from the woods near Natchez, Mississippi, USA
February 1, 2004
SOLAR SATELLITE DISH
Last week the property owner and I decided to try making a solar cooker from an old, abandoned satellite dish a neighbor offered us. It was one of those eight- foot-wide, black structures from the early days of satellite TV reception which around here clutter people's yards like old cars. We removed the metal webbing from between the dish's radiating ribs and, with the help of neighbor Karen Wise, replaced it with triangular sheets of aluminum cut from a 50-ft roll of "flashing" sold in a local hardware store for $27.50.
I inaugurated the dish at noon last Sunday, seeing if it could fry a huge, double-yoked egg from one of Karen's hens. Not only did the egg fry, it did so in ten minutes.
Then, where the light focused, I set a jar of water with a thermometer in it. I watched as the dial gradually rose to 180°F (82°C), at which point I removed the thermometer because its scale went no higher. At that point tiny bubbles were forming briskly at points on the jar's bottom, indicating that the water was almost boiling.
The inaugural test ended with my baking a full skillet of cornbread in about half an hour. The cornbread was in some respects better than what I fix over the campfire, since there was no charring. Later tests showed that I could indeed burn cornbread.
Reflecting on the new cooker, Hillary on the Mississippi Gulf Coast sent some figures:
"Average solar power is about 600 watts per square meter at Earth's surface. It can be as high as 1000 watts. If that's an 8' dish then that's about 4.5 square meters. So that's about 2.7 KW of power if it was 100 percent efficient... That can cook your Twinky"
Hillary also suggested that another way to look at it was to remember those times as kids when we focused sunlight through magnifying glasses onto ants, resulting in the ants' instant cinderization. Just think of what a magnifying glass eight feet across could do.
You can see the dish and read more about it at my new "Constructing a Solar Cooker From an Abandoned Satellite Dish" page at www.backyardnature.net/j/solardsh.htm
Other solar-cooking information and ideas are available at "The Solar Cooking Archive" at http://solarcooking.org/
BLUE JAY COURTSHIP FLOCKS
Nowadays on warmish, sunny mornings, sometimes I hear Blue Jays making strange rattle-calls. If I watch the spot where the calls originate eventually I see a flock of five to eight jays flying away. These small flocks and rattle-calls are part of the jays' early- season courtship behavior. If you live outside Eastern North America, you should take a look at this beautiful, interesting bird, for it's very common and well known in our region. A picture of one exactly as it appears at an average birdfeeder is at http://members.cox.net/birdingnla/blue%20jay%20%2012_07_2002_a_%20062_small.jpg
During fall, Blue Jays, CYANOCITTA CRISTATA, join into large, roaming flocks evenly divided among males and females. When cold weather arrives they break into smaller flocks of maybe four to six birds. With the first stirrings of spring, Blue Jays form "courtship flocks" consisting of three to ten birds moving about as a group in an area of one-quarter to a square mile (0.65 - 2.6 ha). Though males and females are identical, it's believed that courtship flocks consist of one female, with the rest being males. The female basically leads the males around, whether it's shifting from the middle to the top of a tree, or flying across a field.
The question at this time of year is then whether a particular flock is a general cold-weather, mixed-sex flock, or a newly constituted courtship flock. To decide, you must look for courtship behavior.
One typical piece of courtship behavior is the "bobbing display," which often is accompanied by the "toolool-call" or the "rattle-call." Bobbing consists of the bird quickly and repeatedly raising and lowering its whole body by extending its legs. The "toolool-call" is a two-part, monotonal, bell-like call, and the "rattle-call" is a dry, nonmusical rattle.
Therefore, since I'm hearing the rattle-call, I'm assuming that my little flocks are courtship flocks.
Once we read about these behaviors and calls, often we think, "Oh, I've seen that! I've heard that!" It's just that we need to have someone draw our attention to these things, and to explain what they mean. Several excellent books, particularly those by Donald Stokes, focus on bird behavior. These book can enhance our backyard birdwatching enormously. To review such books, check out the "Bird Behavior" section of my "Birding Books" page at www.backyardnature.net/amazon/birding.htm
CEDAR WAXWINGS DOING ODD THINGS
Speaking of bird behavior, Cindy in northeastern Michigan sent me a wonderful picture she took of a Cedar Waxwing during a heavy snow. The bird is shown with its head thrown back and its beak wide open. When Cindy explained that it was catching snowflakes I replied that surely it was disgorging fruit pits, or seeds, after having a big meal of something like Hackberry fruits. Often I've seen waxwings eat several such fruits, then fly to a nearby perch and as their crops removed the fruits' fleshy parts the birds would "cough up" the hard pits and let them fall onto the ground. However, Cindy replied that "they were definitely catching snow because some were 'pecking' at the air. No pits were spit." You can see Cindy's waxwing picture on my "Pre-Programmed & Learned Behavior" page at www.backyardnature.net/birdlern.htm
Right after receiving that picture, Leona in Missouri wrote "I have been noticing rustlings in the dry oak leaves, rustlings when there is no wind, and close scrutiny discloses cedar waxwings tucking themselves into curled oak leaves. To keep warm? To make interesting noise? Who could guess. Last week when I was working in shirtsleeves and it was warm, I was surprised by a whole flock of them flying out of a brown-leafed oak. Now, (it was 4 degrees this morning and 20 degrees now) as I trudge back along the ridge with my bucket of sunflower seeds for the chickadees and nuthatches and titmice, downys and hairys and yellow bellied woodpeckers, I find oak trees with leaves that rustle and move and they are full of waxwings. So temperature does not seem to be the answer."
Around here regularly I spot high-flying waxwing flocks of 10-20 birds, issuing thin, high-pitched, quavering calls as they pass over. They fly in close formations and it's something to see how quickly each bird reacts to its neighbors' changes of course. The flock behaves like a single organism, a compact but diffuse unity perfectly conscious of itself.
Throughout the year I hear Barred Owls hooting but nowadays they seem to be calling more rambunctiously than usual, even during days. Probably this is because it's their nesting season. Stephanie in Tennessee also reports hearing owls, though she seems to have Great Horned Owls, not the Barred Owls so common around here, since she reports seeing a "dark shape with the ears like horns," and our Barred Owls don't have ear tufts. In general, Barred Owls are more southern and favor bottomland woods, while Great Horneds are more northern and upland-preferring. You might like to compare the hoots made by Barred Owls with those made by Great Horneds. Below, the first link lets you hear a Barred Owl, the second a Great Horned:
The books say that Barred Owls ask "Who cooks for you, who cooks for you-all?" Calls of Great Horned Owls are described as consisting of "3 short hoots and 2 long hoots." However, owls don't always stick to their scripts. I've heard some outrageous screaming, yelping and generally raunchy carrying-on committed by Barred Owls who didn't seem the least interested in who was cooking for whom. Stephanie nicely described her nesting owls' non-book-form calls this way:
"This morning I set out from my house and could hear him already (it's about a half-mile away) deeply h-hooing, four hoots. While I stood by their hollow, I got to hear the mother's reply from inside the tree. He sat in a tree in the back yard h-hooing every couple of minutes, and she'd answer him very softly every third call or so: about seven little short-long hoots like morse code."
As with owls, throughout the year I hear Coyotes but nowadays their calls are more noticeable than usual, and probably it's because of the same romantic reason. I'm not hearing the classic, long-drawn-out howls we associate with cowboy movies, but rather brief outbursts of uninhibited, undignified yelping. I can't find audio files on the Internet featuring such yelping, but just for the fun of it you can hear some howls with a bit of coyote barking at www.tpwd.state.tx.us/images/kids/sounds/chowls.wav
The classic, long-drawn-out howl is known as a "location howl." It's used by lone coyotes trying to locate other members of the pack. I've seen reference to about 33 distinct "coyote vocalizations." The best I can figure out, the yelping I'm hearing fits into the catch-all category known as "pack communications," described as "A kind of yip/howl 'talk' among members." Most vocalizations are better defined. For example, the "greeting call" is described as a "yip/howl happy vocalization that welcomes others back to the pack." The "alarm call" is a "shrieking repetitive bark." You can see an annotated partial- list of coyote vocalizations at www.southwestwildlife.org/sounds/coyotevocal.htm
Though I often hear coyotes not long after dusk or right before dawn, I seldom see them. I do find a lot of their scat, which is about the size and shape of a regular dog turd, but it's composed largely of hair and bones. Occasionally as I'm jogging in dawn's twilight I spot a coyote trotting across the field beside me, moving in a broad arc to keep a respectable distance. This way I've discovered his secret hole where he squeezes beneath a fence. You wouldn't notice the hole if you weren't looking, but once you know it's there, then you can see that a well-worn path leads to it.
A basic introduction to Coyote life can be found at www.desertusa.com/june96/du_cycot.html#anchor327144
BRITISH SOLDIER LICHENS
The property owner has a digital camera and during his recent visit he photographed a ¼-inch high (6 mm) British Soldier Lichen growing atop a fencepost next to the barn. By tradition, the Latin name of a lichen is the name of its fungal component. The fungus part of the British Soldier Lichen is Cladonia cristatella, while the alga part is known as Trebouxia erici. On my lichen page you can both learn the basic facts about lichens, and see the fine digital picture of our British Soldiers (second picture down), at www.backyardnature.net/lichens.htm
At the top of that page one of my drawings shows how lichens are composed of two distinct organisms, a fungus and an alga. The drawing portrays fungal hyphae enveloping algal cells.
A British Soldier Lichen was the very first lichen I ever identified, because its bright red spore- producing top makes it so distinctive. I still remember the frigid January morning in Kentucky, back in the 1960s, when I discovered it, a beautiful little colony on the ground in a long-abandoned field overgrown with redcedars. To this day I associate the odor of redcedar with British Soldier Lichens.
Knowing the names of things is like that: The name gives you a mental pigeonhole. Then, into that pigeonhole, during the entire course of your life, you can insert all kinds of information, memories and associations. On the June day last year when I first came to this new location, one of the first things I noticed was the British Soldier Lichens appearing in the picture, and as the day's suffocating heat and horsefly hoards pooled around me, my mind for an instant thrilled to memories of a long-gone frosty January morning in Kentucky smelling of redcedar.
WITH A SONG IN MY HEART
When I added Cindy's waxwing picture to my page on programmed and learned behavior in birds, I took the opportunity to review my text there. Here's something I read about White-crowned Sparrows (occasionally showing up around here during winters), which got me thinking:
"Even when newly hatched White-crowned Sparrows are kept where they can't hear any kind of bird song, when they're about a month old they begin singing simple notes. This bird babble, known technically as subsong, continues for about two months. When the birds are about 100 days old, their subsong 'crystallizes' into a form that thereafter doesn't change much. The singing of White-crowned Sparrows of this age who have never heard other birds of their species sing is not nearly as rich and pleasant to hear as that produced by birds who have grown up hearing their own species sing. Nonetheless, experienced birders can definitely hear the White-crowned Sparrow element in their song."
Think of it: The power of the genetic code is so great that it enables a bird to sing its song, even if the bird has never heard that song before. Melodies can be passed through the dimension of time encoded in the genomes of living things.
Further down that page I make the point that when a female Canvasback duck is about a year old and builds her first nest, she builds a nest exactly like all other Canvasbacks, even if she has been kept in isolation, and couldn't have learned Canvasback nest-building technique from other ducks.
These facts cause me to wonder to what extent the songs and "nesting instincts" in our human hearts are genetically fixed. Just how much of each of us is any more than what our genes say we have to be?
That's one question that nudged me into this hermit- naturalist's life. The same impulse that made me a Dixieland-loving trumpet player for most of my life sets me to improvising on the fixed melodies inscribed inside me by my genes, and this seems like a good stage on which to try it.