Wandering the Southwest Nature Preserve, October 22nd

This year, late October is confused about whether or not it is fall. Today at Southwest Nature Preserve in Arlington, the bright sunshine brought temperatures to the upper 70’s while the trees were beginning to shed leaves and the sumac was a mix of green and red. It was a perfect day for a walk.

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Eastern cross timbers woodland at the preserve

My first objective was to attempt to sneak up on a couple of red-eared sliders basking on a downed section of willow in one of the smaller ponds. One turtle was melanistic, meaning that its colors have been replaced by a sort of charcoal hue on its shell, head, and legs, obscuring the green lines on its body and red patches that should be present toward the back of the head, like two crimson “ears.” The second, smaller turtle seemed to be following in its companion’s footsteps, though it had a little visible pattern on the shell. I took a couple of photos, the last of which caught the big turtle as it pivoted and began to drop into the water.

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The larger slider is in the process of “sliding” off her basking spot and into the water

Pond turtles spend a lot of time basking. They haul themselves out of the water and up on a snag, such as a partly submerged log. Here, they sunbathe to warm themselves and become dry, which may discourage parasites and algae that attach to their bodies or shells. They absorb the ultraviolet-B radiation from the sun, which most turtles need in order to have adequate levels of vitamin D. This vitamin, in turn, allows the turtle to make use of calcium. No wonder pond turtles bask in the sun so much – it’s important for their health in a number of ways. And the choice of logs and branches in the water is a perfect strategy, allowing them to quickly drop into the water and swim down to some hiding place when danger threatens.

Climbing away from the pond and up to the main trail, I was passed by a couple of monarch butterflies, busily working their way southward on their seasonal migration to Mexico. I also noticed some of the other species that I’m beginning to recognize, with Clint’s help. A pearl crescent butterfly visited several small flowers. One of the sulphurs flew by, dancing around in a dizzying flight as I watched to see where it might land. Several tiny moths moved about in the low vegetation. I don’t think it has ever occurred to me how the early fall is a wonderful time to see butterflies and moths, but it certainly occurred to me today!

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A crescent butterfly, probably a pearl crescent

Following the trail up past a series of boulders, a small tuft of grass caught my eye. There, in a crack in the boulder, a few grass seeds had taken root and seemed to be doing well, with one of the plants sending up a tall stalk. It is amazing that the periodic rainfall, the minerals from the rock and tiny accumulated amount of soil could support this little micro garden of grasses!

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A tiny garden of grass on the rock

Further along, I saw a “nest” or comb of paper wasps. These wasps search for caterpillars, cut them up, and feed the pieces to the wasp grubs in the cells of the nest. The development of young wasps is probably finished for the year, and I suppose they will look for shelter when cold weather arrives, overwintering beneath tree bark or in other places that may protect from the harshest cold. This colony was pretty clearly in the genus Polistes, and may have been Polistes exclamans. I like to think that may be the species, because exclamans seems pretty apt for what I’d be doing if I got too close! It is a Latin word, meaning to exclaim or shout.

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Paper wasps

My afternoon would include other members of the order Hymenoptera, but this time it would be Comanche harvester ants. Most Texans’ familiarity with the harvester ant is limited to the “red” harvester ant, Pogonomyrmex barbatus. The Comanche harvester ant (Pogonomyrmex comanche) specializes in open, sandy prairies, and one spot at the Southwest Nature Preserve is an open area of deep sand, perfect for this species. These ants dig colonies that possibly extend six or seven feet below the surface, according to Ann Mayo, who studies Comanche harvester ants. Today, the ants were busily coming and going, perhaps “harvesting” seeds and storing them for the coming winter. They graciously allowed me to take a couple of photos; Mayo describes them as mostly nonaggressive, but has commented that when they do sting, it is memorably painful!

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Comanche harvester ants

My wandering took me out of the sandy meadow and back up into the woodland, where I spotted a wary little Texas spiny lizard, sitting on a small log and watching my approach carefully. A telephoto lens is definitely helpful for capturing an image of this little reptile, which may sit still up to a point and then dash off to the nearest shelter, or up a nearby tree trunk. This one was a young one, possibly a young male. Female Texas spiny lizards are one of our larger native lizards, growing up to 11 inches long (with the tail making up a little over half that length). Males are smaller. To get as close as I could to him, I moved slowly and did not face directly toward him, trying to give the impression that “I don’t see you, no reason to be alarmed.” As I took a photo or two, he looked over his shoulder at me, watching closely. And then, somewhere, I crossed a line that was just too close, and he darted under the log.

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A small Texas spiny lizard

One more encounter lay ahead, with a creature I feared as a child and continue to have a little ambivalence toward. I came around the bend of the trail, and at the base of an oak tree, a haze formed itself into a funnel leading back into a hollow in the tree, and at the doorway to this chamber she sat, perfectly motionless. It was Shelob, the giant spider from Tolkien’s The Lord of the Rings. But it wasn’t, really. In the real world, it was a big funnel web spider, those shy spiders that weave funnels and skitter back into them when a human approaches. This one held her ground, even when I approached with my camera, using the short lens after the telephoto, from a safe distance, failed to produce a good image. I moved the camera in close, my rational self reminding my arachnophobic child-self that the spider was not going to jump on my hand, and in any case posed no danger to me. In fact, Shelob never moved, during or after the photos I took.

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A funnel web spider (family Agelenidae, not the Australian funnel web spider)

I had made the loop around the preserve, seeing a part of it but certainly not all of it. I was tempted to stay, as the sun got lower and the slanting rays gave the woodlands and ponds that distinctive light that comes on sunny days toward the end of the year. Living near this patch of crosstimbers, I visit frequently and have seen it in every season. It is becoming like an old friend, with a rich and treasured history. Like that time Casey and I saw a roadrunner that kept approaching us and would not take “no” for an answer until we let him pass. Like that time Nic and I surveyed the pond, sinking into the muck practically neck deep, ridiculously trying to maneuver a seine around to catch something. Like that magical day up on the ridge when the oak leaves were flaming reds and oranges until you would think the place was on fire. Like the quiet, dark surface of the pond on a winter’s day. Like a hundred other experiences that live in my memory of this wonderful place.

2 thoughts on “Wandering the Southwest Nature Preserve, October 22nd

  1. Lovely recounting of your day, Michael. I’m taking a walk out there tomorrow morning and hope to have some interesting sightings to post.

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