Issued from the valley of the Dry Frio River on the
southern slope of the Edwards Plateau, northern
Uvalde County, southwestern Texas, USA

February 3, 2013

A persistent peeping arose from the screened-in back porch so I went to see what it was. A robin-size bird had entered through a door left ajar and now couldn't get out. You can see a picture of the upset bird, a little grainy because of the porch's dim light, at http://www.backyardnature.net/n/13/130203tw.jpg.

This is one of those birds whose nondescript plainness is so manifest that the lack of a good field mark is itself a good field mark. The bird is all brown, except that the brownness sort of curdles on the chest, plus there's a flush of rusty reddishness on the crown and beneath the tail. Otherwise, it's just the quintessential medium-sized, brown bird.

In the old days I called this bird the Brown Towhee. However, because the Brown Towhee species always was recognized as displaying a good bit of variation throughout its range, and because of the experts' usual taxonomic persnicketiness and the advent of genetic sequencing, the old Brown Towhee species has been abolished. The Pacific Coast population has been split off to form the California Towhee, and birds we have here and in upland central Mexico are now known as Canyon Towhees. Earlier the Brown Towhee's scientific name was Pipilo fuscus, but now most literature calls our population MELOZONE FUSCA. Most authorities place the species in the Sparrow/Bunting family, the Emberizidae, but some assign it to the Finch Family, the Fringillidae.

Whatever name you use, this is a fine little bird. If you're familiar with the Eastern and/or Spotted Towhees of broader distribution in North America, you know that those species often hang around suburban homes and like to get in shadowy places such as beneath hedges and scratch the ground like old hens. Canyon Towhees display these same sociable and appealing features, plus you also run into them in some of the wildest arid to semiarid brushy scrub imaginable, where they can be as shy and secretive as any quail. Here at the cabin the one in the photograph has a special affinity for scratching beneath the spreading, head-high pricklypear cactus just outside the porch door. In Spanish the Canyon Towhee is often known as "Rascador Arroyero," which means something like "gully scratcher."

Of course the scratching is for food, mainly seeds in the winter and insects and other small arthropods in the summer, and earthworms are a delight for it anytime.


The other day I came across the scat shown at http://www.backyardnature.net/n/13/130203__.jpg.

The scat was about as thick as my little finger and so dried out that it had broken. One of the pieces broken off is the white tip at the bottom, right of the longer brown piece. Here's the thinking process I went through to figure out what it was:

First, the size tells us that it was no small creature like a mouse or sparrow.

The white, broken-off end is important because that whiteness is uric acid. It happens that among the higher animals there are two main ways of getting rid of the nitrogenous wastes removed by the kidneys from the bloodstream. Most amphibians and mammals, including humans, pee out water in which the nitrogenous wastes are expelled in the form of urea dissolved in the water. Most birds and reptiles have a more efficient method requiring less water. They convert their nitrogenous wastes into white, pasty uric acid, which is daubed onto poop as it exits the body, and that's why the broken-off tip of our poop is white. Therefore, we know that in the picture we have the scat of either a large reptile or a fairly large bird. In Mexico our Black Iguanas might have produced scat similar to that in the picture, but up here we don't have any reptiles capable of producing such large turds. Therefore, the question becomes, "Which large bird species made this?"

Looking closely at the poop's content we see that there are seeds and parts of seeds, maybe some insect parts, and some dirt that surely was ingested as the bird pecked for seeds and insects on the ground. That disqualifies hawks and other bird predators, for their scat would contain bones and feathers of their prey.

Other large birds in our area include herons and cranes, but their excrement normally is looser and watery. I suppose it could be Pheasant, but I've not run into that species here. At this point you just can't avoid the obvious: It's Wild Turkey scat, which it has every right to be because Wild Turkeys are abundant in this area.

To confirm the diagnosis, pages on the Internet inform us that Wild Turkey scat is cylindrical and blunt-tipped, often gently curving like ours, or J-shaped. And it's composed of the remnants of seeds and insects like ours. Of course the size can vary and the color, shape and texture can differ tremendously from that of our specimen, depending on the foods recently eaten and the health of the bird.

I have read that the male gobbler's droppings usually take the shape of a "J" or sometimes a question mark, while the hen leaves droppings more closely resembling a spiral dropped into a pile. I haven't been able to confirm that, however.


One insight arising from my weekly safaris through drops of water from the little Dry Frio River behind the cabin is that a succession of organisms appears over time. One week a certain species will be abundant, then the next week maybe it'll be rare or not to be seen, while another species not seen before will be most conspicuous. You can see the organism observed for the first time this week at http://www.backyardnature.net/n/13/130203st.jpg.

The critter I'm talking about is the curving, slender, horn-shaped one with its head at the picture's upper right. The two dark "bars" extending diagonally across the image are filaments of Spirogyra alga containing spiraling chloroplasts.

The horn-shaped being is one I've been looking for, one of the most famous of one-celled protozoans. That's because of its common occurrence worldwide in freshwater lakes and streams, its unusual and easy to recognize form, and because -- despite its microscope size -- some species of its kind are among the biggest known unicellular organisms. Some species reach 2mm in length (3/16ths inch), though ours was only about half that size.

This is Stentor, the name being both its genus name and the name used when speaking of it in normal English. Stentors belong to the same phylum as the tulip-shaped, cilia-waving Vorticellas we looked at earlier, and behave somewhat like them. That is, you find them rooted to certain spots such as filaments of alga, extending their bodies here and there, the hairlike cilia on their "heads" sweeping food particles into their "mouths." Like Vorticellas, if a Stentor is disturbed or has been stretched out feeding in one spot for awhile, it suddenly contracts into a ball at its "root" and then slowly begins lengthening again, filtering water with its cilia, looking for food as it grows longer. The Stentors I've seen tend to detach themselves every few minutes and swim about until they find a new foothold.

In our photograph, notice the faint, clear, bubble-like items lined up along the lower part of the curving body like a string of beads. That's the macronucleus, typical of ciliate protozoans. A much smaller micronucleus also is present but I can't say which dark spot in the body that would be. The macronucleus is composed of hundreds of chromosomes, each present in many copies, and controls asexual functions such as metabolism. It undergoes direct division without mitosis. Micronuclei handle the organism's sexual reproduction during conjugation, and evolution, and it does undergo mitosis.

The precise way the ciliates' micro- and macronuclei cooperate is still unknown. It's one of those "mysteries of science," as one expert says.

A close-up of Stentor's "head," looking a little like a Walrus's head, is at http://www.backyardnature.net/n/13/130203su.jpg.

In that picture the Walrus's whiskers are Stentor's food-gathering cilia, technically known as peristomial cilia. The large, round, bubble-like item that could be the Walrus's open mouth is the contractile vacuole, which through the process of osmoregulation keeps the cell from getting waterlogged. The vague dark spot at the base of the Walrus's nose is the mouth, or buccal cavity. I'm unsure what the black item forming the Walrus's eye is, but it could be a food vacuole.

Mostly Stentor feeds on bacteria and other protozoans.


In any other season than now, it's doubtful that I'd have noticed that a stone's throw up a little dry arroyo the road dipped into there was a kind of tree I hadn't yet identified in this area. Any other time of year its dark green leaves would have blended with dark green foilage of all other tree species. However, nowadays all our trees are either dark green -- like the Ashe Junipers and Texas Live Oaks constituting maybe 95% of our forest trees -- or else leafless, or maybe some of the Texas Red Oaks still bear a few dark, rusty red leaves. This arroyo tree -- clearly some kind of oak -- wasn't like any of that, however. Its leathery leaves were brown like old parchment, as you can see on some sprouts arising from the tree's horizontal, fifteen-inch-thick (40cm) trunk that was leaning out over the arroyo, at http://www.backyardnature.net/n/13/130203qu.jpg.

At first I thought the tree was a Post Oak -- we're at the most southwestern point of that species' distribution -- but the leaves weren't really shaped right. Also, Post Oak leaves are hairy underneath and these were hairless, and acorns found beneath the tree didn't look right, as you can see at http://www.backyardnature.net/n/13/130203qv.jpg.

Nor did the leaves and acorns match any of the trees in my tree field guide. Therefore, remembering that the online "Flora of North America" has its oak section finished, I went to the Flora's treatment of all 90 North American oaks and "keyed out" our arroyo tree with its parchment leaves. The Flora's oak-keying-out page is at http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=127839.

No bristles on leaf margins... sinuses between leaf lobes extending less than one-third the distance from the leaf's margin to the midrib... leaf veins not conspicuously parallel but rather somewhat curved and branching... no hairs on the leaves' undersurfaces... acorn cup enclosing 1/3 or less of the nut...

The key lead me directly to the Lacey Oak, QUERCUS LACEYI, which I'd never heard of. Lacey Oaks are a little-known oak species described as occupying canyons and streamsides in limestone hills (like here), and occurring only in a couple of states of arid northeastern Mexico, some isolated spots in two counties in the Big Bend area of extreme western Texas, and the Edwards Plateau of Texas, which is exactly where we are.

So, this is a fine discovery! It's always a pleasure to meet any tree that's new to me, and it's especially good to find one that occurs in such a small area and is known by so few people.


Still looking for spring's first flowers, each day I look in places such as the south-facing side of the cabin to see the cabin's reflected sunlight has induced some early blossoming. I think some yellow Prickly Sow Thistle flowers would be showing up by now if Minnie the Neighbor's Cow hadn't broken through the fence one day and eaten them all, along with a goodly part of the treasured thornless pricklypear cactus beside the back door.

But there was indeed a blossoming wildflower there this week, an herbaceous annual so tiny that most folks wouldn't have noticed it, and certainly they wouldn't see the flowers, which are only about 0.5mm across (1/50th inch). You can see the mat-forming plant with my finger poking in from the left to show the scale at http://www.backyardnature.net/n/13/130203ch.jpg.

In that picture you can barely make out the flowers nestled between opposite leaves on pink stems. A close-up of two blossoms is at http://www.backyardnature.net/n/13/130203ci.jpg.

If you know your common wildflowers and weeds already you recognize that this a spurge, a member of the Euphorbia or Poinsettia Family, and more precisely, a member of the huge genus Euphorbia. Euphorbia blossoms are unique among all flowers and in the above picture you can see what's so special about them.

For, the two items in the picture we've been calling flowers are in fact clusters of flowers arising in structures referred to as cyathia (singular cyathium). Notice that from the cyathium on the left a green, oval item bearing five pale, slender things (they're styles, each bearing a deeply lobed stigma) emerges on a stem. The oval item is the ovary, which will mature into a fruit containing seeds. In other words, the female flower is hanging outside the cuplike cyathium. Inside the cyathium reside three to five male flowers, each consisting of no more than a single pollen-producing stamen. A view of a cyathium under a dissecting scope is shown at http://www.backyardnature.net/n/13/130203cj.jpg.

In that picture the five white things we think of as flower petals are "gland appendages"; cyathium flowers bear no corolla or petals. The glands are the sticky-looking, oblong items at the base of each white appendage. Presumably the glands attract pollinators

So, which spurge is this teeny herb with its teeny, flower-like cyathia? Though maybe 2000 species of Euphorbia are recognized worldwide our species was easier than expected to distinguish from all the others because of its small size, lack of hairs, and its mat-forming, herbaceous nature. Among its English names are Mat Euphorbia, Matted Sandmat and Creeping Spurge. It's EUPHORBIA SERPENS, a native of South America, but now established as an invasive nearly worldwide, including most of North America, except for upper Canada, some of the Atlantic states of the US, and the Pacific Northwest. Its habitat is described as stream bottoms, prairies, clay flats and disturbed sites. The cow-frequented dirt below the cabin's south-facing wall qualifies as a disturbed site.

Some authorities place this species in the closely related genus Chamaesyce, so you might find it listed as Chamaesyce serpens.

Of what use is such a modest little plant? Certainly its seeds are eaten by this or that small bird or rodent, plus it tends to form its mats on disturbed soil where other plants aren't growing, so it retards erosion, and replaces naked dirt with oxygen-producing herbage. And when you see the elegance of its tiny flowers you know that its greater value is that it is just itself, being the very best self it can be.


Here in the southwestern Texas Hill Country where the hills are composed mostly of Cretaceous limestone there are plenty of plants adapted to growing in thin, calcareous soil atop limestone, and from fissures in limestone cliffs. Cliff faces are especially good places for finding interesting, limestone-loving ferns, and within walking distance of the cabin I've found a nice assortment of them. Just last week we profiled the Alabama Lipfern, and not much earlier we had the Floury Cloak Fern, both members of the genus Cheilanthes.

This week, growing from a cliff face along the river another limestone-loving fern species turned up surrounded by several Alabama Lipferns. You can see its unusual, twice-pinnate fronds with their long, slender terminal pinnae, and dark purple, nearly black petioles and rachises at http://www.backyardnature.net/n/13/130203pe.jpg.

This is a species I know well from limestone areas back in Kentucky and Appalachia in general. It's the Purple-stem Cliffbrake, PELLAEA ATROPURPUREA, found on limestone outcrops throughout most of the eastern and south-central US, and all through Mexico into Guatemala.

The "brake" in the name cliffbrake doesn't arise from the fact that cliffbrakes break up rocks in the cliffs they inhabit, but from the use of the word "brake" in English back in the 1300s, when it was used to apply to ferns in general. That word had been introduced into the British Isles by colonizing Vikings, even today the Danish word for fern being bregne.

Fifteen species of cliffbrakes, genus Pellaea, are treated in the online Flora of North America and our Purple-stem one is by far the most widely distributed and best known. In our area we have other endemic and mostly Mexican species I'll be looking for.

Cliffbrakes belong to the same fern family as the lipferns, and as such they also bear their spore-producing, tiny, baglike sporangia inside the fronds' turned-under pinnae margins, as shown in a close-up of some of our Purple-stem Cliffbrake's pinnae at http://www.backyardnature.net/n/13/130203pf.jpg.

Each of the tiny, brown, spherical sporangia peeping from beneath the turned-under margins contain 32 spores, so you can see that fern spores really are microscopic things, and it's amazing how a single spore that germinates into a prothallus that gives rise to a whole fern.

It's reported that traditionally infusions or "teas" of Purple-stem Cliffbrake were used by certain indigenous people in California to "flush the kidneys" and "thin the blood." Dr. John Scudder in his 1870 book Specific Medication and Specific Medicines asserts that an alcohol tincture of the plant "... exerts a marked influence upon the excretory apparatus, controlling diarrhoea, dysentery, night sweats, hemorrhages, etc."


Lately we've been examining lichens commonly on tree branches in this area, but this week I changed my focus to lichens growing on our rocks. Lichens on trees are said to be epiphytic, while those on rocks are saxicolous.

The first lichen to catch my attention was by no means our most commonly encountered saxicolous species, but it's certainly one of the prettiest, at least up close. First take a look at its habitat, on a limestone boulder partly shaded by Ashe Junipers on a slope next to the river, shown at http://www.backyardnature.net/n/13/130203lk.jpg.

In that picture the boulder is blotchy with many kinds of lichens, but the one we're focusing on is the round one with a white fringe and dark center at the top, right of the squarish depression near the rock's center. A close-up of the lichen, a saucer-sized, crustose one, is at http://www.backyardnature.net/n/13/130203li.jpg.

A close-up of the tiny, orange-centered, spore-producing apothecia is at http://www.backyardnature.net/n/13/130203lj.jpg.

Mainly using the field marks of its being a crustose lichen occurring on limestone, of bearing small, orange apothecia, and of occurring in this part of the world, the excellent LichenPortal.org "Dynamic Key" at http://lichenportal.org fairly easily enabled me to "key out" this lichen as CALOPLACA GALACTOPHYLLA, variously known as Firedot Lichen, Jewel Lichen, or just Orange Lichen. There's not much information available for it, but it seems to occur mostly in North America's semiarid central region, the prairie, and farther south into arid northern Mexico.

Hardly anything is stated about its ecology, though that may be because it's so obvious that the lichen just lives on that rock, and it's known that very, very slowly lichens help break down rock into nutrients the whole ecosystem eventually benefits from.

The main "value" of this pretty and patient little being is surely that it exists, adding grace and charm to the lives of any sentient, sense-of-esthetics-endowed, spiritual beings willing to notice it.


Whenever my life is settled enough to have access to large jars, clean water and beans, an important part of my diet consists of bean sprouts that I sprout myself. I find the tastiest of sprouts to be those of alfalfa and mung bean, but here I don't have those beans, so I sprout what I can find. Lately that's meant pinto and white Great Northern beans, the latter being very similar to Navy, or Boston, beans, and all available on the shelves of the local supermarket.

One of my most popular web pages is the one describing how to sprout alfalfa beans at http://www.backyardnature.net/simple/alf-spr.htm. Sprouting larger beans follows the same procedure, except that it may be more foolproof, since air circulates better between the beans so there's less chance of fungus and bacteria contaminating the sprouts. You can see two jars of sprouts I grew this week -- pinto beans up front and Great Northern in the back -- at http://www.backyardnature.net/n/13/130203bn.jpg.

Those are patches of a lady's stockings covering the mouths. Here's how I sprout them:

I pour beans about an inch deep into a jar, run it half full of water and let them soak overnight. Next morning I pour off all the water, secure a stocking patch over the mouth, and turn the jar on its side. Two or three times a day I pour water into the jars, swirl it gently, then pour it out. This keeps fungus and bacteria from building up. By the second day little white roots begin arising from the beans, then day after day the sprouts grow, the rate of growth depending on the temperature. The pinto beans up front in the above picture are maybe four days old. They're turning green because enough sunlight bounces around the kitchen for photosynthesis-enabling chlorophyll to be activated, which is good because that enhances the beans' nutritional value.

In fact, I read that when beans sprout, their stored complex compounds, which are fairly indigestible, break down into simple compounds that enhance the beans' nutritional content by up to 1200%. And the organic compounds produced by sprouted beans are readily assimilated by the body. You can see a handful of sprouted pinto beans just the way I like them at http://www.backyardnature.net/n/13/130203bo.jpg.

Though I like alfalfa sprouts raw, I find larger sprouted beans that have begun turning green to be too tough and bitter to eat raw. One way I prepare them is to sauté them and mix large amounts of them into my cornbread batter, and make a kind of thin-bodied, hard-crusted bean cornbread that bakes quickly in a skillet over a fire.

Sautéed big beans quickly soften and lose their bitterness, and in fact don't have much taste at all. I like to sauté equal amounts of large bean sprouts and shredded cabbage, the end result tasting mildly of sauerkraut. I spritz bowls of this with a sauce made of ¼ vegetable oil, ¾ vinegar poured into a small jar filled with minced fresh onion and garlic with a bit of salt, and boy that's good with hot slabs of cornbread.

I don't notice a gas problem when I eat a lot of these sprouts, so maybe it's true what I read about the sprouting process reducing the beans' oligosaccharide content, which causes the gas problem. Oligosaccharides are a type of carbohydrate that enzymes and bacteria in the stomach can't digest, so it lasts until special bacteria in the large intestine decompose it, forming carbon dioxide, the gas, and water. It's funny that some people worry about eating foods with oligosaccharides because they think it's bad for them, while others make a special effort to eat them, saying that in the intestines oligosaccharides feed "good bacteria," which displace "bad bacteria."

Really you don't know who to believe in these matters and that's why I just eat lots of bean sprouts because I like them, my body seems to react favorably to them, and they taste so good with hot cornbread. You can see one of my recent slabs of bean-sprout-filled cornbread moments before I slapped a big handful of fresh cilantro and spinach leaves onto them and doused the herbage with my special onion and garlic sauce at http://www.backyardnature.net/n/13/130203bp.jpg.



"Ant Beneath a Leaf," from the March 17, 2008 Newsletter, at http://www.backyardnature.net/n/p/080317.htm

"Ants On the Road," from the September 18, 2011 Newsletter, at http://www.backyardnature.net/n/p/110918.htm


Best wishes to all Newsletter readers,


All previous Newsletters are archived at http://www.backyardnature.net/n/.

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