fascinated by the field of natural dyes, you might check out "A Primer on Natural Dyeing" at http://www.i-is.com/st.clairflats/wpdye.htm
LAST WEEK OF THE NATURAL YEAR
For, on Friday the Earth returns to a certain position during its yearly revolution around the sun where, from my local perspective here in the woods near Natchez, it appears that the most important of all annular cycles starts all over again. Ever since the Equinox of June 21, days here have been growing shorter. Of Friday the tide will turn, and then slowly on this side of the Earth's hemisphere we shall return to longer, brighter days. This is something I choose to celebrate.
Having chosen to identify with natural cycles such as the Solstice, and not with the usual holidays of the culture around me, it is easy to pass into yet another heresy.
That is, I simply do not recognize winters.
Friday's Solstice is the beginning of a long, blossoming SPRING. This spring later will merge into a long, busy summer, and that summer will mellow into a long, bounteous fall. And this time next year fall will once again give birth directly to spring...
Who decided that we must submit to the concept of "winter"? Winter is no less an illusion than anything else, so why put up with it? Already in November we were seeing signs of spring everywhere, and by now spring is hardly able to wait.
Having said this, now it is appropriate for me to thank each of you for subscribing to my Newsletter during this first year of its existence. Seeing and experiencing the world around me not only for myself but also for you has increased my watchfulness, and sharpened my senses. Just by being on my list, you have enriched my life, and this has been a great gift for me.
On Friday, if what I say here increases the chance that you will remember to reflect for a moment on the majestic shifting taking place as fall blossoms into spring, then that will be my season's gift to you.