November 24, 2013
DEER ANTLER VELVET
The valley of the little Dry Frio River is overpopulated with deer. Mostly there's native White-tailed Deer, but also Axis Deer from Asia are very common, and from time to time you see European Red and Fallow, and other deer and deer-like species escaped from local ranches who sell hunting rights for shooting "exotic game."
Most of my car-driving neighbors have hit one or more deer, and it's common to see dead deer beside the road. This week a large male, six-point Axis Deer has been decaying along my jogging route. I was interested in the thick "velvet" covering his antlers, a small portion of which can be seen at http://www.backyardnature.net/n/13/131124vm.jpg.
Antler velvet is hairy skin, not just hairs, covering actively growing antlers. Antlers are regarded as the fastest growing of all mammal bones, which explains why antler velvet skin is so richly supplied with blood veins, which supply oxygen to the antlers. Once an antler has reached full size its velvet is lost and the antler bone dies, resulting in the mature antler.
Mature bucks whose antlers have stopped growing spend a lot of time and energy scraping their antlers on the trunks of young trees, removing the velvet. The scraping often severely damages or kills the tree. Hunters look for such trees, calling them "buck rubs."
If you Google the keywords "deer antler velvet," mostly you get links to businesses selling deer antler velvet, because deer antler velvet is big business. New Zealand ships tens of millions of dollars worth of velvet to Asia and the US each year. A National Geographic page refers to deer antler velvet as "essentially a growth hormone called 'insulin-like growth factor 1,' or IGF-1."
Growth hormones are given to young people with stunted growth, but the main use of them nowadays seems to be by athletes and bodybuilders because some research shows that IGF-1 may be effective in healing certain cartilage and tendon injuries. Deer antler velvet, being natural and for thousands of years used by various cultures for various purposes, is an unregulated source of IGF-1. Still, IGF-1, thus deer antler velvet, is on the National Football League's list of banned substances.
DEER BUCK RUBS
"Buck rubs" -- where male deer rub their antlers against tree trunks to remove the velvet -- are commonly seen here in the fall. A buck rub on a young Texas Liveoak growing along the little Dry Frio River is shown at http://www.backyardnature.net/n/13/131124br.jpg.
How do you know that this trunk damage isn't caused by a porcupine or feral pig? When porcupines debark trunks they leave tooth marks, which aren't seen in our picture. Debarking caused by feral pigs is more similar because they also damage the tree by rubbing on the trunk to remove mud and parasites. However, pig rubs tend to be near wallows, where they wallow in mud, so often their rubs are dirty, plus often you can find stiff pig hairs, or bristles, in cracks of the rub tree's bark. Pig bristles may be of a different color than deer hairs.
If you watch a buck while rubbing, you'll see that he's doing more than rubbing velvet off his antlers. Bucks generally rub the bases of their antlers and their forehead skins against the trees, and may stop to smell or lick the rubbed area. This happens because buck rubs serve as a buck's calling card for potential mates, and as a challenge to other male deer. The buck's scent is left on the trunk, the odor being produced by special glands. Dr. Jon Gassett conducted a chemical analysis of volatile chemicals associated with a buck's forehead region and identified 57 different compounds.
This raises the question of whether deer can recognize by the odor the individuals who marked the rubs. Also, it's been noticed that following a sparring match between two bucks the "loser" frequently licks the forehead region of the dominant animal.
An article in Field & Stream Magazine says that individual bucks make from 69 to 538 rubs each year, with dominant bucks averaging 300 or more. One study found older bucks making more than 1200 rubs during the roughly 90 day rubbing period, which translates to about 15 rubs per day! Dominant bucks tend to make many more rubs than subordinates, so a good guess is that when dominant bucks mark their range with rubs they're not only announcing their presence but also their dominance.
DOVES AT PHRED'S FEEDER
Neighbor Phred sent another picture of doves at his feeder, this time the White-winged Doves shown at http://www.backyardnature.net/n/13/131124dv.jpg.
Beyond the fact that it's a pleasure seeing the birds' faces so alert and curious, it's nice to notice how blushes of blueness spread from their beaks to around their eyes, and how neatly the black "whiskers" ornament their cheeks.
The birds on the right and center are puffing up their necks, which is something males do to attract females
AQUATIC PILL BUG
I'm used to finding pill bugs -- also called roly polies, sow bugs, woodlice and other names -- under moist logs, in dank basements and the like, but several turned up this week on the undersides of rocks lying in the Dry Frio's trickling, shallow water. You can see one rolled into its ball-like defensive position, on the undersurface of a rock just taken from the water, at http://www.backyardnature.net/n/13/131124pb.jpg.
I shouldn't have been surprised to find an aquatic or semi-aquatic pill bug because pill bugs are crustaceans, like lobsters, crabs and shrimp, who are aquatic. In fact, pill bugs are the only crustaceans to have colonized land with much success. As such, they have not evolved the cuticle waxes that waterproof the exoskeleton exteriors of insects and spiders, and thus experience serious problems with drying out.
While I had a cooperative pill bug in hand I got a nice picture from the side clearly showing how the top protective plates are formed. You can see this at http://www.backyardnature.net/n/13/131124pc.jpg.
A shot of the critter's undersurface was even possible, seen at http://www.backyardnature.net/n/13/131124pd.jpg.
That picture shows several features of the pill bug's basic anatomy. The antennae at the far left in the picture are bent at sharp angles. The body consists of seven main trunk segments, each bearing legs. Behind those seven main segments -- to the right in the picture -- are six smaller ones, known together as the pleon. Pleon segments bear greatly modified legs, of which the first five pairs are known as pleopods, which form a set of overlapping, gill-like structures. To survive, a pill bug's pleopods must be kept moist. Studies show that critical amounts of water are both lost and absorbed through the pleopods. In some pill bug species the pleopods' covering, or cuticle, is in-folded, creating whitish, branching tubules that serve as "pleopodal lungs."
In the above photograph at the far right -- the pill bug's rear -- you can see two, tiny, cylindrical items like little fingers pointing from beneath the last scale toward the picture's right edge. Those are uropods. I read that pill bugs can take up water through their uropods and channel it through grooves along the sides of their bodies to their mouths, and also I read that uropods are sensory and defensive in function; I'm unsure how to reconcile those statements.
By the way, the ability to roll into a ball is to be able to "conglobate." Our first picture, of the rolled-up pill bug, shows a conglobating individual.
Sometimes when I step into the little greenhouse with its burgeoning raised beds of mustard and turnip greens, bok choy, collards, chard and more, a flurry of tiny white moths rises from the beds, settling on the greenhouse's white-plastic sides or back into the herbage. With a body length of only about ¼ inch (6mm), when these very small moths land you can see that they are very slender and possess long, stiff, minutely banded, forward-projecting antennae, as shown at http://www.backyardnature.net/n/13/131124mt.jpg.
This is the Diamondback Moth, PLUTELLA XYLOSTELLA, one of the most important pests of Mustard-Family, or "cruciferous," crops in the world. My mustard and turnip greens, bok choy, and collards are all cruciferous. Probably native of Europe, Diamondback Moths were first observed in North America in 1854, in Illinois, spread to Florida and the Rocky Mountains by 1883, and were reported from British Columbia by 1905. Today they're found worldwide. In the picture you can see that the back edges of the moth's wings bear fringes of slender, hairlike items, and that at the moth's rear the fringes turn upward, like an airplane's vertical tail fin.
The moth's larval stage, a green caterpillar, does the damage in gardens. Though small, they can occur in such numbers that they leave nothing in a bed of greens but skeletonized leaves -- something that happened to our crop last year, and may happen again. We have a picture of one at http://www.backyardnature.net/n/13/130310cb.jpg.
Damage by Diamondback Moth caterpillars is hard to control. During the 1980s they developed resistance to pyrethroids and soon afterwards virtually all insecticides became ineffective on them. Normally the organic gardener thinks of Dipel, containing the bacterium Bacillus thuringiensis, which gives caterpillars a fatal illness. However, Diamondback Moth caterpillars have become the first insect found to become resistant to biological control by Bacillus thuringiensis in the field. In the North the species dies back each winter from the cold, but down here our winters aren't cold enough to wipe them out.
So, each morning when I enter the greenhouse and the little flurry of moths rises to greet me, the thought I always have is that this is the beginning of something that before long will affect mankind profoundly: The pest and disease organisms that for decades have been held in check by chemicals, antibiotics and the like, now are acquiring resistance.
I can only imagine what changes will be wrought when resistance is acquired not only by Diamondback Moths but also the organisms that plague all our major crops, and the microbes that affect us humans, as well.
All year I've been waiting for a certain aquatic plant to produce flowers so I could identify it, but so far I'd seen none. The completely submerged plant's stems grow up to a yard long (1m) and in running water trail downstream. In the Dry Frio's water it's always heavily coated with muddy marl, as seen next to a fallen tree trunk at http://www.backyardnature.net/n/13/131124pq.jpg.
Thinking that this late in the season some trace of flower or fruit I'd overlooked might be found, I waded into a mass of them and examined numerous stems before finding exactly what I wanted, and I was surprised. You can see what turned up at http://www.backyardnature.net/n/13/131124po.jpg.
A spike of flowers and fruits tip the stem. A close-up of the spike is at http://www.backyardnature.net/n/13/131124pp.jpg.
Earlier this year we saw a very similar plant, an aquatic bearing thick, stem-tipped spikes of tiny flowers, the Illinois Pondweed, Potamogeton illinoensis, shown at http://www.backyardnature.net/n/h/pondwee4.htm.
This week's plant -- obviously a second species of pondweed -- differs by producing no parts that rise above the water's surface, and its leaves are wavy-margined.
I've seen this species before, back in southern Oregon's Siskiyou Mountains, but there it grew in clear water and wasn't coated with marl. Back then we identified the plant as the Curled Pondweed, POTAMOGETON CRISPUS. You can see Oregon's cleaner specimen and a close-up of its unusual flowers at http://www.backyardnature.net/n/h/pondwee2.htm.
Apparently our Texas plants are likely to be smothered beneath layers of marl or plain mud, because here people often call Curled Pondweed "Curly Muckweed."
From its occurrence in both Oregon and Texas it's clear that this plant has a large area of distribution. In fact, Curled Pondweed is an invasive from Eurasia, Africa and Australia, but was introduced into the US in the mid 1800s. In the US it appears to be most common in cooler areas such as the Northeast and higher elevations in the West. It's common enough in Texas for Texas A&M to provide a webpage focusing on getting rid of it. There it's written that "Curly-leaf pondweed can be removed by raking or seining it from the pond but will reestablish from any remaining roots." It continues saying that a pond can be fertilized to produce an algal bloom, which prevents the establishment of most bottom-rooted aquatics such as pondweeds.
Curled Pondweed's success as a weed largely rests on its ability to reproduce vegetatively and its capacity to thrive in many kinds of water. It reproduces vegetatively not only with broken stems but also by "turions," which are specialized overwintering buds that survive when the rest of the plant deteriorates. In our pictures you can see that our plant already is falling apart in places.
RED CHARD'S PIGMENT
We have a little greenhouse 10 x 10 feet square (3 x 3m) consisting of an aluminum frame covered with white plastic. Inside it, raised beds currently produce lush crops of mustard and turnip greens, bok choy, spinach, lettuce and chard. The white plastic doesn't admit as much light as I'd like, causing plants to grow a little spindly and thin-leafed, but that also makes the leaves softer for eating.
The chard is so pretty that I feel good just sitting next to it and feasting my eyes on its green leaves with their bright red stems and veins. When I see put my face right down among the stems, I see what's shown at http://www.backyardnature.net/n/13/131124ch.jpg.
Some chard cultivars have red stems and veins while those of others are mostly white, green or yellow. The red-veined ones are prettier on the plate and thus more popular with most gardeners, though older green forms tend to out-produce the colorful hybrids.
I don't mind trading higher chard production for the pretty redness of red-stemmed chard cultivars, however. Chard is extraordinarily nutritious to begin with, and now it's known that red chard's redness is produced by a class of pigments that adds even more health benefits. Red chard's red pigment is produced by a class of pigments called betalains. If you've heard about the nutritional benefits of red beet juice, you've heard of the virtues of betalain pigments. Red garden beets and chard are cultivars of the same species, BETA VULGARIS, so betalains are behind the redness of both red beets and red chard.
Mainly, betalain has been shown to be a powerful antioxidant proven to prevent cardiovascular disease in humans, and certain studies suggest it may be beneficial in cases of cancer, osteoporosis, and neurodegenerative disease. Much more on the benefits of betalain is at http://www.whatarebetalains.com.
Another reason I like having betalain pigment showing up in my chard is that among flowering plants betalain occurs only among the ORDER of plants known as the Caryophyllales, which includes such closely related plant FAMILIES as the Amaranth, Portulaca, Cactus, Four-o'clock and Pokeweed Families. Chard belongs to the Amaranth Family.
The assumption is that about 110 million years ago -- during the Cretaceous Period when North America and Eurasia still formed one big landmass populated by the great dinosaurs -- a primitive plant from which all current members of the Caryophyllales arose began producing betalain pigment, possibly because of a genetic mutation. Now that plant's descendents, from amaranths to cacti, have inherited that trait. In the Caryophyllales, betalains take the place of anthocyanin pigments. So far it's not known why this group of plants produces betalains, but there's some evidence suggests that betalains may have fungicidal properties.
Last week we had our first frost, which didn't phase garden plants like parsley and mustard greens, but which killed basil and tomato plants, and severely damaged such plants as my neighbor Phred's ornamental Castor Bean plant, whose pitiful curled and blackening leaves are shown at http://www.backyardnature.net/n/13/131124fr.jpg.
Cold temperatures kill in several interesting ways.
One straightforward manner, intracellular freezing, occurs when the sharp angles of ice crystals formed inside cells damage the cell's protoplasmic structure and puncture cell membranes.
Extracellular freezing takes place because between cell walls water is relatively pure, so it forms ice at the freezing point. However, water inside cells contains dissolved salts, sugars, enzymes, etc., which act as "anti-freeze." As ice crystals form between cells, water inside the cells is drawn out through the cell walls, which causes the cells to shrink. The resulting pressures and stresses on the tissue may cause cell walls to break, killing the cells. Also, so much water may be drawn from the cells that they may stop functioning because of dehydration. It's not by accident that soon after an herbaceous leaf suffers frostbite it becomes crinkled and stiff, as if from lack of water.
Nowadays when I jog before dawn the Moon prettily lights up the landscape. Even when there's no Moon and a heavy overcast, it's light enough to see the road, so with moonlight everything is etched in sharp detail. What a pleasure to breath deeply the moist, chill air, pat, pat, pat, my shoes on the pavement.
Often on these moonlit, pre-dawn runs one, two or more packs of Coyotes yelp along the route, and some sound close by. I say yelping instead of howling because their call isn't the stereotypical yaooooooooooo of cowboy movies, with the lone Coyote atop a hill with his head thrown back, silhouetted by the Moon. These are crazy sounding yelps and yeeps, sounds you'd expect from a bunch of drunken teenagers playing as if they were Coyotes.
I mentioned the coyotes to my friend Bob in northern California who replied, "They have been known to take pet dogs right off the leash when people are taking Fluffy out for a walk, and have attacked small children. Los Angeles has a huge coyote problem and San Francisco is working its way up to one." Sometimes when the packs are real close, the hairs on the back of my neck stiffen, despite being convinced that they won't attack me.
In fact, the main feeling I get from Coyotes along the pre-dawn road is something approaching awe. It has to do with a natural paradigm at the heart of my spiritual belief system.
For, I visualize the Universe as blossoming from the Big Bang, first all the atoms, molecules and subatomic particles over time gathering into myriad galaxies, then life arising at least in our galaxy -- and surely throughout our galaxy, and all the billions of other galaxies, too -- and eventually out of life arose mentality, all the insightfulness, feelings, inspirations of which thinking beings are capable.
So, from the Big Bang arose an unthinkable large, bouquet-like, perpetually evolving Creation, and it's a Creation evolving toward higher and higher states of sophistication, ever more diversity, ever more interrelatedness of parts, ever more exquisite thinking, feeling and refined sense of esthetics.
Seeing this, it appears that the Universe evolves toward feelings, and along the road on my pre-dawn, moonlit jogs, Coyotes express some part of that Universal feeling with more passion and fluency than I'm accustomed to in everyday life. Their yelping in the moonlight is nothing less than a physical manifestation of part of the very spirit of the evolving, blossoming Universe.
But, of course, you can say that about everything. Everything manifests the Evolving Spirit. And all us thinking, feeling, sentient beings, it seems to me as I run in the moonlight, are like nerve endings of the Creator of all this. So, it's my job to be as alert, aware and receptive as possible, and being thrilled by the calls of coyotes at dawn is a good way to start any day.
FEATURED ESSAYS FROM THE PAST:
"Wind Singing" from the March 11, 2012 Newsletter, at http://www.backyardnature.net/n/p/120311.htm
"Warming in The Sun" from the January 17, 2010 Newsletter, at http://www.backyardnature.net/n/p/100117.htm
Best wishes to all Newsletter readers,
All previous Newsletters are archived at http://www.backyardnature.net/n/.