September 2, 2012
A BANDED VERMILION FLYCATCHER
Each day a Vermilion Flycatcher, PYROCEPHALUS RUBINUS, patrols around the cabin, often perching on the fence outside my window. You can see him at http://www.backyardnature.net/n/12/120902vf.jpg.
The picture's gauziness is caused by photographing through the window's screen wire. Notice that at least one leg wears a metal band. There's a birdbander someplace who'd like to know where this fellow is.
I've seen Vermilion Flycatchers all through Mexico's arid zones, here and there in Central America and in much of South America, but I was surprised to see one outside my window this far north. In fact, though during the Northern summer they do extend their range a little farther north into the US, here they are permanent residents. Occupying such an extensive area, the species is fragmenting into subspecies -- at least 13 subspecies being recognized.
Vermilion Flycatchers are real flycatchers, belonging to the Tyrant Flycatcher Family, along with kingbirds, pewees and a host of other typically mousy-colored species, so this bird's scarlet plumage is surprising.
There's a female Vermilion Flycatcher here, too, lacking the male's redness, but I'm not sure they consider themselves a pair. They both love the area's wire fences, where they perch until they spot something in the grass below them, swoop down onto their prey, then normally fly to another fence or to a tree's dead, leafless snag. I don't hear them calling. They seem to know that at this time of year their only job is to eat and stay alive.
RIO GRANDE LEOPARD FROGS
While pulling weeds from flower beds around the cabin I upset a couple of fair-sized frogs, causing them to jump into the open. You can see one a split second before he jumped for cover at http://www.backyardnature.net/n/12/120902fg.jpg.
He's a leopard frog, which you can tell because of the heavy blotching and the pair of conspicuous, raised lines, or "dorsolateral ridges," running down the back. However, several leopard frog species are recognized, and there's much variation within some of the species, so here was my first amphibian challenge since arriving here.
I guessed that they were Southern Leopard Frogs like back in Mississippi. However, distribution maps for that species show that it doesn't occur this far west. The "List of Amphibians of Texas" at http://en.wikipedia.org/wiki/List_of_amphibians_of_Texas lists eight species of "true frogs" -- members of the genus Rana -- for Texas, and when I refer to the distribution maps for those eight species, only one is found this far southwest.
And that's the Rio Grande Leopard Frog, RANA BERLANDIERI, said to be distributed from south-central and western Texas south through eastern Mexico into Nicaragua, with an island population in southwestern Arizona and a tiny part of adjacent California. I say "said to be distributed" because they occur in such different habitats that it's hard to believe they're all the same species, and the experts admit that the tropical part of the population is poorly studied. I read that at the reservoir at the rainforest ruin of Tikal in northern Guatemala frogs going by this name are very common, and Tikal's environment is a far cry from what we have here.
The Dry Frio River runs maybe 200 yards (200m) behind the cabin, so that explains what a leopard frog is doing in this arid area. I read that their calls resemble a fast-paced chuckle, like an excited duck quacking, so there's something to look forward to on my first rainy night here. Rio Grande Leopard Frogs are described as fairly common throughout their distribution area.
TEXAS SPINY LIZARD
An eight-inch-long (20cm) lizard climbed up a Live Oak at the corner of a picnic shelter in the community park and he was easy-going enough to permit the picture shown at http://www.backyardnature.net/n/12/120902lz.jpg.
He is similar to the common fence lizards occurring in much of North America, but for one thing: Notice how large and seemingly loose-fitting the scales are. Other fence-lizard type lizards bear smaller, closer-fitting scales.
With those large scales, its color pattern, habitat and presence here in southwestern Texas, this must be the Texas Spiny Lizard, SCELOPORUS OLIVACEUS, found only in Texas, a bit of Oklahoma, and northeastern Mexico. I read that they're often found climbing not only trees but also fences and telephone poles in the suburbs. They eat a variety of invertebrates.
SCORPION BENEATH A FENCEPOST
Around here if something lies on the ground and you need to pick it up, you need to very gingerly flip or roll the object over to see who is beneath it before you poke your fingers there. A fairly common occurrence beneath such objects is what's shown at http://www.backyardnature.net/n/12/120902sc.jpg.
That's the Striped Bark Scorpion, CENTRUROIDES VITTATUS, described as the most common scorpion species in Texas and the most frequently encountered in the US, where it's found in south-central states, as well as much of arid northern Mexico. Our individual was about two inches long (55mm) and kept his tail flush with the fencepost he was clinging to. Notice the pair of eyes atop the head area. You can see what it'd look like if you were a bug being approached by this fellow at http://www.backyardnature.net/n/12/120902sd.jpg.
Besides the two eyes atop the head, which are called median eyes, scorpions usually have two to five pairs of eyes along the front corners of the head. In our picture you can see six more eyes, three on the outer rims of both of the squared, forward projections of the dark head-plate. Those six eyes are called lateral eyes. Despite possessing so many eyes, scorpions don't see well, mostly relying on their sense of touch. They do have a well-developed sense of hearing, though.
The two toothlike items with hairs and black items at their bottoms are chelicerae, which are basically jaws used to grab and crush prey. You can see the stinger, or "aculeus," at http://www.backyardnature.net/n/12/120902se.jpg.
Striped Bark Scorpions are nocturnal and eat small invertebrates -- insects, spiders, earthworms and the like. They are an adaptable species, which accounts for their large distribution area and commonness.
TEXAS LIVE OAKS
Our part of southwestern Texas is a transition zone between mostly oak-rich forests and irrigated farmland to the east, mostly pastured grasslands to the north, and Mesquite scrub, grasslands and desert to the west and south. In my local area, in the valley of the Dry Frio River, the forest is much lower and scrubbier, with much less species diversity, than the Mississippi forests I've just left. This is a very hot, dry environment, so organisms surviving here must have special adaptations.
Our native forest is dominated by just two species -- Texas Live Oaks and Ashe Junipers. Other woody species are present but, at least in my local area, those two species exercise a profound dominance.
My 1968 Trees of North America shows Live Oaks, Quercus virginiana, inhabiting the US Deep South along the Coastal Plain from about Virginia all the way into Texas, even as far west into the arid lands as here, and even into Mexico. I've never understood how the Deep South's Live Oaks, accustomed to high humidity and considerable rain, could survive in arid places like Uvalde County. Now that I'm here, I'm understanding.
Since my tree book was published in 1968 the general consensus seems to have become that we're dealing with two different species. The Live Oak back in Mississippi, Quercus virginiana, extends no farther west than eastern Texas. Here we have a different but very similar species, the Texas Live Oak, QUERCUS FUSIFORMIS, which occupies central and southern Texas, plus southwestern Oklahoma and a bit of northern Mexico. The Flora of North America admits that the two live oak species often intergrade, and individual trees can be hard to distinguish.
So, though I'd find it hard to confirm it, the Flora of North America says that the leathery-leafed, compact tree about 25 feet tall (8m) outside my back door is a Texas Live Oak. You can see its silvery-bottomed leaves and long-stemmed, pointy-tipped acorns at http://www.backyardnature.net/n/12/120902ok.jpg.
Its dark, deeply fissured bark is shown at http://www.backyardnature.net/n/12/120902ol.jpg.
The species forms pretty, cow-friendly "parks" when the junipers are cleared from around them, as shown at http://www.backyardnature.net/n/12/120902om.jpg.
You can compare features shown there with those of a classic Live Oak back in Mississippi at http://www.backyardnature.net/n/w/live-oak.htm.
ASHE JUNIPERS & THEIR CONTROVERSY
Before I arrived in Uvalde County I knew that Ashe Junipers, JUNIPERUS ASHEI, would be common here, for I'd studied closely the big, detailed "Vegetation/ Cover Types of Texas" map in the University of Texas's wonderful Perry-Castañeda Library Map Collection, free for everyone to see at http://www.lib.utexas.edu/geo/pics/vegetationcover2a.jpg.
That map clearly shows that here in northern Uvalde County (the second rectangular county west of San Antonio) there are two main vegetation types. The blue one marked 26a is "Live Oak - Ashe Juniper Parks" while the green one marked as 27 is "Live Oak - Ashe Juniper Woods." The difference between the two zones is that trees in the "parks" are wider spaced than in the "woods." Live Oaks and Ashe Junipers, then, are the dominant natural trees here. Ashe Junipers are endemic to Texas, northern Mexico, and spottily here and there in extreme southern Missouri, Arkansas and Oklahoma. They are a unique and little known species, except in our area, where they are abundant.
Ashe Junipers form a pretty, parklike setting right behind the cabin I'm staying in. You can see how they produce several trunks with branches bearing dark green clumps of scalelike foliage, like the East's Redcedars and the North's Common Junipers (both members of the genus Juniperus) at http://www.backyardnature.net/n/12/120902jo.jpg.
The trunks are particularly "shaggy," as shown at http://www.backyardnature.net/n/12/120902js.jpg.
A close-up of leaves and pale blue seed cones is at http://www.backyardnature.net/n/12/120902jp.jpg.
The cones' paleness is caused by a silvery "bloom." A thumb can rub off the bloom very easily. Technically such a bloom, which also covers certain plums and other fruits, is referred to as glaucescence. This cone glaucescence helps distinguish Ashe Junipers from certain other juniper species farther north at higher elevations. A close-up showing cones with some of their bloom rubbed off is at http://www.backyardnature.net/n/12/120902jq.jpg.
A close-up showing scale-like leaves, each one with a noticeable bump at its base, is at http://www.backyardnature.net/n/12/120902jr.jpg.
I'm focusing on details here because in this area a certain controversy rages with regard to the Ashe Juniper and I can imagine individuals invested in one side or the other claiming that I must be talking about some other species. Anyone who sees our pictures and knows what an Ashe Juniper looks like will understand that here we're dealing with Ashe Junipers.
In front of the house where I live the landowner on one side of the hill has removed all Ashe Junipers, as you can see at http://www.backyardnature.net/n/12/120902jt.jpg.
In fact, most of the landowners in this community are "eradicating" the Ashe Junipers on their land. Even people not in favor of the idea are paying hundreds and even thousands of dollars to get rid of their Ashe Junipers because they want to be "good neighbors," and the community consensus is that the Ashe Junipers have to go. Not long ago the state of Texas paid landowners to kill Ashe Junipers. When I asked why, a person doing his share of Ashe Juniper killing gave two reasons: 1) Ashe Junipers rob water from other more desirable species, and 2) Ashe Junipers are invasive, and therefore should be removed like any weed species.
Our vegetation map shows that they're not invasive, and you can find links to scientific studies showing that in the long term the grassy ranchland resulting when Ashe Junipers are removed takes more water than natural Ashe Juniper forests at http://www.treecoalition.org/ashe.htm.
Last week we looked at yellowing persimmons in Mississippi which, unfortunate for me, don't occur this far west. However, there's another persimmon species -- one found only in the southern half of Texas and northern Mexico -- on the slope down to the river behind the cabin, as you can see at http://www.backyardnature.net/n/12/120902ps.jpg.
This persimmon tree is about ten feet tall (3m), is compact with gnarly branches, and its small, deciduous leaves are leathery and brittle. You can see that its persimmons, unlike last week's Common Persimmon of eastern North America, is black. In fact, sometimes this species is called the Black Persimmon, but mostly it's called the Texas Persimmon. It's DIOSPYROS TEXANA. In Mexico it's called Chapote or Chapote Prieto.
Last week we made the point that something unusual about persimmon fruits is the very large, leathery calyx that remains attached until the fruit is overly mature. You can see that Texas Persimmon fruits also have big calyxes. Look at the calyx on the persimmon from which I've taken a bite at http://www.backyardnature.net/n/12/120902pt.jpg.
Texas Persimmon fruits are much juicier and have a less custard-like texture than the East's Common Persimmons, and the ones I'm eating aren't nearly as good. They're a tiny bit bitter, but tolerable if you're hungry. I read that they make a decent jelly but a local native said outright that he didn't like them. Birds, foxes, coyotes and raccoons are reported to eat them.
A FENCE-LOVING CLEMATIS
This is ranch country so, among other things, that means that lots of fences crisscross the landscape. And on these fences very often you see what's shown at http://www.backyardnature.net/n/12/120902cl.jpg.
Any plant producing so much fuzz is bound to be called Old Man's Beard or Goat's Beard -- and these are among this vine's most common names. Other more definitive names are Texas Virgin's Bower and Drummond's Clematis, the latter name being the most apt, since the fence sun-catcher is indeed a clematis, CLEMATIS DRUMMONDII, native to the US arid Southwest from southern California to southern Texas, and much of northern Mexico. A close-up of one of the vine's fuzz-puffs is shown at http://www.backyardnature.net/n/12/120902cn.jpg.
There you can see that the fuzz consists of abundant, white hairs on long, slender, curving necks, or "beaks," atop numerous achene-type fruits, achenes being one-seeded, dry fruits that don't split open at maturity.
The fuzzy fruiting heads are typical of the clematises, but the Drummond's Clematis's leaves are exceptionally slender, rangy things that somehow seem appropriate for this arid, sun-baked environment, as shown at http://www.backyardnature.net/n/12/120902cm.jpg.
The vine produces no tendrils, but the leaves' wiry petioles and rachises serve as tendrils, half-heartedly but effectively hooking themselves onto bush branches and fence wires.
The vine's flowers are nearly as understated and no-nonsense as the leaves, as you can see at http://www.backyardnature.net/n/12/120902co.jpg.
About 32 wild clematises are listed for North America (±300 worldwide), and some species produce flowers with both male and female parts, while other species produce unisexual flowers. Drummond's Clematis bears unisexual ones. The flower in the picture is female. Male and female flowers occur on different plants. Our flower's stamens, looking like pale little matchsticks arising at the pistil's base, are rudimentary and sterile. The pineapple-like object in the flower's center are the female stigmas and styles. Notice that the flower bears no petals, or corolla, for its large sepals serve the corolla's function of attracting pollinators.
Traditionally teas have been brewed from Drummond's Clematises to ease headaches and migraine.
FEATURED ESSAYS FROM THE PAST:
"Disorganized Zone of Disturbance," from the June 26, 2011 Newsletter, at http://www.backyardnature.net/n/p/110626.htm
"Struggling Toward a More Articulate Croak," from the May 16, 2004 Newsletter, at http://www.backyardnature.net/n/p/040516.htm
Best wishes to all Newsletter readers,
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