Photo Essay
Vegetated Sanddunes
Much of the sanddune habitat is covered with plants. When a person sees shinoak and sandsage in the landscape the sanddune habitat is present, even if not one dune is visible. The two species will grow on what appears to be flat ground, but somewhere nearby will be small hills that were once dunes, and somewhere will be "blowouts" that remain vegetation-free for years.
Some ranchers have done their best to kill the shinoak so more grass can grow, and have had success, although some shinoak does eventually reappear. Because sandy soil has great ability to retain moisture, the sanddune habitat can become excellent grassland during wetter years.
The 15 members of the 2008 class of the Llano Estacado chapter of the Texas Master Naturalists spent three hours in vegetated sanddunes on a Midland County ranch. It is amazing what so many eyes can see in a landscape that seems monotonous and empty of life at first glance! Photographs were taken by Nina McCart, Leslie Harman, Taffy Armstrong, J.D. Drissell, Mark and Debbie Pelham, Sharon Long, Chris Cherry, R..L. Orth, Sean Patty, and Burr Williams.
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Shinoak less than knee-tall covered hundreds of acres. Some patches of grass were interspersed among the diminutive "trees." When the class first arrived, not a bird was in sight. The only sign of animal life were tracks on open patches of sand.
A band of mesquite cut across the landscape in an area slightly lower than the surrounding shinoak covered land. When the class investigated that strip of mesquite, it appeared that the sand was more compacted.
On April 26th, not all of the shinoak was fully leafed out. Beyond the class is an area where the shinoak appears reddish. More than likely, all of the group of reddish shinoaks were one clone, connected by the extensive rhizomatous root system. There, the leaves were just unfurling. The color comes from the blooms of the shinoak.
Here and there, small blowouts remained free of vegetation. The blowouts were usually lower than the surrounding vegetation.
The sandsage was no taller than the shinoak. On this particular ranch, the sandsage was patchy and not evenly distributed across the land. When found, ten to thirty plants would be found relatively close together, and then a hundred yards would be passed before more was found.
In a few places the shinoak grew 10-15 feet tall. The taller plants were not leafed out yet, either.
Dead leaves of the shinoak were everywhere, along with acorns hollowed out.
The bloom of the shinoak is wind-pollinated, but none of the class suffered allergies despite the billions of the colorful little catkins.
Several different types of galls were found. Almost all had an exit hole where the insect had exited. Whether the insects are wasps, flies, or something else is unknown. The Sibley staff has not yet found a field guide to the gall insects of shinoak.
When a person begins to look closely, the beauty of the vegetation becomes more apparent - the sinuous curves of the shinoak leaf, and the silvery pubescence of the sandsage becomes part of the experience of the landscape.
As the breeze blew, the new growth on the sandsage danced. The landscape "sparkled with spring!"
Sandsage leaves are covered with tiny short hairs. This is an adaptation to conserve moisture. When the wind blows across the leaf, the stomata on the underside of the leaf are protected, so the moisture within the plant is not pulled away. The silvery color of the hairs reflect the sunlight, keeping the leaf cooler.
Some shinoak had no leaves at all, not yet. A paper wasp nest from a previous year and two empty acorn cap were more visible as a result. The leaf buds were just beginning to "break" and the leaves to unfurl.
A kangaroo rat had recently cleaned out its den, removing all of the empty shells of the acorns it had stored for food during the colder nights of the winter.
The shinoak pasture was home to many scaled (blue) quail. Two little piles of quail droppings indicated a pair's favorite night-time roost. Their calls were plentiful earlier in the morning, but as the temperature reached the 80s the calls ceased. Nesting might have been delayed in 2008 from the lack of rain, although the birds were paired up.
Another form of gall was found. With more observation, a naturalist might be able to determine if the location of different galls have any pattern. Is one type found high in the bush, or up on the higher hillocks of sand? Are more found on one clone that another shinoak clone? Can that be related to the timing of the emergence of the leaves? Can it be related to the production of acorns - do the shinoaks with more galls have less acorns?
Game trails snaked through the shinoak, crisscrossing and meandering around. A naturalist might map the game trails and then learn why various animals use these paths over and over. Do they lead to cover? Or do they lead to a shinoak clone with especially fine-tasting acorns? Later photographs will indicate which animals made the trails - but for now, make a guess!
Mexican spotted ground squirrels make holes that go straight down into the soil. No empty acorns were found near their holes - does that mean they do not utilize acorns?
Wolf spider holes were evident among the shinoaks, but this wolf spider was out hunting, clambering over the shinoak leaves from the previous year.
When the photographer spotted this form, he believed he had found an old deer antler. When he picked it up however, he found that it was the remains of a large species of desert puffball mushroom. At least three sizes of stalked puffballs were found.
Several southern prairie lizards were found, but now marbled whiptails, a species that prefers the habitat. Southern prairie lizards are found in several West Texas habitats. Most live only for a year. When temperatures are cool, their skins are dark (to absorb the heat of the sun), but as the day warms up they fade in color to a paler gray.
When the class wandered into the patch of mesquite, bright orange lichen adorned the trunks of some of the 10- 15 foot tall "trees." The new growth of a balsam apple vine had begun climbing the trunk. Under the ground, the balsam apple grows from a huge bulbous root the size of a basketball. Look closer, at the trunk - do you see the dark spots clustered together? The photographer did not notice them, but it was a group of insects. Are they beetles, or bugs? Why were they remaining together? Was it a mating "lek?"
A pair of ladybird beetles (ladybugs) were mating on a mesquite leaf.
No aphids were noticed on the mesquite by the class, but some found tiny thrips on some of the blossoms. Do ladybugs eat thrips?
Why does the orange foliose lichen have little projections on the edge of the "cups" of the plant? Why were some of the cups more open than others? They reminded one class member of a venus fly-trap leaf - but surely a lichen does not get some of its nutrients from trapped insects!
Packrat nests were mostly found under mesquites and lotebushes, although a few were found in shinoak clumps. Is there a reason for that preference? Mesquites and lotebushes have thorns, but shinoaks don't, so is it strictly for protection from coyotes and badgers that like to dig out the stored food of the packrat (and the packrat, if they are lucky?)
One mesquite had an old badger den (with the usual three entry holes.) A packrat had also built a nest under the mesquite. Who built their home first?
Mesquite is also wind-pollinated. Not all the blooms open at once. Each catkin has hundreds of individual blooms.
When a mesquite bloom is fertilized, does it turn a darker color? Will these individual blooms turn into beans? Notice than many blooms had fallen off, leaving short stubby pedicels.
The mesquite had been present in pasture for many years. This stump was still firmly attached to the ground. Each arm of the stump probably once had a trunk. The whole "crown" of the stump was probably originally underground, with only the trunks visible. The crown was almost 4 feet across.
An irridescent plant bug, probably immature, rested on the shady side of the stump.
Last fall a buck deer had "rubbed" this mesquite, scraping velvet off its antler, and leaving a message to other bucks in the pasture.
The lotebush berries were beginning to turn bluish. In May, after the mockingbirds and curvedbilled thrashers eat the fruit, the bush will bloom.
More than two dozen Corypantha vivipara cactus were found during the walk.
Was this a buck rub on the lote? Or was it where a packrat had gnawed the bark for food during the winter. A packrat nest was in the bush, but no obvious tooth marks were found. Nor was there a "stringy" appearance (strips of bark hanging loose) as in most buck rubs.
Under the same lotebush, Debbie and Mark Pelham found a Golondrina point, the size of an adult human's thumb. Golodrina points were made 8000+ years ago. Had the packrat drug it home and then discarded it? Why was it laying exposed on the surface? In 30+ years of arrowhead hunting, this was one of the best points of an older age the Pelhams had ever found.
The cleared trail of the packrat was right next to the point.
Spectacle pod was the most common wildflower in bloom. The species had germinated in plentiful December rains, and its roots reach deep into the soil, so they had survived the intervening 4 months of drought and were beginning to bloom.
What made the tiny dark marks in the most tattered blossom (in the upper right hand corner?) Notice the hairy tips to the green sepals behind the petals.
A tiny ground bee clambered over one cluster of spectacle pod blooms, carefully visiting each flower.
A grasshopper nymph rested on another clump of blossoms. The class did not find any adult grasshoppers.
Notice the different stages of the formation of the seedpods (from top left to bottom right.) The one on the bottom right shows why the plant has its common name - the seedpods look like a tiny pair of opera glasses.
Several darkling beetles were found. When disturbed they emit a foul odor from their rear end. Grasshopper mice shove the rear end of the beetle into the ground and eat its head and thorax.
Under some of the lotebushes and mesquite the pits of antlions were found.
A giant ant was found walking alone. It is probably a carpenter ant, but do the roots of shinoaks ever get big enough to be hollowed out for their nests?
Under a piece of trash, another carpenter ant was found, but after a spider had found it. The spider drug it off and disappeared under dried shinoak leaves.
Is this a beefly, a hoverfly or a ground bee? It zoomed away before anyone got a close look.
On the underneath side of an old mesquite log, a paper wasp had built a nest. But who spun the sheetweb above the wasp nest? And why were some of the cells of the wasp nest covered with the same webbing?
A desert cockroach was under another mesquite log.
The most common species of ant was the red "raised tail" harvester (Pogomyrmex maricopa?). They prefer sandier soils. Their nests are usually "half-volcanos" - all of the sand is on one side of the hole, and is mounded high. They do not build "trunk lines" or trails through the pasture, but wander singly gathering seeds. They do not sting as readily as the "rough harvester ants" that clear the soil around the entrance to their hole.
On the underneath side of a piece of wood found in the pasture was this tiny pseudoscorpion. Check out this essay to learn more about them.
A dark jumping spider was on the same piece of wood.
This insect egg was also on the piece of wood.
Was this the species of bug on the mesquite with the balsam apple vine?
A giant longhorned bore emerges in July and flies around at sundown and later. The exoskeleton of one lasted all winter - but did a grasshopper mouse eat its head?
Naturalists flip dung. The center of this cow patty remain on the ground, but a small beetle ran around in circles after the dung was flipped.
Although not a scarab dung beetle, the little guy must have been in that cow patty for quite some time, to have processed so much of it!
In another cowpatty a tunnel filled with "frass" (insect dung) made the observe just what had been there.
A small puffball might have been the center to an earthstar fungus.
Another stalked desert puffball was set upright, although it was found on its side. How long does it take for these leathery mushrooms to finally decay?
One of the class began digging in the soil.
These green leaves were the reason for the digging.
Six of these large roots (the size of a small sweet potato) were dug up from underneath just one of the green clumps of leaves. The plant is canaigre, or dock, a source of tannin for Indians and early settlers. Its seeds are edible, but 2008 was too dry for the plant to bloom.
Despite significant quantities of oxalic acid in the leaves of the dock, insects find it palatable.
Only one Indian Blanket was found during the walk, next to a dock and a sandsage, under a mesquite.
Some of the dock leaves had already withered from the dry spring.
A few turkey feathers littered an open area in the shinoak. Had two males been fighting? Or had a coyote caught one and after killing it, carried it off to its den.
Turkey feathers have a beautiful irridescence.
A bit of rabbit fur was found too. Did the class walk right past a coyote den and never see it?
The small entrances to the home of a pocket mouse lay in the open sand between the shinoaks.
Why did the kangaroo rat push the dirt out of its home in a curving arc - nothing was blocking its way to just go straight, like most kangaroo rat dens.
Deer or feral hog? Deer tracks are pointed at one end and the two parts parallel. Feral hog, the ends are rounder and "splay" outwards just a tiny bit.
During the previous night a coyote had traveled the dirt road, and early in the morning a whiptail lizard had wandered along, as well.
Was this well weathered and broken apart feral hog droppings? Members of the class could never came to consensus.
Old cattlebones were found, along with the old cow patties, but no stock were in the pasture during the walk.
Enamel on teeth takes a while to wear off.
A "newborn" turtle, the size of a half dollar, walked along.
A Swainson's hawk soared over the group. Later in the year, one of the larger shinoaks will be host to its nest.
Had a Bullock's oriole been eaten by a hawk? About 20 feathers were scattered under a mesquite.
Did the scaled quail return countless times to this one location to defecate? Such a collection of tiny bird scat is very unusual!
A sprouting common ragweed was in front of the scapula of a cow.
Being an inquisitive naturalist, a class member turned the scapula over to find a very young coachwhip snake. Unlike adult coachwhips, the small snake did not bite and writhe in panicked agitation. It settled down so everyone could get a good look.
How in the world did Chris Cherry spot the tiny crab spider on a mesquite leaflet?
2007 was a rainy year. Many class members found the old seedstalks of Horsemint, but not one green was found.
A smattering of Tansy Aster were scattered across the pasture.
One tiny cryptantha was found. In wetter years, two species (one with tiny blooms, the other with much larger blooms) can be found in the sanddunes.
A few woolly loco were blooming in the sandy soil. Horses become permanently deranged after eating the species.
One small clump of soapberry trees were found. Small suckers were nearby. The trees seemed to be struggling, barely surviving.
Munroa squarrosa seems to be an endemic grass to the sanddune habitat. It will form mats if it receives plentiful rains.
A few small prickly pear were found. Most likely they are Comanche Prickly Pear, a species with red blooms. It never makes a mound, but just a few pads lying on the ground.
Tasajillo was much rarer among the shinoaks than among the mesquites. Is this because the Curvebilled thrashers nest in mesquite, and not in shinoak, unless the shinoak are tall?
Wright's baccharis is a wiry subshrub found in several habitats. Most people never "see" it - it is just a drab little clump holding down the soil.
Cactus wren nests were only in the mesquite and lotebushes. Their rattling song ushered the class away - when the temperature reaches 90 degrees their song is often the only sound.