In the Heat of the Summer

Friday, July 26, 2013

San Antonio River, Mission Reach, Roosevelt Park trailhead

Today's photo:

The Texas heat high is building and taking firm hold as it typically does this time of year. High temperatures will likely remain in the upper 90s to low 100s (F) for the remainder of the summer. Surface water of any kind, especially flowing water like the San Antonio River, literally becomes very attractive to wildlife.

• The first and second photos are of the characteristic mature inflorescence of Sideoats Grama (the official State Grass of Texas). The detail in the second photo shows the alternate spikelets hanging down from the stem.
• The third and fourth photos are of Maximilian Sunflowers. In the third photo, a Paper Wasp (Polistes sp.) is flying toward the sunflowers. This stand of Maximilian Sunflowers is close to ten feet tall.
• The fifth and sixth photos, the best I can tell, are of a female Powdered Dancer damselfly (Argia moesta). The female Powdered Dancer can easily be mistaken for a male Blue-fronted Dancer, but this one looks more like the Powdered Dancer to me.
• The seventh through tenth photos are of Ceraunus Blue butterflies on Brazilian Vervain. There are two varieties of Ceraunus Blues. These are the Southwest variety. It is worth noting, the Brazilian Vervain (Verbena brasilienses Vell.) is a native, as the name implies, to South America. It has been sold widely in the U.S. as a landscape plant that has become a nuisance invasive crowding out the native Texas Vevain (Verbena halei Small).
• The eleventh and twelfth photos are of a Yellow-crowned Night-Heron quietly watching over its section of the river. This bird has been living here since mid-May. I have seen it on one of these rocks every time I have walked by since then.
• The thirteenth photo is a pair of Mourning Doves enjoying an afternoon on the riverbank.
• The fourteenth photo is a Fox Squirrel having an afternoon picnic in the shade of a Honey Mesquite tree. It isn't visible in this photo, but the squirrel was having a feast on the mesquite bean seed pods scattered on the ground under the tree.
• The fifteenth photo is a general overview of the vegetation on the west side of the River. There is an American Sycamore tree growing among the rocks at the end of the weir. This is probably a volunteer, although the sycamore is one of the more common trees being planted in the restoration project. Sycamore do very well in riparian areas. If one looks closely, a Great Egret can be seen feeding along the riverbank just left of center in the photo.
• The sixteenth and seventeenth photos are of a Neotropic Cormorant drying its wings in the sun as cormorants have to do. Cormorants dive and remain submerged under the surface of the water for relatively long periods of time while they are fishing. To make this more efficient, their feathers are not coated with oil the way many other water birds, such as ducks, are coated to keep their feathers dry. Therefore, the cormorants must hold their wings out to let them dry following a dive.

The Dynamic, Life-giving Yanaguana

Thursday, July 18,2013

San Antonio River, Mission Reach, San Antonio Missions National Historical Park,
Mission San Juan Capistrano, Yanaguana Nature Trail

Today's photos:

The River was the source of life that attracted the Coahuiltecans to live along its banks. They called it the Yanaguana. When the Spanish arrived and began to settle in the area and establish the Missions, it was for the same reason. Rivers are living, dynamic systems, the source of water that supports all of life. The history of this River over the past four hundred years is quite complex, but it continues today to be a source of life and refreshment.

Other than damage to one of the boardwalk sections of the Yanaguana Nature Trail closest to the river channel, this trail not only survived the rain and flooding of late May, the surrounding natural area is flourishing. The rain in June and July has been infrequent and widely scattered as is typical for this time of year. The mid-summer heat has arrived, so the (relatively) cool air of the riparian woods is quite refreshing:

• In the first photo, I was photographing an Alamo Vine with its purple centered white flower growing among a cluster of red flowered Turks Cap when...
• In the second photo, a female Ruby-throated Hummingbird flew in to take advantage of all the nectar in these flowers.
• In the third and fourth photos, my attention shifted from the flowers to the Ruby-throated Hummingbird.
• The fifth through eleventh photos are of a Fatal Metalmark butterfly on a Goldeneye flower. The highly reflective metallic markings on this butterfly's wings are clearly visible in most of the photos in this series. This cluster of Goldeneye was almost 6 feet tall at its highest flower. This particular flower was at about 5 feet, so just a few inches below my standing eye level.
• Photos twelve through fifteen are a small sample of the damselflies that were abundant along the riverbank section of the trail. I haven't had time to definitively identify the species of the ones pictured here, so I'll let it go at that.
• Photo sixteen is a juvenile Yellow-crowned Night-Heron.
• Photo seventeen is a Viceroy butterfly. This is one of the butterflies that can easily be confused with the Monarch.
• Photo eighteen is a Purple Leatherflower.
• Photo nineteen is the bright, translucent red berries on a Pigeonberry.
• Photo twenty is a female Black-bellied Whistling Duck with her three offspring. If one looks very close, there is a dragonfly flying above the head of the last duckling on the right. This photo was taken looking north from E Ashley Rd. These ducks are in the diversion channel from the main flood control river channel to the original pre-channelized river bed below Mission San Juan. 

Elmendorf Lake Park; A Critical Ecological Resource*

Tuesday, July 9, 2013

Elmendorf Lake Park

Today's photos:

Elmendorf Lake is one of numerous critical ecological resources in the City of San Antonio and the San Antonio River watershed. The Lake and Bird Island serve as a major nesting and breeding site for both year around and migratory birds. The duck, heron and hawk species that winter over in Bexar County have flown to their summer nesting grounds. Cattle Egrets, Green Herons and Cliff Swallows have settled in for the summer.

The ecosystem around the Lake is capable of supporting a diverse biological community in spite of numerous water quality and invasive plant issues that have plagued the Lake for decades. The Elmendorf Lake Improvement Project will preserve the bird habitat, including Bird Island, and address the ecological issues. The Project also provides an added benefit of creating an excellent resource for watershed ecology education.

• The first photo is a view looking across the Lake with Bird Island in the foreground. The beautiful Sacred Heart Conventual Chapel and the twin spires of the Main Building at Our Lady of the Lake University are in the background.
• The second photo is a detailed view of Bird Island. The high population of egrets and cormorants is clearly evident in this photo.
• The third photo is of a Broadleaf Cattail inflorescence. Cattail are monoecious plants having separate male and female flowers on the same plant. The female flowers here are the easily recognized "cat tail." The male flowers are higher on the stalk at the top of the photo. The cattail are widely distributed native plants that have a tendency to dominate a wetland habitat creating a monoculture if not controlled. There is an over abundance of cattail growing along the bank of the Lake.
• The fourth photo is a Creeping Water-Primrose (Ludwigia peploides (Kunth) Raven). This is a different species of Water-Primrose than the one I have photographed along the San Antonio River which is Ludwigia octovalvis (Jacq.) Raven.
• The fifth photo is a Green Heron.
• The sixth through ninth photos are of a Neotropic Cormorant taking flight from the surface of the Lake.
• The tenth through twelfth photos are of Trumpet Creeper. This vine is growing on a Black Willow tree on the bank of the large island.
• The thirteenth photo is one of beautiful, large Bald Cypress trees growing along the bank of the large island.
• The fourteenth photo is a Red-eared Slider Turtle swimming in the Lake.
• Also in the fourteenth photo: One of the ecological problems in the Lake is the tendency to have algal blooms, especially in the summer, due to the lack of water circulation and the high levels of nutrients from runoff following rain events. The very high concentration of algae is clearly visible in this photo. The decaying algae falls to the bottom and rapidly depletes the dissolved oxygen creating dead zones below the water surface.
• The fifteenth photo is a Fox Squirrel munching away on Bald Cypress cones.
• The sixteenth photo is a view of Bird Island as seen looking east from the SW 24th St bridge.
• The seventeenth through twentieth photos are Cliff Swallows flying out over the Lake from their nests under the SW 24th St bridge.
• The twenty-first photo is of two Double-crested Cormorants sitting on top of a tree on Bird Island. According to multiple sources, Double-crested Cormorants are rarely seen in Bexar County during the summer, but I have seen several both here at Elmendorf Lake and along the San Antonio River the past couple months.
• The twenty-second through twenty-fourth photos are Cattle Egrets with their very distinctive breeding plumage. There are also Great Egrets and Snowy Egrets nesting on Bird Island, but the Cattle Egrets currently are the most numerous.

* I am resisting the temptation to take While on a Walk in a distinctly academic direction. I have given much thought to the concept of "Critical Ecological Resources" this week. I realized this evening, I have another book to add to my list of "Books in Progress."