Red Admirals

Last summer, Marlene and I purchased 7 acres of Texas Hill Country above Lake Georgetown, where we plan to eventually build a house and live. The property is forested, with a dense cover of ash juniper, live oak, and shin oak. At least once a week, we walk the property with our Labrador retriever Molly, often hiking the short distance down to the lake, where Molly goes for a swim and Marlene looks at fossils on the beach.

This afternoon, gray clouds filled the sky and rain threatened, but Molly was restless and so she and I jumped in the truck and went for our weekly visit to the property. As we wandered through the woods, we were surrounded by Red Admirals, one of my favorite butterflies. The Red Admiral (Vanessa atlanta) is a beautifully marked butterfly that is unlikely to be confused with any other species. Its wings are velvety black, with brilliant slashes of red-orange on both forewings and hindwings. The front of its forewings are marked with series of distinctive bright white spots.

As we walked among the junipers, dozens of Red Admirals glided around us like miniature sail planes, cruising in and around the trees. I often see these butterflies in juniper forests among the San Gabriel River, although they are found all across North America and frequent many different habitats. Today, they were literally everywhere, in the dense forest, in open spots near the fence line, and along the more open trail to the lake. I even spotted several on the shore of the lake.

Red Admirals are one of the first butterflies to appear in the spring and they fly until early autumn. Their caterpillars feed on several types of nettles. Males are often territorial, defending their resting places from other butterflies and even larger organisms, including humans.

Top 10 Sights Along the San Gabriel River

Below, in no particular order, is my personal list of top sights along the San Gabriel River. These are all views that caught my attention and make the San Gabriel River a special place for me. I invite you to add to the list with your own observations.

Falls at Crocket Gardens – Knight Spring at Crocket Garden is one of the major springs along the North San Gabriel River. After emerging from a cleft in a limestone bluff, the spring runs a short distance before plunging over a cliff into Lake Georgetown. The spring and falls can be seen by hiking the San Gabriel River Trail from the Cedar Breaks Trail head.

Wildflowers Along the River – Wildflowers are abundant throughout the San Gabriel River valley. My favorite spots are along the North San Gabriel between Georgetown and Lake Georgetown and in Berry Springs Park. Among many spectacular flowers is the day flower (right) which grows in shady spots along the river.

Fall Color Along the San Gabriel River Trail – Rounding a curve in the river trail, my breath is taken away by the brilliant autumn colors—the yellow of cedar elms, scarlet of red oaks, and orange of sycamores—on a cool fall morning.

Alligator Gar – Peering down from a Farm to Market Road bridge that crosses the upper North San Gabriel River, I catch sight of a half dozen 6 ft long alligator gar, slowly nosing through the shallow water below like miniature submarines.

Waterfall on the North San Gabriel – One of my favorite sights is water cascading over this low water dam on the North San Gabriel River.

Dinosaur Tracks in the San Gabriel – Scientifically, one of the most spectacular sights along the San Gabriel River is tracks left by dinosaurs that walked the river banks 100 million years ago.

Georgetown Salamanders – Nothing makes my day more than turning over a rock in a spring along the San Gabriel River and catching sight of a Georgetown salamander.

Snowfall on the San Gabriel – An unexpected January snowfall blankets the riverside with a soft white cover, through which peak the tracks of numerous small mammals.

Golden Checked Warbler – This beautiful and endangered species, easily recognized by the bright yellow spots on the sides of its head, is common in Russell Park and Taylor Ray Hollow and other spots around Lake Georgetown.

River Bluffs – Among the most common and yet remarkably beautiful sights along the San Gabriel are the limestone bluffs that often tower 50 feet or more above deep water on a curve of the river.

Shin Oak

A distinctive trademark of the rocky uplands surrounding the San Gabriel River is Shin Oak (Quercus sinuata var. breviloba). This tree goes by a number of different names, including Shin Oak, Bigelow Oak, Scrub Oak, Scalybark Oak, Bastard Oak, and White Shin Oak. A small but beautiful tree, it commonly reaches only 10 to 12 ft in height, although occasionally larger trees of 20-30 feet in height can be found. Multiple stems of Shin Oak are usually found within a few feet of each other, the stems twisting upward in strange and interesting shapes. Its large multi-lobed leaves are light green in color, presenting a delightful contrast to the dark green foliage of the junipers among which it typically grows. The most distinctive characteristic of Shin Oak is its light gray, shaggy, and peeling bark, the origin of one of its other common names—Scalybark Oak.

Hiking the Good Water Trail, I often encounter Shin Oaks scattered among the junipers and live oaks. When I first observed these small trees, I wasn’t sure of the species. Their large, lobed leaves suggested they were part of the white oak group, and their scaly bark and multi-stemmed growth forms eventually revealed their true identity. I love seeing these small and interesting trees as I explore the bluffs and ravines that overlook the San Gabriel River.

The Mexican Buckeye

Last week, as my dog Molly and I walked the San Gabriel River Trail, I spotted one of my favorite trees, the Mexican buckeye (Ungnadia speciosa Endl.), also known as the Texas buckeye and canyon buckeye. Really more of a shrub than a tree, the Mexican buckeye is easily distinguished during much of the year by its reddish brown, three-lobed fruits that hang from the tree and that rattle when shaken. Inside are three large, lustrous black seeds. The Mexican buckeye grows along rocky ravines and bluffs above streams in Texas and New Mexico. The tree Molly and I saw on our walk was actually growing on top of a limestone boulder about 30 feet above the San Gabriel. In the spring, the tree has clusters of small, beautiful pink flowers, which eventually give rise to the fruits and seeds.

The seeds of the Mexican buckeye have been found in large numbers among Native American archeological sites, but experts disagree about whether the seeds were eaten, used as psychotropic substances, or worn as ornaments. The seeds contain compounds that are known to be toxic and there are anecdotal reports of people becoming sick and even dying from eating the seeds. However, several botanists claim to eaten eaten the seeds with no ill effects. Regardless of what the botanists say, I don’t recommend trying them!

Reference: Turner, M. W. 2009. Remarkable Plants of Texas: Uncommon Accounts of Our Common Natives. University of Texas Press, Austin.

Southwestern University Student Projects on the San Gabriel River

Last fall, I taught a First Year Seminar Course at Southwestern entitled A River Runs Through It: The Ecology and History of the San Gabriel River. Students in the course were required to plan and carry out a group research or creative project that focused in some way on the San Gabriel River. Another requirement was that the project include members of the community. Here are brief summaries of the student projects, written by the students.

Memoirs of the San Gabriel River
Bridget Miller, Jessica Perry, Elizabeth Marzec, and Erin Landry

Rivers are an essential part of civilization, both as a cultural hub and a resource. The San Gabriel River and Park is no exception. Despite being an extremely important river in Georgetown and Williamson County, there is very little documented about the river, especially personal tales. We realize that the San Gabriel River is a significant part of the Georgetown community and attempt to convince others of this as well. In efforts to prove the significance of the San Gabriel and collect a lasting oral history of the river, we interviewed residents from all over town, of all ages, to capture feelings and memories involving the city of Georgetown and more specifically the San Gabriel River and San Gabriel Park. We comprised the interviews into a documentary DVD. Through this project we have discovered the positive feelings of fondness that the community has for the beloved San Gabriel River and Park. We hope this film will help teach the residents of Georgetown about the history of the area and for them gain more appreciation for its rich history.

Fossils of the San Gabriel River
Kirby Crone, Kate Castles, Kristen McCollum, Kim Sump

The community as a whole does not know the history of the San Gabriel River and its past, so our group decided to teach them by means of fossils that are found in the region. We hiked along the river and in nearby areas and found nine different kinds of fossils. We classified the fossils and put them into three groups (commonly found, occasionally found, rarely found). We then designed a kiosk to put at the head of the San Gabriel River Trail that has pictures and descriptions of the fossils we found, an illustration of how fossils are formed, and a map that details the geological history of the area. Our project's purpose is to inform and educate the community about Georgetown's past and encourage children to become enthusiastic about science by means of fossils. Fossils commonly found included Turitella, and Texigryphaea. Fossils occasionally found consist of Ostrea, Protocardia, and Pecten. Fossils rarely found are composed of Pholyadomya, Loriola, Tylostoma, and Inoceramus. On one of our many fossil hunts, we went to Lake Georgetown. It was about a twenty minute walk through a forested trail until we got to the waters edge. Right as we were getting there the sun was starting to set, so we had to find fossils quickly. This was not a problem because when we looked down we realized the entire ground was just covered in various types of fossils. By going on each fossil hunt we have been able to see into a world that few have been able to explore. It is truly amazing to see what had been millions of years before our existence and hold that piece of history in your hands.

Analysis of Trash on the San Gabriel River Trail

Kevin Burge, Allard deJong, Alex Essex-Carmona, and Alexander Reinsch

On a hike along the San Gabriel River Trail, these students noticed litter along the trail. They decided to conduct a scientific analysis to better understand where along the trail litter might be a problem and how it might be better managed. An initial hypothesis was that litter was more likely to occur where there were fewer trash cans. The students divided the trail into sections. They collected trash along the trail, recording the number of pieces of trash found in each section and the type of trash collected. They also interviewed trail users to determine their impressions and attitudes about trash along the trail. Results of the study showed that the trail is relatively free of litter and trash. The amount of litter was not related to the presence of trash cans. Instead, areas that contained more litter were located near roads and streets, suggesting that most litter does originate not from trail users, but comes from passing vehicles. Adding additional trash cans is unlikely to decrease the amount of litter that occurs along the trail.