NATCHEZ NATURALIST
NEWSLETTER:
August 10, 2003
BIRD TEENAGERS
Nowadays the birdworld is graced with a beautiful awkwardness. Tree shadows and
weed-jungles are rampant with the avian equivalent of teenagers -- fledglings of many
species on the verge of being adults. One moment a young Mockingbird misjudges his landing
on a twig, loses his grip and slips, fluttering hilariously as he struggles upright. This
same bird a few moments later gazes at the sky with perfect Buddha composure, clear eyes,
graceful lines, a burgeoning song in his heart.
Sometimes it's hard to figure out who some of these juveniles are. A completely brown
young'un looking like a sparrow with white wingbars and a forked tail turns out to be an
Indigo Bunting. Slender, pea-green birds the size of flycatchers are Orchard Orioles.
Teenage Summer Tanagers look almost the same, except for their thicker beaks and lack of
white wingbars. Young Ruby-throated Hummingbirds have no hint of a ruby throat, and young
Bluebirds are essays on drab speckledness.
Of course it all makes sense. These young birds need to be drab and well camouflaged
because of predators. Only next spring will bright colors become important to them, when
strutting and displaying before their mates. Now is their time to be both awkward and
plain, and in being so, remind us how beauty arises from simplicity.
*****
MINNOW EMERGENCY IN STREAM
We're needing rain here. During the last couple of weeks several substantial storms have
passed us by, but hardly a drop has fallen right here. This makes it a good time to walk
in Cooper's Branch, the little stream passing by the barn and eventually emptying into
Sandy Creek. Usually water runs in the branch and there's more than a few quicksand-like
places where you can suddenly sink knee-deep or deeper in mud and sand. But now the
stream's bed consists of hard-packed dry sand, with only an occasional pool of water.
In those isolated pools the "minnows" are gulping for air, and in some pools
already those silvery little fish are dying en masse.
I put the word "minnows" in quotations because it's one of those words the
meaning of which changes depending on with whom you are talking. Most folks think of any
small, plain-looking, silvery fish as a minnow, but ichthyologists say that, technically,
a minnow is a member of the Minnow Family, the Cyprinidae. The funny thing about that,
though, is that carp - even those 3 ft. long ones weighing 20 lb. or more -- are minnows,
because carp are members of the Minnow Family. Same with goldfish. Members of this family
are soft-finned fishes with teeth only in their throats. The Minnow Family is a huge one,
with over 300 species in North America. Therefore, when on Wednesday I plucked a dead
"minnow" from a drying-up pool, I had problems identifying it.
The only fish field guide I have is the small Golden Guide called "Fishes."
By comparing pictures in it I was able to figure out that my "minnow" was indeed
a member of the Minnow Family. Then on the Internet the best I could do was to find a page
called "Key to the minnow or carp family (Cyprinidae) of Canada." It provided a
good "key" to the species, with nice pictures of each. This illustrated key is
at www.fishbase.org/keys/questions.cfm?keycode=86
You learn a lot about a fish while "keying it out." I had to count scales
along the fish's lateral line, count rays in its dorsal fins, and notice that its mouth
opened upward, not downward. When it came to figuring out on which side of the fish's body
its intestine made a loop, I quit -- though I was glad to know that in the world of fish
such details matter. If you want to see what my fish looked like, look at the Sand Shiner
(I'm not sure what it's intestine does) at www.biology.ucok.edu/SelmanLL/SelmanFishPage/images/traders2/pimephales2.jpg
The best I could determine, my dead "minnow" was one of several
"shiner" species of the genus NOTROPIS. My nature-photographer friend Jerry
Litton in Jackson tells me that about ten similar species occur throughout the Homochitto
Basin, so until he comes down to find out on which side of the body the intestine makes a
loop, I'm satisfied just to call it "a shiner."
*****
TALL IRONWEED HINTS AT FALL
In certain weedy spots with moist soil, the six-ft- high (2 m) Tall Ironweeds, VERNONIA
GIGANTEA (also known as V. altissima) are erupting with deep reddish- purple composite
blossoms. To a wildflower person that means nothing less than late summer is becoming
early fall. You can see a spray of Tall Ironweed flowers at www.marysplantfarm.com/_photos/wildflowers/iron_weed.jpg
The vast majority of wildflowers in our area either blossom during the spring or fall,
with very few species being thought of as "summer bloomers." If I had to list
our most characteristic fall wildflowers I'd mention goldenrods, asters, eupatoriums and
ironweeds. The golden yellow of a few goldenrods also is tentatively appearing in certain
pastures and fencerows, so when I see both goldenrod and ironweed in one glance, I am
visited with fall-time nostalgia.
As with goldenrods, asters and eupatoriums, several ironweed species are known. Just
within the US Southeast about 15 species are recognized, and some of those are highly
specialized. For example, V. lettermanii grows only on gravel bars and in the cracks of
chert rocks in the drainage area of the Ouchita River. V. blodgettii sticks to low
pinelands in southern Florida. However, our V. gigantea pops up everyplace from weedy
pastures in Vermont to thin woods in eastern Texas, and prairies in eastern Kansas. It's
an easy-going species, very pretty, and always a pleasure to see.
On the Internet I read that this species has been used medicinally "as a bitter
tonic to stimulate the appetite & to purify the blood." There must still be some
folks needing their appetites stimulated because at one site selling medicinal herbs they
are offering dried ironweed root at $14/lb.
I've read that Ironweed gets its name from the strength of its stem. Maybe that's
right, for a fairly durable paper can be made from Ironweed stem fibers. You can see what
such a paper looks like at http://ginpetty.com/pix_p2002_07/ironweed.jpg.
To learn more about the paper-making process, go to http://ginpetty.com/paper/p%5F2002%5F07.htm
and use your search function to find the several occurences of the word
"Ironweed."
*****
57 BARN SWALLOWS ON A WIRE
Wednesday on the way to the mailbox I noticed a long line of Barn Swallows perched
shoulder-to-shoulder on the power lines along the highway. There were 57 of them, more
than usual.
Most small songbirds, at least during the summer, feed in territories they defend.
Swallows and swifts, however, tend to congregate where food is abundant. Moreover, since
the density of flying insects can vary over an area on a daily or even hourly basis,
swallows and swifts use one other as clues to finding food. Sometimes over the big
Loblolly field next to the barn I see not only Barn Swallows but also Chimney Swifts,
Purple Martins and Rough-winged Swallows. (When they disappear at dusk, then the bats come
out... )
Among bird ecologists there's a general rule that states this: "Stable food
resources and defensible areas promotes territoriality in a species, but unstable food
resources and indefensible areas promote coloniality." Thus the swallows' colonial
habits are to be expected.
It's generally thought that coloniality has three main advantages:
- attacking predators can get confused if there are too many birds
to focus on
- the larger the flock, the less chance any specific individual will
be chosen by a predator
- the more birds there are, the more likely that one of them will
notice an approaching predator
It must be a beautiful time of the year for swallows -- feeling the need to be with
others and being able to do so, as new family groups join the flock hearing new accents
calling around you, seeing new flying tricks certain newcomers are capable of, having new
information about surrounding territory added to the flock's knowledge-base... and who
knows what else?
*****
DRAGONFLY WING VENATION
Newsletter subscriber Hillary Mesick sent me a fine scanning of a dragonfly he found down
on the Mississippi coast. The veins in the insect's wings showed up so well that I used
the image to talk about wing venation at the top of my dragonfly page on the Web. You can
see that image at www.backyardnature.net/odonata.htm
Wing venation is important when identifying dragonflies because vein patterns differ
from species to species. The main veins even have their own names, such as
"arculus," "antenodal cross veins," and "nodus."
At this time of year when dragonflies are so active we can have lots of fun identifying
them using a book called "Dragonflies Through Binoculars: A Field Guide to
Dragonflies of North America." This book can be reviewed and purchased through
Amazon.com via a link just down the page from the wing-venation image at the above
address. You'll be amazed at how many dragonflies and damselflies there are -- some 420
species in North America -- and the beautiful variety among them.
*****
SCRAMBLING WALKINGSTICK
While sitting quietly in the woods I heard something scrambling through dry leaves. It
sounded like a lizard in a hurry and at first glance that's what I thought it was, except
that it sure was a skinny one. The running thing ended up on the base the of a tree trunk,
then froze, and I could see that actually it was the insect known as a Walkingstick.
It was a good-size one, too. I went to measure it just so I could tell you. From the
tip of its head to the tip of its rear end it was exactly 5 inches long (12.5 cm). From
the tip of its antennae to the tip of its rear end it was 7.6 inches (19 cm). I managed
such exact measurements because the insect remained perfectly still, effectively
camouflaging itself as a gray twig. You can see a walkingstick like the one I saw, except
that mine was gray instead of the golden hue in the picture, at http://insects.ummz.lsa.umich.edu/Images/Orthoptera/stick.jpg
Walkingsticks in this area can get even larger than this -- with bodies up to 6 inches
or more. The size wasn't what caught my attention about this critter. What really
interested me was that this was the first time I'd ever seen one running so fast and
noisily. Nearly always one sees them perfectly still, or moving lethargically along a
stem. In fact, one of my insect field-guides describes them as "so ambitionless that
they move very slowly." The one I saw Wednesday afternoon, at least for about three
seconds, was a perfect hurricane of movement. (Admittedly he was moving downslope on loose
leaves, so maybe that helped.)
My family taught me that walkingsticks can sting you fatally. Sometimes they're called
"Devils' Darning Needles." I can recall vividly as a child seeing one on a tree
limb and shivering with excitement at having such an awful creature so near me.
But of course walkingsticks don't sting at all. They are peaceful vegetarians and our
species doesn't even have wings. Except for their size and similarity to a dead stick,
they could hardly be less exciting. They are, in fact, fairly closely related to
cockroaches.
*****
GRAPE ETHICS
On National Public Radio they are presenting a series of segments on the subject of
ethics. On Tuesday they explored the question of how unethical it would be -- if at all --
to steal a single grape in a supermarket. Some people insisted that it wasn't unethical at
all while most took ambiguous positions saying that it depended on the circumstances. Only
the professional ethicist asserted that taking even one grape was unethical. He further
explained that in classical times people based their ethics on what was good or bad for
society while today the ever-more-dominant paradigm is "It's OK if I don't get
caught."
In my opinion, an eco-ethical equivalent of the pilfering of a grape is the leaving on
of lights when they are not needed. That's because we all understand the following
connections: Burning lightbulb --> power plant --> burning coal or oil, or nuclear
power --> pollution or radiation --> death of plants and animals.
The ethicist on National Public Radio made an elegant point: He said that in classical
times people cared about daily ethics not because they hoped to gain material reward from
it, but because they felt that by being ethical, even in tiny, grape-stealing ways, it
made them and their society stronger.
In this same week when it was announced that Los Angeles's air quality is worsening for
the first time in many years, and our president nixed higher fuel-use standards for cars,
and continues to encourage suburbanites to buy gas-guzzling SUVs, how refreshing to have
someone remind us that the ethical use of a single grape (or a single lightbulb) can have
far- reaching consequences for both society and individuals. |
