April 27, 2014
SNAILS STUCK TO WEED STEMS
At Cooks Slough Sanctuary and Nature Park on Uvalde's south side, in a low spot where water pools after rains, a couple of last fall's dead, weathered sunflower stems conspicuously bore white snail shells stuck to them about a yard (1m) above the ground. You can see one, with my finger for scale showing that the shells were about ¾ inch long (2cm), at http://www.backyardnature.net/n/14/140427sn.jpg.
The shells were so white and eroded looking, that they seemed to belong to long dead snails, but of course the sunflower stems' age and the fact that the shells were glued to them suggested that this was the shells' normal appearance. Still, to convince myself that live snails still were housed inside the shells, I looked at the shells from behind and could see pale snail tissue, and what must have been black curds of dried snail poop, as shown at http://www.backyardnature.net/n/14/140427so.jpg.
A closer look at a second snail's shell, showing subtly different patterning, is at http://www.backyardnature.net/n/14/140427sp.jpg.
Identification of the snails was helped by the same website that back in our days on the Yucatan's beaches was the place to go to learn the names of seashells. You can see that site's page for our snail, along with a distribution map showing where it's found in the US -- with us about in the center of it -- and the snail's white flesh, at http://www.jaxshells.org/deal.htm.
That page identifies our snails as the Whitewashed Rabdotus, RABDOTUS DEALBATUS, present not only in the US, mainly in the south-central states, but also in most of lowland Mexico.
One of the most interesting historical accounts I've read is "La Relación," by the Spanish conquistador Álvaro Nuñez Cabeza de Vaca, about his wanderings in what later became the US, including our area, first published in 1542. He chronicles the coastal Texas Mariame Indians collecting and eating snails during their wanderings collecting prickly pear fruits, or tunas, for food. Most likely, the main or only snail collected by the Mariame was our Whitewashed Rabdotus.
Evidence supporting that theory has been excavated at the the J. B. White Archaeological Site on the Little River in central Texas, where thousands of Whatewashed Rabdotus shells turned up in long-buried strata of soil on which ancient indigenous Americans once camped. Because all the shells at that site were those of adult snails, which would have been collected for food while ignoring the smaller, younger ones, it's assumed that the shells were left there after their contents had been eaten.
You might enjoy the webpage describing daily life of the early Americans who lived at the J.B. White Site. The page is at http://www.texasbeyondhistory.net/jbwhite/dailylife.html.
That page suggests that the snails were probably cooked in pits in the ground using the stone-boiling method, a process illustrated on that page. You can also see many Whitewashed Rabdotus snail shells in the site's soil.
Ecologically, Whitewashed Rabdotuses are described as "calciphile," meaning that they prosper in soil with a high calcium content, such as that derived from limestone. In Texas the species often is encountered inside concrete culverts.
CONFRONTATION WITH A COWBIRD
All winter my bird feeder was visited almost exclusively by Chipping Sparrows and Black-crested Titmice, with a Cardinal couple making occasional quick visits. About a month ago House Finches appeared, just a few at first but now they're the main species at the feeder. The sparrows and titmice come daily, but in much fewer numbers. This week, Brown-headed Cowbirds have appeared for the first time. Our page for that nest-parasitizing species, with several pictures, is at http://www.backyardnature.net/n/b/cowbird.htm.
When a cowbird arrives at the feeder, smaller sparrows and titmice normally fly away, but sometimes a finch tries to hold his ground. You can see a male House Finch gamely trying to face down his opponent -- for about a second before losing his footing, fluttering flounderingly and flying away -- as the much larger male cowbird imperiously adds to his height by lifting his head as if about to thrust downward, at http://www.backyardnature.net/n/14/140427cb.jpg.
It's hard to say whether the bird feeder's changing visitor profile is due mostly to seasonal behavioral shifts among the species, or whether it's simply a matter that with time the more aggressive species are gradually taking over. The picture suggests that at least some of the later is happening.
GRAY BIRD GRASSHOPPER
Clinging to the wall of my neighbor Phred's garage one morning this week was the largest grasshopper I've seen in this area, about 2¾ inches long (7cm), shown at http://www.backyardnature.net/n/14/140427gh.jpg.
A picture better showing the distinctive white patches on the face and the front part of the thorax, the pronotum, and the handsome chevron pattern on the hind leg's femur, is shown at http://www.backyardnature.net/n/14/140427gi.jpg.
And just for fun, a picture taken by Phred of me taking the above pictures is at http://www.backyardnature.net/n/14/140427gj.jpg.
By looking at grasshopper pictures at BugGuide.Net, volunteer identifier Bea in Ontario figured out that this might be the Gray Bird Grasshopper, or Vagrant Grasshopper, SCHISTOCERCA NITENS. My further checking on the species found that the species is commonly seen in this area and is to be expected, so that's what I'm calling it. Gray Bird Grasshoppers are mostly a tropical species, occurring from northern South America up through Central America and Mexico, and entering the US from California to Texas and Oklahoma.
Gray Bird Grasshoppers are solitary and non-migratory, but under certain conditions they form swarms that fly long distances and cause damage to crops and native plants. They've been introduced into Hawaii, where in 2002 and 2004 outbreaks on the island of Nihoa led to the defoliation of almost all the vegetation, including endangered plant species.
The name "bird grasshopper" is applied to members of the genus Schistocerca, apparently because of their large size, approaching that of small birds.
ETHMIA MOTHS ON WHITE PAINTED WALLS
These days I'm painting buildings. After scraping off old paint and caulking holes and seams, first a white primer is applied, then the final color. When the building is all white with the primer, that's when the building becomes a magnet for a certain little moth, the one shown on a freshly primed wall, at http://www.backyardnature.net/n/14/140427et.jpg.
Its a small moth, only about half an inch long (12mm), but with that distinct pattern of black dots on the back, volunteer identifier Bea in Ontario quickly figured out that it was an Ethmia Moth, ETHMIA SEMILUGENS, a species restricted to the arid parts of the southwestern US and the northern half of Mexico.
Not much information is available on the Internet concerning this species, other than that in California its caterpillars feed on the leaves of Phacelia wildflowers. We have two Phacelia species in our area, so it all works out.
And maybe we can add some new information here. For, as I browsed other peoples' pictures of Ethmia semilugens on the Internet, it was striking how often the moths photographed appeared on white surfaces, as in our picture. Maybe this mouth seeks out white surfaces as part of its camouflage strategy, though on a plain white surface the moth's body bears enough black spots to make it very visible. Howeve, except on snow and white sand, expanses of white in Nature generally are broken with dark specks, blotches and cracks, and there this moth's camouflage might serve very well.
JARVIS'S VULTURE NOTES
Two weekends ago my friend Jarvis from graduate school days visited, driving round-trip between Asheville, NC and here. Jarvis is a retired college professor who specializes in ecology and birds, and in recent years has been paying special attention to vultures. Upon his return to Asheville, the wrote:
"I saw a very great number of vultures in southern and central Texas compared with other regions - probably more than 5 times as many per hour compared with states other than Texas. Also, I saw more Black Vultures in Texas than I could easily count. I saw no Black Vultures in Louisiana or Mississippi and only 3 in Alabama (on the way out and back). I suspect there is a close correlation between the population of cows and the population of vultures. Maybe the deer population is a factor as well."
Lloyd Kiff's paper published in 2000, "The Current Status of North American Vultures," points out that from the 1950s to the early 1970s, North American vulture populations declined because of the use of DDT but now the populations are stable and in fact Black and Turkey Vultures are extending their ranges northward. That paper is available for free in PDF format at http://www.globalraptors.org/grin/researchers/uploads/118/status_of_vultures.pdf.
Kiff supposes that behind this northward range extension lie increases in the deer population, increased availability of road-killed animals, reduced pesticide use, reduced human persecution, the increased number of landfills, and a general warming trend.
MEXICAN PRICKLY POPPY
In this area we've already looked at white-flowered and rose-flowered prickly poppy species. At the edge of a concrete walk at my neighbor Phred's, a yellow-flowered one is blossoming, shown at http://www.backyardnature.net/n/14/140427ag.jpg.
A close-up of a flower with a spiny flower bud below it and to the left is shown at http://www.backyardnature.net/n/14/140427ah.jpg.
Prickly poppy petals don't last long and are shed easily when the flower is handled. A view inside a blossom whose petals and stamens have fallen off one side appears at http://www.backyardnature.net/n/14/140427ai.jpg.
The spiny, egg-shaped item in the blossom's center is the ovary and atop it is the purple stigma, its lobes fuzzy to catch pollen. You can see that this ovary means to bear some large, stiff spines when it matures into a capsular fruit.
In North America fifteen prickly poppy species -- fifteen members of the genus Argemone -- occur in the wild. Most of those produce white or pale lavender blossoms, with only three species bearing yellow, golden or bronze flowers. Two of those yellow-flowered taxa might be found in our area. Blossoms of one of those species, Argemone aenea, have 150 or more stamens with red or purplish filaments, while flowers of the other one, Argemone mexicana, bear only 20-75 stamens with yellow filaments. A quick glimpse at our last picture convinces us that here we have ARGEMONE MEXICANA, the Mexican Prickly Poppy.
In southwestern Texas, Mexican Prickly Poppies are regarded as invasive weeds, as they are in many of the world's warmer countries and regions. It's unclear where they are native to, though many suppose that they originated from Mexico and Central America. In much of Africa and Asia Mexican Prickly Poppy is regarded as a serious agricultural weed, especially because livestock won't eat it, and the plants produce chemicals that retard seed germination and seedling growth of many plants. Such chemical inhibition of other plants' germination and growth is referred to as allelopathy. Harmful allelopathic effects of Mexican Prickly Poppies on germination and seedling vigor of wheat, mustard, sorghum, tomato, cucumber and many other useful plants have been documented
Despite all that, most pages on the Internet concerning Mexican Prickly Poppy deal with the plant's medicinal and psychotrophic uses. Some people smoke the leaves to feel relaxed or have highs of various kinds, the effects being similar to those of opium, the Opium Poppy being in the same family as prickly poppies. Mexico's Aztecs used this species extensively in rituals. In today's drug culture, some regard Mexican Prickly Poppy as a "teacher plant," a plant whose use engenders deep insight. In the Caribbean, plasters made from the plant are used to remove warts. In fact, the plant finds all kinds of uses in many cultures throughout the world.
SIX-WEEKS FESCUE IN A BALD POTHOLE
A couple of weeks ago we found some interesting, not-very-common plants in a special habitat consisting of highly calcareous soil collected in a tub-size depression in the hard, bare Edwards Limestone capping our hill here. A picture of that extreme habitat is still at http://www.backyardnature.net/n/14/140413vw.jpg.
Growing among the Split-leaf Gilia and Hilly Sandwort, which made that little natural pothole so special, grew a tiny grass. It bore immature flowers then, but now two weeks later already the grass plants are dead and dried-out, and their heads bear grains ready for dispersal. I figured that if this lilliputian grass thrived in such a unique habitat, it might be something special, and I've been looking forward to identifying it. Several of the brown, dried-up grasses are shown in their thin, crusty, rocky, extremely dry soil at http://www.backyardnature.net/n/14/140427vu.jpg.
You can see how small the plants are relative to my fingers at http://www.backyardnature.net/n/14/140427vv.jpg.
In structure, this plant is very similar to several common grasses, such as the fescues and brome grasses, but its tiny size is remarkable. A close-up of a spikelet on a short stem, or pedicel, consisting of ten or so florets with sharply long-pointed lemmas is shown at http://www.backyardnature.net/n/14/140427vw.jpg.
Three of a flowering head's broken-apart florets are seen beneath the dissecting scope at http://www.backyardnature.net/n/14/140427vx.jpg.
Along with the above-mentioned features, to identify this species it's important to notice that the sharp-pointed lemmas display no conspicuous veins on their rounded backs. Also, each spikelet's two lowermost scales, the glumes, are not quite as long as the lemmas.
Back when I was learning my plants, these features would have led me right to the fescue grasses, genus Festuca. However, since those days taxonomists have shifted several fescue species to the genus Vulpia, and this is one of those. It's a widely distributed grass, so it goes by many names, including Sixweeks Fescue, Sixweeks Grass, Eight-flowered Fescue and Pullout Grass. It's VULPIA OCTOFLORA, native from southern Canada through all the lower 48 states and the arid northern half of Mexico. Presumably the "six weeks" part of its name is based on the grass' supposed lifespan.
Sixweeks Fescue is not at all restricted to such habitats as our hilltop pothole. It's described as inhabiting not only hilltop "balds" like we have here but also ledges, ridges, meadows, fields, and many kinds of weedy, disturbed sites.
Beside the gravel road leading into Cooks Slough Refuge on Uvalde's south side a ferny-leafed little herb with its stems twisted as if deformed by herbicides caught my attention. For one thing, each small, bilaterally symmetrical flower bore a nectar-bearing "spur" that projected behind it, making the blossom very similar to what wildflower lovers know as Corydalis. However, the Corydalis species I know bear yellow flowers, while these were white, with a dark purple spot. You can see the twisted plant at http://www.backyardnature.net/n/14/140427fu.jpg.
A close-up of its unusual flowers is at http://www.backyardnature.net/n/14/140427fv.jpg.
Unable to find any Corydalis species looking like this, in the online Flora of North America I went to the Fumaria Family page, for that's the family the Flora says Corydalis belongs to, and keyed out the plant. The genus I came up with was the fumatory genus Fumaria, native to the old world, with no species native to the Americas.
Our introduced little fumatory seems to be FUMARIA DENSIFLORA, sometimes called the Dense-flowered Fumaria, and in the US so far it seems to have invaded only a few counties in Texas. You can see its distribution in the US at http://bonap.net/MapGallery/County/Fumaria%20densiflora.png.
Dense-flowered Fumaria is native to the Mediterranean Region, including western Asia, so it must find Texas's dry heat to its liking.
Though the Flora of North America places fumatories in their own family, the Fumatory Family, the Fumariaceae, some experts assign them to the Poppy Family, the Papaveraceae, and that reminds us that in the Old World fumatory species often were regarded as medicinal plants. Mrs. M. Grieve, in her venerable A Modern Herbal, is in her usual confident and somewhat indecipherable form when she says of fumatories in general that they provide... "A weak tonic, slightly diaphoretic, diuretic, and aperient; valuable in all visceral obstructions, particularly those of the liver, in scorbutic affections, and in troublesome eruptive diseases, even those of the leprous order."
FOSSOMBRONIA LIVERWORT UPDATE
This January we looked at a rare and little-documented liverwort discovered on a boulder in the Dry Frio River. That report is at http://www.backyardnature.net/n/x/fossombr.htm.
I've been watching that small population, and in the meantime have discovered others also on boulders in the Dry Frio, all covered with dried, limy muck. The liverworts' main leaves appear to have died back but now bud-like green "sprouts" are appearing. Also, the remarkable spherical spore capsules atop their white stems have for the most part disintegrated.
You can see their current condition at http://www.backyardnature.net/n/14/140427lv.jpg.
THE DRY FRIO IN SPRING
Early this January a certain stretch of the Dry Frio about two miles north of Juniper House in Real County was pictured here so you could see what the landscape looked like in mid winter. That picture is still online at http://www.backyardnature.net/n/14/140105fr.jpg.
Now we can see how the very same scene has changed with the coming of spring. Our spring picture is at http://www.backyardnature.net/n/14/140427fr.jpg.
The pale, green trees along the river are American Sycamores with their leaves expanding. The dark green trees mantling the hills in the background are Ashe Junipers, while the scattered, pale-green trees, especially on the lower slopes -- they're rusty-colored in the January picture -- are Texas Red Oaks. Many trees are neither dark green nor pale green, but rather grayish green, especially on the higher slopes; it's a bit hard to pick them out, but there's a lot of them. They are Texas Live Oaks.
Notice that the water is considerably lower in this picture than it was during early January. This is unusual because right now we are approaching the peak of our spring rainy season. I recall that this time last year the water was much higher, probably completely submerging the large, flat-faced rock at the center-right. Most of the Dry Frio in our area consists of a dry river bed, with only intermittent, slowly drying-up pools like this one.
A GOOD USE FOR OLD PICKLE JUICE
Like many people who buy jars of pickles at the grocery, my neighbor Phred feels bad about throwing away the juice once the pickles are gone. The juice, after all, contains lots of good vinegar and such noble condiments as garlic, cloves, tumeric, mustard seeds, and more. Phred gives me his pickle juice, which I spritz onto this and that for flavor, or maybe add a bit of oil to it and marinate sliced garlic from the garden in it for a really garlicky dressing. And lately I've been trying something else:
I keep three or four jars of various kinds of sprouting beans going all the time, at different stages of sprouting, so that I never run out. My page showing how sprouting is done is at http://www.backyardnature.net/simple/alf-spr.htm.
Sometimes I end up with more sprouts than I can eat, so I stuff the surplus into one of Phred's jars of pickle juice, sweet pickle juice being preferred. The sprouts marinate and the longer they soak the better they taste in a sandwich, added to an omelet, or just eaten from the jar. A jar of lentil sprouts marinating in sweet pickle juice is shown at http://www.backyardnature.net/n/14/140427pj.jpg.
FEATURED ESSAYS FROM THE PAST:
"Parque Eulogio Rosado" from the April 18, 2010 Newsletter, at http://www.backyardnature.net/n/p/100418.htm
"A Parrot Looking at Me" from the December 13, 2009 Newsletter, at http://www.backyardnature.net/n/p/091213.htm
Best wishes to all Newsletter readers,
All previous Newsletters are archived at http://www.backyardnature.net/n/.